Will stainless steel braided teflon brake hoses improve the brake's feel on my 993?

On my 993 I replaced the original rubber jacketed brake hoses with braided ones.  With this change, I felt a dramatic difference for the better in brake peddle feel. In a 993 with original hoses having seen 26+ years of use braking will typically display a dramatic improvement in pedal feel. Replacing the original aged rubber hoses with OE style rubber ones may exhibit a similar improvement as well although I have not done this.  

The below information was gleaned from StopTech's brake line FAQ document and is largely relevant to any brand of braided brake hoses. Some of its content is colored by a little product promotion as they sell braided lines so read it knowing this, My editorial comments are enclosed in brackets [_].

Why are flexible brake hoses used in the first place?

From the factory, nearly every production passenger car has short, flexible hoses that run from the fixed, hard metal brake tubes to the calipers (or wheel cylinders as the case may be). These flexible hoses are necessary because the wheel ends are free to move relative to the body of the vehicle. Inflexible tubes would not allow for the articulation of the wheel ends without subsequent failure.

What are OEM hoses made from?

Typically, OEM hoses contain a compliant polymeric (plastic) inner hose to transmit brake fluid pressure from the brake tubes to the caliper. While the polymeric tube itself does a good job of withstanding attack from the brake fluid, it must be protected from the outside world and is consequently wrapped (over-molded) with a thick, rubber coating. Hollow fasteners at one or both ends of the hose provide a direct flow path and a leak-free connection system.

So, how are Stainless Steel lines different?

Stainless Steel lines (they are actually hoses, but we'll use the common term “lines” from this point forward in this FAQ) are similar to OEM hoses in function but differ greatly in execution. Unlike OEM hoses, SS lines [hoses] incorporate a low-compliance [not easily stretched] Teflon inner hose. In addition, instead of covering the Teflon with over-molded rubber a woven braid of Stainless Steel strands is placed over the hose for protection. As with an OEM hose, the ends are terminated with hollow fasteners to allow for the leak-free passage of brake fluid.

So why is that better than the OEM rubber design?

Stainless Steel lines provide a number of benefits as compared to their OEM rubber over-molded counterparts.

• The SS braid provides superior protection from flying roadway debris. [Rubber hoses have been proven to be perfectly adequate in this regard]
• The SS braid and Teflon hose reduce expansion during pressurization. [an assertion]
• They provide the race car look. [fashion statement]

I understand the protection benefit, but can you explain the reduced expansion benefit?

Any time that an object is subjected to internal pressure, it expands. The amount of expansion will be proportional to the amount of pressure present and the rigidity of the holding structure. In the case of brake hoses, we are subjecting Teflon to internal pressures as high as 3000PSI. Because the Teflon is relatively flexible (which makes it ideal for the job in one regard), it will expand under these conditions. This expansion creates additional fluid volume in the hydraulic circuit which is felt by the driver as a soft or mushy pedal.

Rubber over-molding does little to reduce expansion under pressure [assertion that is plainly not true, as rubber brake hoses are commonly used in by virtually all car manufacturers], as rubber is also a relatively flexible material. A woven braid of Stainless Steel, however, can greatly increase the rigidity of the hose under pressure while still allowing adequate flexibility for wheel-end movement. In many cases, this reduced expansion can be felt by the driver as a firmer or more responsive brake pedal.

In addition, the reduced compliance will result in a faster transient response of the brake system. In other words, the time from the driver hitting the brake pedal until deceleration is generated will be decreased by a small amount. The benefit will vary based on each individual application, but in general overall deceleration can be attained more quickly, resulting in slightly shorter stopping distances. [ This statement is problematic as the vast majority of transient response is the small travel of the caliper piston cups as they load up against the pads to push them against the rotors]

What impacts will SS lines have on my vehicle's P-T (pressure vs. torque) relationship?

None. Because brake lines and hoses do not affect the torque generated at the wheel end, the P-T relationship remains unchanged when SS lines are installed. Only changes to a vehicle's caliper, rotor, or brake pad coefficient of friction will impact the P-T relationship.

Well then, will SS lines impact my vehicle's P-V (pressure vs. volume) relationship?

Absolutely. Because SS lines are much less compliant than their OEM counterparts, the P-V relationship will be reduced to some degree (less volume will be required at a given pressure). This is exactly the reason that a car equipped with SS lines has a firmer brake pedal.

However, because the P-T relationship remains unchanged with SS lines, the impact to ABS, TCS, and other brake control systems is typically negligible. Our own BBK kit testing indicates that most ABS, TCS, and other brake control systems are robust to the small changes affected by the addition of SS lines. On the other hand, testing at StopTech (and at major OEMs as well) has shown that while decreases in the P-V relationship typically are invisible to SS lines, increases in the P-V relationship are not (as would be found with an inappropriately-sized BBK).

In summary, because SS lines and a properly sized and balanced BBK only serve to reduce the P-V relationship, we have time and time again demonstrated appropriate system integration with these products. Our in-house testing allows us to make this statement for every platform we service.

Will I feel a difference on my car if I install SS lines?

The amount of perceived difference will vary by each car's individual design, age, and usage. Those cars with a significant amount of flexible OEM line or those that have seen years of use and aging will typically display a more dramatic improvement in pedal feel than new cars with shorter lines. [this also suggests just replacing aged rubber lines with the same will exhibit improvement as well]

What is the difference between lines that are “DOT compliant” and “DOT approved”?

The United States Department of Transportation (DOT) has established numerous standards for automotive components and subsystems. The regulation for brake hoses happens to be FMVSS106. In this document, anything and everything pertaining to automotive brake hoses has been laid out in gory detail – at least, those things important to the federal government.

If a manufacturer claims their SS lines are “DOT compliant”, it means that their SS lines have passed all FMVSS106 requirements, and they have submitted the test data to the government for official certification. This does not mean they are acceptable for use on your car, but it does mean they pass the government minimum standards.

Another term you may hear in this context is “DOT approved.” However, the DOT is not in the business of actually approving or disproving compliance – they don't typically run any tests on aftermarket components themselves. Under these circumstances, one can only surmise that these manufacturers are trying to state that their lines are actually “DOT compliant”, but it never hurts to ask before you buy.

So, do I need to use only DOT-compliant SS lines on my car?

Not necessarily. The DOT requirements must be met in full for official DOT compliance, so even if a SS line passes every performance test but is labeled with the wrong type of tag (or something equally trivial) it would fail certification. While this might mean something to an auto manufacturer or assembly plant, it is meaningless to the performance enthusiast.

All the DOT compliance means is that the lines have passed a minimum set of government standards, which may or may not be important to you. Does this mean that DOT-compliant lines are the best for your car? Not necessarily, but the certification should indicate that the manufacturer understands the product and is trying to hold itself to a certain standard.

[The above statement may be speaking to that the DOT specification may have within it specified design or material criteria that are not relevant to the function or durability of a brake hose and that by definition, the braided hoses are of different construction and material and so by definition may not meet the DOT specification]. We are also to infer that all aspects of the DOT specification are therefore not relevant to the function/durability or safety of the hose assembly.] 

[In context, no domestic manufacturer of brake hoses is going to offer hoses that do not meet the minimum DOT standards for performance, durability, and safety as the risk of failure on a safety-related product such as brake hoses would invite devastating litigation. This is also why one should consider a hose set from a domestic manufacturer who is subject to US product safety regulation and liability law.]

Why do some SS lines have a clear plastic covering?

Under certain conditions, dirt and other abrasive contaminants can find their way between the SS braid and the Teflon inner hose. Over time these contaminants can be ground into the Teflon line to the point that a leak can develop. Naturally, a leak in the brake system is never a good thing.

Some manufacturers have taken the extra step to cover the SS braid with a polymeric coating [plastic] to prevent contaminants from working their way into the Teflon liner. While this coating is not necessary for short-term longevity, hoses without the coating should be inspected and replaced on a more frequent basis.

Why do some SS lines have plastic molded over the end fittings?

Some SS line manufacturers have adopted the practice of molding a semi-rigid polymer over the fittings at either or both ends of the line. These features act as a strain relief for the SS braid where the fitting is secured to the line. In some cases, lines without these features can fail certain dynamic portions of FMVSS106, as the SS braid can wear itself into the Teflon line where it is secured to the end fitting.

Do I need to take any special precautions when installing my SS lines?

In general, no. The most important thing to note is that the routing of the SS line should match either the original stock routing or the instructions included for a new routing (if applicable). Because the SS braid will eventually wear through just about anything (once the protective outer layer is worn away), be sure that there is adequate clearance to all other moving parts under conditions of full wheel travel and full steering.

It should also be mentioned that after installation, care should be taken to examine your SS line routing to ensure that the line is not stressed when the wheels are turned to full lock. This is best done with the wheel hanging at full droop to amplify any routing concerns. Of course, the line should never come in direct contact with any part of the tire, but the line should not be pulled radially with respect to the over-molded end fittings either.

The above information was sourced from: 

https://www.carid.com/stoptech/info/stainless-steel-brake-lines-information.html

Identifying Original Porsche Wheels and their part numbers for a 993

993 Turbo Look Wheel

Seems like the question as to who supplied a wheel is a common discussion among Porsche owners on social media and warrants an answer below:

Outside of certain wheels supplied by the Racing Department or some Special Wishes Department wheels, all stock wheels have a part number and the Porsche triangle-"P" casting symbol somewhere on the wheel. Sometimes on the back of one of the spokes and sometimes in a recess in the back of the hub. 

Standard Alloy Wheel with
gutters along the spoke edges.

Other information such as wheel size or country of manufacturing origin may be present too. If you are wondering if your wheels are the hollow, friction welded spoke variety one can look up the part number, and as an additional feature, the backs of the spokes on hollow spoke 993 wheels are smooth with no gutters in the casting along the sides of each spoke.

Lightweight Turbo Wheel, friction welded hollow spoke.
Available in Turbo/C4 and Carrera offsets.

Add caption

Wheel & Tire Information. Here are some Porsche documents that are useful in researching styles and fitment of wheels for a 993 and other Porsche vehicles as well as tire size fitment. All very useful when trying to determine if a certain OE or aftermarket wheel or tire size will fit your car.

Some wheels have two part numbers cast into a spoke on the back of the wheel. This is the case when one set of spokes is fitted to two sizes of wheel barrels for differing fitment. This can be the case for hollow spoke wheels where the spokes are welded to more than one barrel section to make a complete wheel. In this case, the part numbers are labeled "A" & "B" and near the center hub section of the wheel, there is a small checkbox stamped with an "X" next to the letter "A" or "B" denoting which part number is associated with the complete wheel assembly.

If you found this page informative return to the main page and bookmark it for future 993-related servicing, repair, and upgrading guidance & information.

#hollowspoke

#Turbowheels

#Turbo

#Wheels

#PartNumbers

Fixing Incidental surface corrosion or paint gouges on a 993

A while back I opened my door against the handle of a push lawnmower and made a one-inch-long gouge all the way through the mirror's pant and deep into the white plastic mirror housing underneath OUCH! As an experiment in avoiding having to get the mirror repainted, at considerable cost, I tried the below DIY procedure to good effect where on can't even tell the mirror was ever gouged. 

I would not use this procedure on open smooth areas of the body as the eye is very unforgiving in detecting any variance in the paint in open areas. I would use it on surface corrosion near folds in the metal, small open areas, and edges. 

My car is a light non-metallic color, Speed Yellow. Speed Yellow is also a single-stage paint meaning with no clearcoat and all the top layers carry color. For cars that have a metallic finish or any clear coated painted cars, I strongly recommend testing this procedure in a less visible spot on your specific car first and see if the results are to your liking.

The procedure will clean up any dime or nickel size surface rust or gouges or spot chips. It is not intended to address large area damage to the paint finish. It will also work well for fine chips in the paint that accumulates on the front wings around the headlights.

A modified version of this procedure to address surface corrosion surrounding the windshield and back window on a 993 can be found here.

Supplies:

• Body-color matching bottle & brush touch-up pant;
• 250, 600, 2000, 3000, 5000 and 7000 grit wet sandpaper;
• A "000" Artists paintbrush;
• A box of toothpicks;
• A roll of masking tape;
• lacquer  Thinner;
• New (unused) white Terry Cloth rags or washcloths;
• A plastic squirt bottle filled with water;
• Dupont Perfect-It Ultra Fine Machine Polish or similar;
• An electric hand buffer used with a "foam wheel", both available inexpensively from Harbor Freight.

Procedure:

Initial prep steps for larger than chip areas where corrosion may be present:

• Use some 250 to 600 grit sandpaper to dry-sand any corrosion down to shiny fresh metal; 
• To aid in working in small areas wrapping the sandpaper around a popsicle stick to aid in controlling the sanding area can help; 
• Use care to not sand the adjacent undamaged finish. Using masking tape one can mask off the surrounding area to avoid sanding into it;
• Then wipe or blow off the dust created from the sanding, using lacquer thinner very sparingly on a rag also helps in removing any residual grit, wax or paint sealant that may have contaminated the area.
• Remove any masking tape used to protect the adjacent unblemished paint;

Follow on steps for filling larger areas or spot fixes for small chips in the original paint:

• Remove any previously applied touch-up paint that has been applied to small chips and exhibits overlap of the surrounding unblemished finish. If the previous touchup is sparing in nature it can be left in place. 
• A previously applied touch-up can be removed with a little lacquer thinner sparingly applied on a clean terry cloth rag. The idea being that by using lacquer thinner sparingly it will flash-off dry before it attacks the original paint and just picks up the old acrylic touch-up paint. It will also aid in removing any wax or sealant that may interfere with the adhesion of the repair being contemplated.
• Put a puddle of fresh touchup paint in a small ceramic or metal dish. Do not use a plastic dish as it can contaminate the paint and cause it to not adhere properly;
• Let the paint dry to a thickened pancake syrup like state;
• Apply multiple layers, if necessary, of the thicked paint, allowing for drying between application layers, until it builds up in thickness just above the surrounding unblemished paint;
• Minimize overlapping the new pant over the unblemished finish as it will create a paint ridge around the damaged area's boundary that may require additional work to remove in later sanding steps. 
• For good control on applying the paint to small chips use an artist's "000" paintbrush or a toothpick to apply the paint.
• Once thoroughly dry start with 2000 grit moving to progressively finer grit sandpaper with the water bottle to wet-sand the applied paint flush to the existing unblemished finish that surrounds the repair;
• Use care not to sand through the outer layers of the existing finish adjacent to the repair;
• Use the spray bottle of water to keep things wet during sanding;
• Once done sanding the process can be repeated an unlimited number of times until the desired result of an invisibly flush surface paint repair is achieved.
• When done let the repair sit for a couple weeks to gas-out and harden before buffing with a foam wheel or polishing to remove any dullness in the paint from the sanding process.

If you found this page informative return to the main page and bookmark it for future 993 related servicing, repair, and upgrading guidance & information. If it saved you some coin consider a donation through the button on the top left margin of this page.

#paint #scratch #gouge #body #finish #clear-coat #clear coat#clear-coat #coat #single stage #single-stage

Avoiding and fixing a known problem with corrosion around the Windshield /Windscreen and the rear window

Something I did a few months after having a new Windshield installed:

---

I was reading horror stories about rust-perforated 993 windshield and rear window surrounds due to water pooling in the channel under the black rubber edge molding strip. The moisture also results in ugly corrosion and water leaks into the body of the car. If let go water pooling under the surround leads to an expensive invasive body shop repair. This problem is well understood, is specific to the 993, and became common enough that Porsche added a section covering it in their own shop manual.

Some have proposed sealing the channel by forcing a flexible tube into it, acting like a bead pressing against the walls of the channel. My view is that this solution will unlikely make a perfect seal and still allows for a void under it for any liquid that makes its way past the beading to cause corrosion. 

Below are discussed two separate processes: one to seal the glass-to-body interface, eliminating corrosion around the glass going forward. The other, further down on this page, discusses fixing any corrosion that may have already begun and is visible at the edge of the glass. These processes can be done together in any sequence to address both future corrosion and to repair any spot corrosion that may be present.

Sealing the glass-to-body interface to end future corrosion issues:

Below is a DIY procedure to end the body corrosion issue on the glass surrounds using a sealant on the front and rear glass of a 993. An added benefit to the below procedure is it may also quiet down windshield squeaks that can result from how the windshield was originally set in the urethane mounting adhesive. Also in this document is an additional procedure as to how to repair any spot corrosion that has become visible around the window glass.

Pleae note the 993 has a diffeent glass mounting method than the 964 and earlier 911. 

• The 964 and earlier cars have a single rubber seal that acts like a gasket and suspends the glass in the body opening.  Leaks around the glass is usualy first observed as wetness in the interior lower corners of the windsheild. If you have one of these earlier cars one very effective and easy ways to address a leak around the glass is to force the nozzle tip of a tube of clear 100% silicone bath sealant/calk between the exterior window seal and the glass and the exterior window seal and the body and pump a very small quantity of sealant around the window/winsheild. Any sealant that oozes out can be wiped up and if need be cleaned up with a little solvent. I did this on my '86 Carrera to good effect. The "Cleaning up exposed surface rust" section later in this document will apply to these cars and should be considered before applying the the sealant. I like using the smaller squeze tubes of the sealant as their nozzle is smaller than the calk gun tubes
  
  and can be trimmed to deposit just a very small bead of the sealant. 

• The 993 has front and rear glass that is bonded to the body opening, as most modern cars are today. This is said to cause the glass to contribute to the stiffness of the body. The glass is surrounded by inner and outer molding strips that act as coverings, so the meeting of the glass to the body has a finished look. They are not gaskets or seals, and the outer one does not do a very good job of protecting the edges of the glass from moisture. The exterior molding strip bridges over a gutter in the body sheet metal that surrounds the glass. The first section in this document describes a procedure to protect against future corrosion in and along this gutter and outer molding. 

This procedure pertains to the 993 only:

Note: Read the entire procedure below, all notes, and the follow-on section covering cleaning up exposed surface rust from beginning to end before going any further, as it may influence how you choose to proceed, what supplies you will want on hand, and/or the sequence of steps you choose to follow;

Supplies required:

• Two tubes of Locktite Roof & Flashing polyurethane roofers black sealant**, for calk gun application and 
  
• A caulk gun;
• A new replacement exterior window molding strip if one plans to replace the existing one. See the note in BOLD on this in the procedure below before purchasing the
  
  molding/seal;
• A can of  "Dust-Off" if an air compressor is not available;
• Some rags;
• Mineral Spirits;
• A 1" plastic paint spatula.

** Others have used  the calk gun applied fast curing sealant marketed for automotive windshield applications such as 3M™ Windo-weld Brand or similar. 

Porsche Technical Service Bulletin (TSB) 9501 specifies Bostik 6050 sealant for this application, something I couldn't find when doing an Internet search for it.

I suspect the above 3M™ gun applied sealant will work just as well. 

I wouldn't use silicone or latex claulking/adhesives that may not provide positive adheason, are incompatible with the existing window mounting adhesive or tend to fail over time.

Also, ribbon adhesive such as 3M™ Window Weld Ribbon Sealer that may not provide positive adheason and may leave voids allowing for water egress.

Here is a listing of  three window sealing products with similar features that also may be suitable for this application. 

https://www.3m.com/3M/en_US/p/c/adhesives/windshield/  

I would not use 3M™ Auto Bedding and Glazing Compound listed on this page as it is a non-hardening formula.

The Procedure:

• In preparation remove the outer molding strip and blow out the channel along its bottom edge with air. You may be surprised by the amount of water that spatters out. You may find that the outer molding strip was previously glued down in places. If this is the case it may get damaged and will need to be replaced once removed.
•  If one doesn't have a compressor a can of camera/computer cleaning dust-off will work well. 
• In my case no moisture blew free indicating things were already dry.
• 
  Don't be too concerned if you see the plastic track the outer molding strip presses into has cracks or broken sections. If it does not adequately hold the molding in place when reapplied a small amount of 3M Super Weather Strip Black Adhesive can be used to tack it down if needed once everything is dry.
  

Note: Be aware you may need to replace the molding strip with a new one once removed. If you do this plan to have a new outer molding strip on hand if you plan to apply it while the adhesive is still wet later in the process. Also, trial fit any replacement strip before beginning this procedure as some available in the aftermarket seem to not fit properly, either not lapping the entire channel or are too short. " From a Porsche TSB on the subject: "When replacing the rear window in cars built before July 1994, a new rubber trim part number - 993 545 225 02 must be used. If the rear window is not being replaced then the rubber trim, part number 993 545 925 00 is to be used. Cars built from July 1994, use the rubber trim, part number - 993 545 225 02."  

 Also, I recently (8/2024) read a posting by Ed Hughes on Facebook

that the aftermarket windshield rubber trim part 993.541.925.00 offered by URO is slightly wider (2.0mm~2.5mm) than the dealer-supplied part and may resolve an issue with the OE trim part not being wide enough to fully lap the gutter around the glass.

If you are replacing the windshield in conjunction with the procedures on this page you might find the section on windshield sources about midway down this page next to an image of a windshield:

https://993servicerepair.blogspot.com/2021/02/words-of-wisdom-page.html

• If you are working on the rear glass and your car has a high-mounted center stoplight that sits flush to the exterior glass the body color matching cover is just held on by friction clips.  
• The cover can be pulled off revealing a nut on each end of the frame holding it to the glass; 
• Push down gently on the frame surrounding the  nuts and remove the two nuts to release the frame; 
• Unplug the two wire connectors to the frame's light fixture; 
• Set the fixture aside, you now have access to the upper section of the glass top molding strip.
• Dust, dirt, debris, or loose corrosion may have accumulated in the channel. To encourage good sealant adhesion any debris should be removed and the channel wiped clean. 
• One can wrap strips of terrycloth around the tip of the plastic spatula or other more rigid plastic or wooden object as a tool for this. 
• Run the tool into the channel moving the tool along it to pick up this contaminant and wipe the sides of the channel. 
• Use multiple strips of cloth as each becomes dirty. 
• Avoid using something hard as a tool, like a screwdriver, as it may scratch the paint or nick the glass forming a propagation point for a crack in the glass.
• Mask off the black plastic track that surrounds the glass so the added sealant calk when applied does not get on it and interfere with the outer molding strip from being pressed back into it when reapplied. 

Note: Some may prefer to address spot corrosion before filling the channel with sealant and replacing the molding strip. If this is the approach used make sure the applied touch-up paint is fully dried before applying the sealant. See the section below "Cleaning up exposed surface rust where the molding strip meets the body:"

• Load the tube of sealant in the caulking gun and slit the applicator tip slightly diagonally to form a moderate size end opening. Then puncture the calk tube sealing membrane at the base of the applicator tip by sticking a wire or nail into the applicator tip.
• With the channel dry, starting at the top center of the glass slip the nozzle of the caulk tube vertically directly into the channel. 
• As the sealant is pumped in it will ooze upward in the channel indicating it is nearly full as one moves along it. 
• Pump the sealant in as one works their way around one side of the window to the center bottom fully filling the channel with the sealant calk flush to its top edges as they go.
• Slow down as you approach the bottom sides making sure the channel completely fills in the lower corners where a surprisingly large amount of sealant will need to be applied;
• Continue to the bottom center of the glass;
• Then begin at the top center again and worked one's way around the opposite side of the car to the bottom center.
• Once dry the masking tape can be removed and the original or replacement molding strip can be reapplied. Some prefer to apply the molding strip while the adhesive in the gutter is still wet using the adhesive to both seal the gutter and tack down the molding strip. If the plastic track the molding strip is pressed into is damaged or has parts missing this is a good way to help the molding stay down. If you apply the strip to the wet adhesive the strip will be permanently affixed so if later removed it will need to be replaced with a new strip.

It may take more than an entire tube of sealant to complete the above process as there is a rather large space in the channel on these cars. Work to minimize any sealant overflow as it will subsequently need to be cleaned off the surrounding body and the outer molding strip once the strip is reinstalled.

Clean-Up after the seal/molding is reinstalled:

• Use multiple dry rags to wipe the excess sealant from the car and the molding strip. 
• Go over it again with a clean rag wet with mineral spirits to pick up any small amount of sealant that was left on the glass, molding, paint, and where the edge molding meets the body paint.

Ideally the above should be done on a clean rust-free channel for example shortly after a new windshield has been installed. I suspect that even if your car has corrosion in the bottom of the channel this process will halt the steady march of future corrosion. Unlike other materials used to fill the channel the above completely fills the void and has extremely good adhesion to both sides of the channel drying to a hard rubber consistency.

How durable is the 993 sealing/calking procedure:

The calking installed by the above procedure has been in place on my daily driver 993 for +/- ten years now on the rear and front glass. It has proven to be durable and eliminates the corrosion issue while keeping the outer molding strip cover flat and in position. Below is a picture of my daily driver 993 taken recently:

 Pictured is the lower right-hand corner of the rear-light glass where I had repaired some surface corrosion that had migrated out from under the molding strip using the method described below. It is a place where rainwater collects and so one of the more common corrosion points on the glass surround on a 993. In the picture, I have pulled the molding strip up.   Note the bottom band of black rubber is the applied sealant in the body channel/gutter. It has become covered with dirt and debris from the intervening years of environmental debris that has made its way under the molding strip. Even so, it exhibits complete sealing continuing to provide complete protection to the body from moisture egress and corrosion. 

Also, note the vertical crack in the top black band, the track the molding strip is pressed into. Cracks or even broken-off sections of this track are very common and should be of little concern. If one finds the molding fails to stay down for any reason including a cracked or broken track, a dab of 3M Black Super Weatherstrip adhesive can be used to tack it down.

Cleaning up exposed surface rust on the 993, 964, and earlier 911 vehicles where the molding strip meets the body:

A follow-up DIY procedure is to clean up any dime or nickel-sized surface rust that may have already appeared at the edge of the glass. If you went ahead and filled the gutter with sealant, wait a week or two for it to fully harden so it doesn't contaminate the paint during the procedure below.

Supplies:

• Body-color matching bottle & brush touch-up paint;
• 250, 600, 2000, 3000, and 5000, or 7000 grit wet sandpaper;
• A roll of masking tape;
• A plastic squirt bottle filled with water;
• A one to two-inch painters' plastic spatula;
• Toothpicks;
• A "00" or "000" artist's paintbrush;
  
• Dupont Perfect-It Ultra Fine Machine Polish or similar;
• Optionally, an electric hand buffer is used with a "foam wheel", both available inexpensively from Harbor Freight.
• lacquer  Thinner.
  
  
  

Procedure:

• Pry up and hold the rubber edge molding clear of  the spot of corrosion using the plastic spatula if the edge molding strip is not to be removed.
• Use lacquer Thinner very sparingly on a clean cotton rag to remove any
  
  residual wax or paint sealant contaminants that may interfere with paint adhesion in the area that you will be working on.
• Use some 250 to 600 grit sandpaper to dry-sand the corrosion down to shiny, fresh metal; 
• Use care to not sand the adjacent unblemished finish. Using masking tape, one can mask off the surrounding area to avoid sanding it.
• Then wipe and blow off the dust created from the sanding, followed by using lacquer thinner very sparingly on a rag, removing any residual contaminants that may interfere with paint adhesion.
• Put a puddle of the touch-up paint in a small ceramic or metal dish. Do not use a plastic dish as components of the plastic can contaminate the paint and cause it to not adhere properly.
• Let the paint dry down to a thickened pancake syrup-like state.
• Apply multiple layers of the thickened paint using a toothpick or a small "00" or "000" artists' brush, allowing the paint to dry between layers until it builds up in thickness above the surrounding unblemished  paint;
• Minimize overlapping the new paint to the surrounding unblemished finish to avoid a ridge from forming in the paint in later sanding steps;
• Remove any masking tape used to protect the adjacent unblemished paint.
• Once thoroughly dry, start with 2000-grit sandpaper, moving to

  

  
  

  
  progressively finer grits in conjunction with the water bottle to wet-sand the applied paint flush to the existing uncorroded finish that surrounds the repair. A suitable assortment pack of sandpaper of various grits can be purchased on Amazon or at any automotive supply store.
• Use care not to sand through the outer layers of the unblemished paint adjacent to the repair.
• Use the spray bottle of water to keep things wet during sanding.
• Once done, sanding the process can be repeated an unlimited number of times until the desired result of an invisible paint repair is achieved.
• When done, let the repair sit for a couple of weeks to gas-out and fully harden before buffing or polishing to one's liking.

I did this repair on my car which is finished in single-stage (no clearcoat) paint. For cars with a clear coat finish the results may vary and larger patches of rust may not match to ones liking. In any event, the above incremental repair will not interfere with the subsequent alternative to overspray the entire window frame, for most a bodyshop activi

CRW from Rennlist asked some insightful questions concerning sealing the window channels:

Q: Once the sealer is in place it's there for good - not easy to remove - correct?

A: If one used sealant from a calk gun, the polyurethane stuff it is pretty much permanent.

Q: What happens if the glass needs to be replaced in the future?

A: If the glass needs to be replaced sometime in the future the sealant can simply be left in place or if any touches the glass in spots it can be trimmed off so I do not see this as an issue going forward.

Q: Does the sealer shrink away from the channel with time and temperature similar to how similar products do around windows etc?

A: In the case of latex calk used on home structures, they gas out over time, shrink and pull away, the stuff used to mount the glass and the stuff used to fill the channel is not water-based latex and so does not shrink over time.

Most every application on a home including roof & widow flashing sealant that is polyurethane, the sealant fills gaps between two or more elements. These elements tend to move back and forth against one another with temperature cycling and so can fail over time. This is not the case with the channel as both sides of it are part of the same contiguous piece of sheet metal.

 Also urethane products have much better adhesion properties than latex or silicone-based sealants. Silicone products are not compatible with the sealaint used to mount the glass and so really should not be used for this application.

If you found this page informative, return to the main page and bookmark it for future 993-related servicing, repair, and upgrading guidance & information. If it saved you aggravation, time, effort, or some coin, consider donating through the button in the top-left corner of this page. 

 

#window #windshield # Windscreen #backlight # Gouge #rust #corrosion #seal #gutter #molding #glass #molding #strip

IMMO BLOCK A product that avoids the Key Fob double-tap to start a 993!

 

I rarely endorse third-party products but this one is truly plug-and-play and completely eliminates the timing-out function of the ignition when the car is left to sit while still immobilizing the ignition when the doors are locked. Most importantly it avoids doing expensive internal ECU and fusebox/relay modifications to achieve similar results that can cause technical problems down the road and are not easily reversed when sorting out Ignition/Alarm/Immobilizer issues or when selling the car.

The 993 comes with an ignition immobilizer function as an anti-drive-off security feature. It is enabled in two ways. 

• One when the doors are locked using the electronic key fob and the other; 
• When the car is simply left to sit for three minutes or more.

The annoyance comes into play when one has a good reason to leave the car standing for greater than three minutes forcing one to double-tap the fob or fiddle with the fob button while the key is in the ignition to disable the immobilizer. This happens every time: 

• One goes out to the garage to use their 993 having sat overnight with the doors unlocked;
• One fills their tank with gas;
• One takes their 993 in for service sometimes resulting in a call from your mechanic asking why their car won't start or from simply; 
• Sitting in your car or washing your car;
• Also, when using the On-Board Diagnostic (OBD) port one needs to disable the Immobilizer to use the reader.

Doing the double-tap dance also causes literally hundreds of unnecessary door lock actuations potentially leading to excessive door mechanisms' wear. This is the dollar value proposition of this product, by avoiding just one servicing of the door locking mechanism will pay for this product. 

I installed the IMMO- BLOCK in my 993.

https://www.ezimmoblock.com/

• Works on USA and CANADA-delivered cars;
• Just plug it in, and the installation is completely reversible;
• Has an internal 9-volt battery that has a service life of about two years;
• If the internal battery dies the immobilizer still functions normally as it did from the factory until the battery is replaced;
• It does not require internal software changes to the BOSCH Motronic Control unit as other products require;
• It does not interfere with key fob programming/mating to the car. The procedure for mating fobs can be found here.
• It disables the normal door chime function as it replaces the door chime relay behind the gauges in the dash;
• It does not add any meaningful draw (parasitic battery loss) to the overall electrical system;
• I added aftermarket automatic door locks and a headlight /turn signal left-on chimes to my car previously and it doesn't interfere with their function;
• For those engineers among us who want the option to eliminate the 9 Volt battery internal to IMMO-BLOCK, Here is a page that describes how to do it.
• Designed and manufactured by a really nice guy Jay Mingrone, jay@EZimmoblock.com, who is very active on rennlist.com and gives great communication and support;
• This product will not address existing system faults causing the door LEDs to flash in couplets, the Immobilizer status light in the clock to flash, losses of the ability to mate keyfobs or other faults with the Alarm/Immobilizer system. Look here to resolve such issues.

UPDATE 11/21/2021 

I have now had it in my daily driver 993 for quite some time now and have found it to be quite an enjoyable and reliable upgrade with no issues.

UPDATE 08/17/2022
Just replaced the battery in the unit in my car. It lasted about two years. Easy to replace.

UPDATE 2/19/2023
Jay now offers a procedure to eliminate the battery for those who desire this.

Here is a page describing where an IMMO BLOCK customer  did the conversion on their car as a DIY effort:
https://rennlist.com/forums/993-forum/1336932-converting-immo-block-to-eliminate-9v-battery.html

NEWS FLASH... 1/29/2025 Jay of IMMO BLOCK fame now offers economical replacement remote entry fobs for the 993 that are completely compatible with the 993 and can be mated using the factory procedure on this page. 

He also offers second generation fob that will allow these new fobs to be mated (cloned) from any existing fob that is presently mated to your 993. He calls this fob the F2. This is a significant development in that some find it challenging to mate additional backup fobs to their 993 using the factory procedure. 

A description of how to use these new cloned fobs can be found at the bottom of this page:

https://www.ezimmoblock.com/

An inexpensive backup key to go with the above fob:

If you are looking for an inexpensive backup key to go with the above fob,

I recently had a 993 key made for me at a "KeyMe" kiosk at Walmart.

https://key.me/kiosks

The machine scanned my somewhat worn key, and it appeared in my home mailbox within a week. The completed key works perfectly in my ignition.

The key is not the pretty Porsche-branded key, as it is made from a standard aftermarket non-Porsche key blank. If you are considering purchasing a replacement electronic remote fob from IMMO BLOCK to make a backup key+fob set, this is an inexpensive alternative source for a key.

Great companion additions to a 993 IMMO BLOCK are:

• Automatic Door Locking;
• Headlight warning buzzer
• Window control with the key out of the ignition 

If you found this page informative, return to the main page and bookmark it for future 993-related servicing, repair, and upgrading guidance & information. If it saved you some time, aggravation, or even a little coin, consider a donation through the button on the top left margin of this page.

#IMMO # imo #BLOCK # Block #IMMO-BLOCK #Immobalizer #Anti #Plug-and-play #fob #electronic  

How to read the Temperature/Oil Level/Oil Pressure Gauges on an Air-Cooled 993/964

 

The 993/964 has dry-sump lubrication where: 

• The volume of oil in reserve is scavenged from the engine bottom and stored in an oil tank. 
• Where it is pumped and distributed to the engine. 
• The system holds about 12 quarts of oil in total and; 
• At an oil change just short of 10 quarts is drained and replaced if you follow the procedure to change your oil listed on this page.

Calling the engine air-cooled is a bit misleading as it is in large part oil-cooled by the rather large amount of oil circulating in the system. It even has a fan-driven oil radiator called an oil cooler, much like the coolant radiator in a water-cooled engine. Being a dry-sump system, the gauges related to oil are not just read directly at face value; they need to be read under specific running conditions, and a little interpretation is needed to arrive at what is going on with the oil system.

First of all, the system is dynamic: 

• Pumping oil at various rates dependent on engine speed and; 
• Fluctuating oil viscosity based on oil temperature. 

For these reasons, the amount of reserve oil volume in the oil tank varies quite a bit by engine speed and oil temperature, 

Also both: 

• The oil volume gauge in the dash and; 
• The dip-stick; 

give a measurement of the oil volume in reserve in the tank, not in an engine oil pan as is the case in most other vehicles featuring wet-sump lubrication systems.

The dynamic nature of the volume of oil in reserve in the tank is why the oil level is measured under the following specific conditions:

• The engine fully warmed as on a 70F to 80F day after a twenty-minute drive, where the oil pressure gauge that was pinned to the top when cold has fallen into its normal operating range between 2 and 2.5 Bar at idle.
• With the car on level ground;
• With the engine running at idle;
  
  
  
• Measured by way of the dip-stick, not the gauge. The dipstick is more accurate in absolute terms and the gauge only approximately correlates to its measurement. 

Once the behavior of the gauge is understood for a specific car, it can be a leading indicator that one needs to check their oil level with the dipstick. 

For example, in my specific 993 the gauge floats in in the red zone when the oil is properly filled via dipstick measurement.

Also, the entire scale of the dipstick and the oil gauge is a lot less than one quart in oil volume.

To measure the oil under the above conditions it is properly filled if:

• Dip-stick fill level measures at 1/4 of its measuring scale from the bottom;
• Overfilling is more of a problem than underfilling in a 993, as the system holds so much oil. Overfilling will result in excess oil being sucked into the air intake gumming up the works and possibly contributing to problems such as a clogging the emission air injection system. Overfilling can also lead some to conclude that their car is burning oil, suggesting the need for internal engine work where no such condition exists. 
• Filling the oil into the proper measure fill range using the dipstick with a cold or not-running engine will result in grossly overfilling the oil.
• The fill level, even under the proper conditions, should never be "topped off" to the top of the dipstick measuring range. This will overfill the oil.

When properly filled under the above conditions the gauges should show the following approximate conditions;

 

How the gauges should approximately look when
 the engine is fully warmed on level ground at idle.

• Oil temperature gauge at approximately between 7:30 and 8:00 o'clock position;
• The oil level gauge is at about 1/4 of its scale from the bottom, if properly calibrated.
• And the oil pressure gauge is between 2 Bar to 2.5 Bar, depending on the viscosity rating of the oil and its exact temperature. On my car with a 40-weight oil, it sits below 2.0 Bar; with 50-weight oil, it sits at or just above the 2 Bar mark.

Even if the oil level is a little low so when fully warm and idling it just moves slightly off the dead bottom of the gauge's red section there really should be little concern about oil starviation due to the large amount of oil in the system overall and the less than a quart mesuring range of the gauge.

 Here is a Do -It-Yourself  How-To for changing the oil on a 993 without overfilling the oil tank and information about other 993 body fluids.

At speed above idle the gauges will show: 

• The oil pressure gauge does little more than tell you if the engine is oil starved if the pressure is not above 3 Bar above idle, it should be between 4 Bar and pinned at the top, most of the time.
• The oil level gauge is of no value and will likely just sit at the bottom above idle. 
• The temperature gauge, if at or above 9 o'clock, tells you your engine is running hotter than it usually does. This can be normal in hot weather (90F+), especially sitting in traffic or when extreme demands are being made on the cooling system, such as in an autocross event, just coming off a timed run, or sitting in the run queue.
• When the oil temperature gauge is slightly above 9:00, the low-speed blower for the oil cooler in the front of the car should kick in, and one should be able to hear it. If you are not sure if your oil cooler blower is working at low speed, a known issue with the 993,  see the bottom of this page to learn how to test its operation.

As one drives the car hard and it heats up further in warm weather:

•  The warmer the oil the greater the amount of oil retained in the oil tank and the oil level gauge reads higher at idle;
• The warmer the oil, the lower its viscosity, and the lower the oil pressure that will be read on the oil pressure gauge at idle.

So, as the temperature gauge rises to 9 o'clock or beyond, the oil pressure gauge can fall just below 2 Bar at idle, and the oil tank fill gauge can rise to the halfway point or above. 

Oil viscosity will affect what the gauges read. If one uses a 50-weight multi-grade oil, say Mobil 1 brand FS X2 5W-50 in warmer climates (85F+), and finds their oil pressure regularly dips below 2 bar with a fully warmed engine, one can consider a heavier 60-weight oil at their next oil change. Look for an oil with slightly higher zinc levels, of 1100 parts per million (ppm) versus. 900 ppm in other Mobil 1 oils. This higher level is recommended for our cars to protect the valve train, but not so high, as up to 1850ppm found in motorcycle or racing oils, which may shorten the life of the catalytic converter.

That blue plume of smoke occasionally at startup:
In the normally aspirated, non-turbo car, an occasional plume of blue smoke can be observed at startup. Some say it is due to the boxer layout of the engine, where some crankcase oil seeps past the rings as the car sits idle and burns at startup. Others suggest it is the result of oil fumes vented from the case/oil tank to the intake that has condensed on the inside of the intake manifold and is pulled into the engine at startup and burns. In any event, an occasional plume of blue smoke is normal for these cars. If it is a constant issue, the oil fill level should be investigated also a higher viscosity oil can be considered in the absence of other gross running symptoms. I would not worry about it too much.

Special Considerations for the Turbo model variant: 

If your 993 is the Turbo variant there are special considerations to avoid oil smoking at startup. One theory is when at rest some oil may backflow into the turbo lubricating system and can cause a small quantity of oil to leak internally to the turbos. This oil will burn at startup making for a blue plume of smoke.  Some argue that this is not plausible because at startup the turbos are cold and any oil present will not be hot enough to initially burn and cause immediate smoking. Another theory is much like in the normally asperated Carrera oil vapor is vented to the intake, condenses on the inside of the intake plumbing and is immediately ingested and burns at start-up and causes the plume. In any event here is what some have done to minimize smoking at startup.

• Switching to a heavier-weight oil, preferably one with higher zinc levels, > = 1000 PPM. I have come to understand this elevated zinc content reduces the scuffing of components in the valve train.
• Verifying the oil filters used have the internal valving to limit the back-flow such as the  Porsche branded Turbo specific filters, the valve can usually be observed through the oil passageway holes in the bottom of the filter.;
  
• Making sure the oil is not overfilled (lower 1/4 of dipstick), probably having the most influence.

•  There are also aftermarket oil line check-valves available claiming to address this problem systematically.

In Conclusion:

By filling one's oil to the proper level and observing the gauges one can infer an adequate oil volume is in the system and how hot it is.

Andy

If you found this page informative return to the main page and bookmark it for future 993-related servicing, repair, upgrading guidance, and information. If it saved you some time, aggravation or even some coin consider a donation through the button on the top left margin of this page.