|
Torn boot
When it got cold this fall in my clutch pedal stuck coming up the last 2” on three or four occasions. Now that the car is stored for the winter, I pulled off the floorboard to investigate. Besides a wide array of dusty filth, the boot behind the clutch pedal is torn, as expected. I don’t defer maintenance on this car, but I’d love the peanut gallery to chime in telling me this boot is totally unnecessary, and that simply ignoring it won’t hurt anything. Better yet, I should remove it all together and enjoy the benefits of saving almost a full gram of weight. Unfortunately that’s not what you’re going to say. How hard is it to replace this boot? I can’t tell exactly what else needs to come off or how to get to it. I have access to the car, but it’s logistically impractical to attempt any large-ish projects like removing the whole pedal cluster and then bleeding hydraulics after re-installing. Like most of my 993 issues this may need to be repaired with a VISA card come spring because prior experience has demonstrated that once the weather is warm I’m just not willing to trade full days of precious driving time to work on the car. Disclaimer: I know for a fact I’ve read about clutch pedals sticking, including at least one thread about an entire pedal box rebuild as a winter project (possibly 964 forum). I did search, unsuccessfully. I’m prepared to be flamed, (and deserve it), but please include a link with your vitriol. Thanks! [img]blob:https://rennlist.com/c4b24249-da53-439f-b2f5-dc63ede79433[/img] -Mark |
The boot does a very poor job of sealing anything even when fully intact as with each compression and expansion it pumps air in and out of the folds. In theory, the bellows protects the plunger rod from surface corrosion that will ultimately shorten the life of the master clutch cylinder. With that in mind, I would tape up the old bellows or cut it off and replace it with a new one split in half long ways so it can be simply slipped over the rod. A little oil sprayed on the rod will go a long way in displacing moisture.
Sometimes less is more when it comes to maintenance & repair. Andy |
The sticking of the pedal may be your kinematic lever. Porsche has redesigned it several times . Do a quick search on kinematic lever and you see a bunch of threads. Replaced mine in about couple hours and sticking pedal was cured.
|
It isn't difficult to replace just the boot, but I don't have the part number for the Porsche boot (if one is available as a single part). However, the boot in the Tilton Engineering clutch master cylinder rebuild kit is a perfect fit. The kit is part #TIL-75-625RK, available at this link:
https://www.summitracing.com/int/par...25rk/overview/ No need to remove the master cylinder, just disconnect the rear end of the pushrod, take off the old boot, replace with new, reconnect. While you are in there, you may want to lubricate any bushings or other contact points to preclude sticking. I use Wurth HHS 2000 or LM Hi-Tack Lube Spray, which goes on as a thin oil and seeps into the smallest spaces, but quickly changes to a high-temperature grease that stays put. The end of the master cylinder pushrod is secured only by a clip. Put a length of dental floss through the clip, so you can find it if it decides to fly away, then remove it. I used a small forceps to pull the clip off while releasing it with a screwdriver. Then use a small pry bar or similar to take off the tension, and lever the pushrod sideways off its pin. No need to disassemble anything. Withdraw the old dust boot. Put some rubber lube or similar on the orifice of the new boot, and it push it onto the pushrod. You may need to push harder, as the chorus girl said to the archbishop. Manipulate the clutch pedal to line up the parts, lever the pushrod back onto its pin, install the retaining clip, button everything back up, pat yourself on the back, have an adult beverage. The hardest part may be getting the throttle linkage pushrod to snap back into the pedal. Clamp the pushrod with a small Vicegrip, and push down hard on the pedal. |
Thank you both. I see my picture of the torn boot didn’t load. Luckily an iPhone photo of a torn boot isn’t exactly National Geographic level artwork. Shortly after I first rescued the car from semi-garage queen status a little over a year ago, the clutch pedal clicked a bit from time to time and felt a little stiff/numb. After some research I figured kinematic lever was the cause, but bleeding the system cleared it right up. In general it seems the more I drive this car the better it works, and over 11,000 miles later the pedal has been fine. I’m not sure how quickly kinematic levers fail, but since it only hung up a few times this fall when ambient temps were near freezing and the car was cold, I’m thinking the lever may be just starting to stiffen and the cold pushed it over the edge. For now I’ll lubricate what I can reach, tape up the torn boot, and plan to repair it all as soon as symptoms consistently appear. Hopefully that’ll be in 2035. Thanks again. -Mark |
Bobby T- We must have been posting at same time. Thanks for that. If the boot is removable with everything else intact, my OCD will probably preclude the sensible “tape it up” option. I’ll see if I can figure out how to get the old boot off, doesn’t sound too hard. -Mark |
I replaced mine with the Summit racing part, it wasn’t too difficult. I wouldn’t leave the shaft “bootless”. |
Originally Posted by BobbyT
(Post 15426606)
It isn't difficult to replace just the boot, but I don't have the part number for the Porsche boot (if one is available as a single part). However, the boot in the Tilton Engineering clutch master cylinder rebuild kit is a perfect fit. The kit is part #TIL-75-625RK, available at this link:
https://www.summitracing.com/int/par...25rk/overview/ No need to remove the master cylinder, just disconnect the rear end of the pushrod, take off the old boot, replace with new, reconnect. While you are in there, you may want to lubricate any bushings or other contact points to preclude sticking. I use Wurth HHS 2000 or LM Hi-Tack Lube Spray, which goes on as a thin oil and seeps into the smallest spaces, but quickly changes to a high-temperature grease that stays put. The end of the master cylinder pushrod is secured only by a clip. Put a length of dental floss through the clip, so you can find it if it decides to fly away, then remove it. I used a small forceps to pull the clip off while releasing it with a screwdriver. Then use a small pry bar or similar to take off the tension, and lever the pushrod sideways off its pin. No need to disassemble anything. Withdraw the old dust boot. Put some rubber lube or similar on the orifice of the new boot, and it push it onto the pushrod. You may need to push harder, as the chorus girl said to the archbishop. Manipulate the clutch pedal to line up the parts, lever the pushrod back onto its pin, install the retaining clip, button everything back up, pat yourself on the back, have an adult beverage. The hardest part may be getting the throttle linkage pushrod to snap back into the pedal. Clamp the pushrod with a small Vicegrip, and push down hard on the pedal. "take off the old boot, replace with new, reconnect." Could you please share some further detail on this step? I am good up to taking off the old boot, but I simply can not slide the new boot down the pushrod because the part to which the pushrod was previously attached is most certainly in the way. Is there a step implied in here that I am missing? Thanks so much. |
| All times are GMT -3. The time now is 09:36 PM. |
© 2024 MH Sub I, LLC dba Internet Brands