Sticking brake pedal

[Porsche Pilot]

I have posted on Rennlist about my brake pedal sticking on my 99 996 but there havent been any takers.

The symptoms are that the pedal will occasionally stick "on". I need to pull up on the pedal with my toe to free it. It's not severely sticking but sticking nonetheless.

My first thought, based on my highly scientific Google research, was that my master cylinder or some part in the fluid system was bad. All is well in that department and several bleedings by the dealer did not show any concerns with the booster, etc.

So, I got under the dash and have been playing with the pedal. It definitely feels like something is amiss with the pedal assembly itself.

I believe there is a spring there? I didn't see it in the PET. Could a worn spring or bushing cause this thing to stick?

I really hate to have my dealer dig into this too deep as my wallet and fragile nerves can't handle it.

[creekman]

Whooops, I misread the question, I immediately jumped to the conclusion that it was the "clutch" pedal and not the brake pedal.

Sorry...

Edited March 11, 2014 by creekman

[Ahsai]

When the pedal is sticking, do you feel the brakes are dragging. If they are, it's likely due to water intrusion into the brake booster. Porsche has an updated design that eliminates this problem for '99 cars.

Edited March 12, 2014 by Ahsai

[Porsche Pilot]

Let me add just a tad more info. When the car is off, I can fiddle with the brake pedal and feel and hear that it is binding. When pressure is in the sytem, the brakes definitely do drag unless I pull up on the pedal. My non mechanical theory would point to a pedal issue if the system is not active, ie the engine is off. Then again, I really have no freaking idea.

[Ahsai]

Sorry, like Creekman I was thinking about the clutch pedal. There's no spring on the brake pedal as far as I know. Still, water intrusion in brake booster is a well known problem for '99 cars. There's an updated booster and linkage. The water fills up the diaphragm of the booster, which makes it not returning to the rest position even after you take your foot off the pedal.

Edited March 12, 2014 by Ahsai

[Porsche Pilot]

Thanks guys. I will have the tech look at the booster next time I am in.

[Porsche Pilot]

Quick update on the sticky brake pedal. My master cylinder and booster were fine. The sticking was caused by worn bushings in the pedal assembly.

I hope this helps others in the future. Thanks to everyone for the advice.

[Ahsai]

Wow, hard to imagine bushings from pedal assembly can create so much drag. Learn something new everyday. Thanks for the update and glad you get it sorted out!

[Porsche Pilot]

Nobody was more surprised than the shop foreman. He's never seen it either!

[Ahsai]

Glad I'm not alone :)

[artcollinsjr]

Can you describe the repair? (99 996 c4 tip) I have the same condition, a little extra effort to get the pedal started, then it will stick partially down.

I just wasted time and $ changing the m/cyl. But the fluid needed changing so not a total loss

[Porsche Pilot]

Art, I will pull the receipt tomorrow to see if there is a part number for the bushing. The part was fairly inexpensive but labor was the gotcha....dealer prices of course.