Brake pedal returns slowly

[Ahsai]

My friend's '99 996 coupe's brake pedal returns slowly after the foot is off the pedal. It takes like half a second to return completely and it's very noticeable. The brake fluid may need changing but does it indicate something wrong in the brake master cylinder?

Any help will be appreciated!

Thanks,

- Ahsai

[Alan C.]

How much time is on the brake fluid?

Edited July 23, 2006 by Alan C.

[Ahsai]

We couldn't find any brake fluid flush on the car record (he just got the car) so it's hard to say. We'll plan to try a brake flush first and go from there.

Thanks,

- Ahsai

BTW, it seems to be getting worse now to a point I have to use my toes to lift up the brake pedal after depressing it. It just won't spring back by itself and it's as if the vacuum is sucking the brake pedal down.

- Ahsai

[1999Porsche911]

We couldn't find any brake fluid flush on the car record (he just got the car) so it's hard to say. We'll plan to try a brake flush first and go from there.

Thanks,

- Ahsai

BTW, it seems to be getting worse now to a point I have to use my toes to lift up the brake pedal after depressing it. It just won't spring back by itself and it's as if the vacuum is sucking the brake pedal down.

- Ahsai

Check to make sure your return spring is not broken on the pedal. Even if there was 100% air in the line, the spring should pull the pedal to the top of it's stroke. Also, make sure there is no binding on the pivot point of the pedal.

[Ahsai]

There's no return spring at all on the '99! I think the return spring is a '00 feature. There's no other obvious problems in the pivot areas. Is there a spring inside the master cylinder that pushes the pedal back?

Thanks,

-Ahsai

[1999Porsche911]

There's no return spring at all on the '99! I think the return spring is a '00 feature. There's no other obvious problems in the pivot areas. Is there a spring inside the master cylinder that pushes the pedal back?

Thanks,

-Ahsai

Of coarse there is a spring. If you don't have one, you found your problem. Look above the pedal and you will see a spring several inches long attached to the frame and the other end to the pedal. It is a black spring.

There are also 2 springs in the master cylinder.

[Loren]

The clutch spring is item 5.

[Ahsai]

Argh, I asked my friend to look again and now he found the spring :) Anyway, I'll check it myself later and post an update.

Thanks,

- Ahsai

[jicko]

Item#8 is the "Return Spring" of the Brake Padel

[Ahsai]

Ok, we flushed out the old yellow fluid with Superblue. The old fluid didn't look dirty at all. The problem is still there but the clutch feels smoother though. When I opened a bleeder and pushed the brake pedal, the pedal went all the way smoothly but when I released my foot, it stayed down and did not return!

My guess is a bad master cylinder. We also checked the spring on the pedal but it's really hard to tell how much it's pulling the pedal but it looks fine. The spring is pulling the pedal very close to the pivot point by design, which means it does not have much mechanical advantage.

Any thoughts?

Thanks,

- Ahsai

[Ahsai]

Ok, dealer found that the booster was the culprit. It was full of water inside! One seal is broken that allowed water inside the booster. Got new booster and all the resdesigned parts. Problem solved.

- Ahsai