zubin3333

Hi Guys,

I just fixed my parking pedal assembly. It wasn't returning and I would have to yank it back with my foot every time... I pulled the assembly out of my car and took a look at how it works, and just wanted to explain it so that you know where to lubricate it.

On the brake assembly there is a big spring wrapped around the pedal pivot point, see the photos below. This spring does NOT provide springiness on the pedal. It has cleverly been used as a sort of "continuous" ratcheting mechanism. I.e. allows the pedal to travel in one direction freely but not the other. It sort of works on the same principle as a Chinese finger trap. One side of the spring is fastened hard against the pedal assembly, the other side can move freely. When the pedal is pushed down, the friction between the pedal pivot and the spring works to uncoil the spring and so the spring cant grab the pedal and it is free to move. However when you try to pull the pedal towards you, the friction between the spring and pivot works to coil the spring even more and so the harder you pull back the harder the spring grips.

When the parking brake release lever is pulled back, the spring is manually loosened and so the parking brake is free to return.

Long story short, just lubricate that spring with something like aerosol PTFE while working the parking brake release lever, to get it between the coils (I think its possible without even removing assembly from car). What happens is that the coils start to stick to one another and pulling the release lever only loosens the first few coils while the rest are still gripping the pivot.



Here is a video of me working the release lever on the assembly, you can see how it makes the spring loosen:

Adi-Benz

Good reference, thanks.

JettaRed

iTrader: (1)

Is it just me or does that assembly look over-complicated?

sege

Of course it is a Mercedes