3500 S brakes

[Rudiger Wicke]

Just got this request:

"Firstly, the master brake cylinder is 'leaking' oil back to the
reservoir if I don't push the pedal hard. If I push hard there is no problem - so probably the inner rubber needs replacement or do you think that after some use it will get better by itself?

Secondly the front (and maybe also the rear) brake calipers got stuck - They started moving after high pressure on the brake pedal but they won't relaese the discs normally. I tried to move the pistons back with a wrench but it wouldn't work.

Do you have suggestions - do I need to
do a complete overhaul or are there tricks to get thinks moving again..."

Any advice / comments welcome !

Rudiger

 

[DaveHerns]

It won't get better by itself ! At the least it needs new seals in the master cylinder and it sounds like the calipers need overhauling

Not worth taking chances with brakes - sounds like this car has been laid up for a while

 

[P6Rovers]

Dave's right!
This is a road safety concern and we're not as H & S as some countries

If a brake pedal has to be pumped to produce hydraulic action, it sounds like the lip on the seal is worn, allowing fluid to bypass the seal. When the pedal is pumped, the seal splays out a bit and catches the fluid for braking power. That action is not recommended on a hilly road or an emergency stop at an intersection when someone has run the red light on your green.

In my experience, sticking pistons are best freed by removal and examination. It is often likely that a caliper seal kit needs replacing.

The car does seem to have sat a long time. The moisture absorbing properties of the usual brake fluid allows water to sit in various inconvenient places in brake calipers and cylinders sometimes requiring a honing operation, a resleeving process, or installation of an "unobtainium" new part for people living close to the OEM production. Us waifs in the colonies don't have the benefit of easy supply ???

Eric