Uneven Brake Pedal Travel

[Grim.Badger 15]

I'm suspecting that I have a leaky servo-manifold pipe or master cylinder fault.

 

What happens is that the amount of travel on the brake pedal is inconsistant, a couple of times the pedal has dived to the floor without activating the calipers. Oddly enough though sometimes the braking is much more efficient than normal (they have always seemed a bit crud) with a bite point quite soon in the pedal travel, to the point where it almost catapults me through the windscreen, this is how I like my brakes and how my old diesel used to brake.

If I pump the pedal till its solid then start the car it dips as usual but increadibly slowly seems to creap, but its so slow its hard to tell.

Fluid level in the reservoir seems fine and I checked my pipes about a month ago and they seemed fine. It is possible that the rubbers have collapsed inside but I didn't think that caused this.

Unfotunately the underside of my car is covered in engine oil so I can't tell at the moment if the rear brake pipes are leaking but the fronts were fine last time I checked.

 

Any ideas?

 

Edit: I have previously had problems with one caliper and it recently started squeeling badly (again) so was ready to strip and regrease it again and replace the rubber pipe, but since the pedal problems have come up that caliper has been fine and braking has been more even than usual. The discs are also running much cooler than usual, I always suspected they were locking on slightly as they would always run hotter than my last cars brakes.

Edited April 13, 2007 by Grim.Badger

[C_W 3 1 Cars]

Master cylinder? Or could be a leaky joint/flex leak but I'd expect this to be constant and just pump fluid out all the time.

 

If it was a servo fault, it wouldn't mean the brake pedal would sink down to the floor. All it would mean is that the brake pedal is very hard (but brakes not that effective).

[Dream Weaver 2]

May be worth trying a master cylinder? Try brakesint.co.uk - I got one from them for £22.

[Grez4 2]

yep master cylinder,

 

I had this is my mk1 fiesta. Very scary when you are not expecting it.

 

Perhaps a time to upgrade?

[welshpug 1,631]

yep, one of the guys at Llandow suffered this on his second session, pedla would initially hold the rh/f then let go totally but would hold the lh/f fine and vice versa on the rear (1.9 diagonally split system)

 

quick call to GSF sourced 2, one replacement at £22 and an original Bendix one for £30, incidentally the guy on the phone said its the same as a Mk2 Goluf!!!

[m.i-man 0]

I wouldn't be too sure it's the m/c.... My pedal falls to the floor, and it's defiately not the m/c, so my problem has to be the servo.

Run the checks in the haynes manual for servo fault finding. If it does what it says in there, then you know what the problem is!

[Grim.Badger 15]

Well unfortunately it's stopped doing it so I can't trouble shoot any more, but now the passenger side caliper has started playing up again. Sometimes it clamps partly shut other times it clamps partly open. I've got a wound on my arm I need to let heal before I can do anything about it anyway but I'm going to replace the front brake pipes and see what happens, then replace the MC if that doesn't cure it.