Ford Mondeo 1 (1993 - 1996) - 1996 auto - New master cylinder now brakes seizing

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Mon 7 Apr 2008 09:21
1996 auto - New master cylinder now brakes seizing - Richard Huddleston
ABS model. Fitted new master cylinder (pattern), replaced fluid & bled all wheels, now after 20-30 pumps on the road all 4 corners seize. Undoing one bleed nipple releases them all. The pedal is very high so the ABS cuts in early. Any ideas other than faulty cylinder (it certainly looked & fitted the same as the old one)? Thanks in advance.

Edited by Dynamic Dave on 25/04/2008 at 19:15

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Mon 7 Apr 2008 10:05
New master cylinder now braked seizing - scotmech
Have you left any free play on the rod that attaches the master cylinder to the servo ... you might have to use spacers to achieve play ... or did you discard any spacers? ...

If the the rod is not returning fully the fluid will be trapped in the brake lines ...

Edited by scotmech on 07/04/2008 at 10:06

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Mon 7 Apr 2008 11:21
New master cylinder now braked seizing - Richard Huddleston
Thanks. Wondered if that might be it, can't remember any gaskets etc, and there were none with the new part. Might have to blag a look on Ford's computer.
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Mon 7 Apr 2008 14:05
New master cylinder now braked seizing - Screwloose

Try locking the brakes hard on and then releasing the master cylinder fixing bolts; if it releases the pressure, then it's a cylinder/servo issue.
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Fri 25 Apr 2008 17:01
1996 auto - New master cylinder now braked seizing - Richard Huddleston
Turns out there?s an adjuster on the rod that actuates the master cylinder, but you can?t see it unless someone pushes the brake pedal then it pokes out of the servo. So get them to do this, grip the outer locknut with mole grips and adjust with a socket. I had to also put thicker O ring to take master cylinder further back from servo.
Trouble is you don?t know how far to back things off until it?s all bolted up and road tested. By unclipping the air filter top & ducting & wiring it?s just possible to pull the master cylinder out far enough without draining it; be careful.
I think the pattern cylinder was to blame but it was £60 instead of Ford?s £172. Might be worth measuring against the old one before fitting and rejecting if not the same.

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