Peugeot Expert Brake Problems

[connor_clark]

Hi, Ive got a job on at the moment, a 2007 Peugeot Expert that came in with braking issues, i found it had very low pads so the pads changed all round, after that was done whilst bedding them in i found the pedal was sinking half way then going hard so i changed the master cylinder and bled the eintire system including the abs pump using our delphi diagnostics system to activate the pump. went out on a road test again and found the pedal then turned rock hard as if it had a loss of vacuum or a faulty servo so I started to dig around with vacuum pressure etc and found the vacuum at the servo to be exactly the same as that of a known working van which left only one real possibility - the servo is faulty so I changed the servo and still no change to the pedal. ive checked that the servo linkage isnt siezed and the master cylinder is correctly aligned to the servo ram and am now starting to run out of ideas.

i know the fiat scudo had a recall regarding the vacuum pump having a valve that isnt compliant and the drive pin playing up but the pump shows no symptoms of being faulty, ive heard several horror stories regarding these vans now and people going without their van for weeks on end whilst sveral garages and main dealers pick through it to no avail so any help would be much appreciated

[danthevan]

First thing i'd do is swap the m/c back with the old one just to rule that out.
Are there no brakes at all or just damn heavy?

[connor_clark]

the old master cylinder has seals gone, theres a visable fluid leak from it so thats that already ruled out, ive since tried a vacuum pump from another van and a vacuum pipe without the non return valve and still no difference... the pedal feels exactly as if the servo doesnt have the vacuum pipe attatched the brakes do work but its very hard to push the pedal down

[danthevan]

seems like you've been thorough with it then.

Teaching grandma to suck eggs etc (sort of thinking logically of hydraulics!), i'd start at the m/c cracking open the brake lines to rule out if there is a pad / caliper jammed somewhere, especially if the seals on the old m/c were shot.

[connor_clark]

That's the plan for Monday but I can't see it's going to prove anything because it seems to be a servo oriented problem because of the symptoms it's showing, the pedal feels like there's no servo fitted