sotal Posted August 16, 2014 Share Posted August 16, 2014 My inlaw has a 200tdi which has a little issue with the brakes. My inlaw changed the discs and pads and pushed the pistons in on the calipers to do this. Since replacing the brakes are rubbish and your foot goes right down they do just about work but not good at all. He has tried to bleed it and there doesn't appear to be any air in it. Somebody said something about pushing the pistons in and how it can do something in the master cylinder - is there something that can go wrong and if so how do you fix it? Any other suggestions? Thanks. Quote Link to comment Share on other sites More sharing options...
Puffernutter Posted August 16, 2014 Share Posted August 16, 2014 Could it be that now the pistons are pushed further back in, if they weren't cleaned first, any ring of rust/corrosion that was outside (as the pads were thinner) is now in the bore and causing friction? Cheers Peter Quote Link to comment Share on other sites More sharing options...
Nigelw Posted August 16, 2014 Share Posted August 16, 2014 It is the pedal movement that troubles me, if the pistons didn't move and were seized then the pedal would just be solid. Your inlaws know the sequence for bleeding the 200Tdis twin pipe system? there are three bleed nipples on the calipers. Quote Link to comment Share on other sites More sharing options...
sotal Posted August 16, 2014 Author Share Posted August 16, 2014 I don't know, I ended up driving it round the fields the other day for a few hours doing some jobs - luckily only in low box so plenty of engine braking. Each time you pressed the pedal your foot went right down to the floor but it would stop - but not with a great deal of confidence! Wouldn't the pistons eventually come out if it was pumped and then if there was friction - cause it to stick out? Quote Link to comment Share on other sites More sharing options...
sotal Posted August 16, 2014 Author Share Posted August 16, 2014 It is the pedal movement that troubles me, if the pistons didn't move and were seized then the pedal would just be solid. Your inlaws know the sequence for bleeding the 200Tdis twin pipe system? there are three bleed nipples on the calipers. He said something about the fronts having 3 nipples and needing to do 2 together then the top one on it's own (I may have that the wrong way round but pretty sure it was something like that) - seemed to know what he was on about. He's had the 200tdi for years and done the brakes a few times. Quote Link to comment Share on other sites More sharing options...
qwakers Posted August 16, 2014 Share Posted August 16, 2014 ive got the same issue that started after bursting a brake pipe and running the system dry.(i have obviously bled the system since.) gonna change the master and see what happens. will report back Quote Link to comment Share on other sites More sharing options...
sotal Posted August 16, 2014 Author Share Posted August 16, 2014 Thanks - will be interesting to see if a direct replacement just sorts it Quote Link to comment Share on other sites More sharing options...
Sheffield Posted August 17, 2014 Share Posted August 17, 2014 I have a similar problem since I replaced the pistons, two of which were stuck solid, with new stainless steel ones. When I release the brakes, the pistons seem to move back into the calpiers by about half a millimeter, which has to be taken up again when the brakes are applied, causing a bit more travel then I would like. I did wonder if the wiper seal lips were doing this, and have tried pressing the brake pedal without the pads in to move the pistons out a bit more, but it does not seem to have cured it. The brakes do not feel as if there is any air in them, and are solid once the pads are hard against the discs. Just a bit of travel on the pedal. Is it possible in view of the comments about the master cylinder that the master is drawing fluid back on release? Quote Link to comment Share on other sites More sharing options...
Team Idris Posted August 17, 2014 Share Posted August 17, 2014 Maybe I just thunked a fix? Pull a rear pad, push the piston out a bit with the pedal. Then push the piston back in until the pad is a push fit between disk and piston. Then repeat on the others. - Basically I think that making the pistons last movement "into the caliper" rather than out will keep the pad pressed against the disk, so no sizable oil volume is needed to stop the car. Quote Link to comment Share on other sites More sharing options...
qwakers Posted September 8, 2014 Share Posted September 8, 2014 Thanks - will be interesting to see if a direct replacement just sorts it just to come back to this. my replacement master was duff. made it worse. i put a rebuild kit on the master and that fixed it. but whilst i was at it i decided it was time for new disks and pads, and as my front calipers were knackered i replaced them too. i replaced 2 bake pipes too..... so it could have been any of the above. Quote Link to comment Share on other sites More sharing options...
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