efil4sbuD 0 Posted August 24, 2007 Hi guys, My OSR caliper siezed on my Corrado so i have swapped both rears with a set from a mk2 until i can source another Corrado rear. I have bled the brakes with a pressure bleed kit and thought i'd got all the air out but my pedal travels almost all the way to the floor. My OSR caliper now rattles while i'm driving so i guess that there's air in it which has stopped it from gripping the disc. It's tight while the hand brake is on so at least that works. Does anyone else agree that this is my problem, just air in the OSR? If so, do i need to have the engine running whilst i bleed it as someone has mentioned? (it has ABS). Can i only bleed it properly with VAG COM as someone else mentioned? Also, do i need to pump the hand brake or the pedal during the bleed? I also found that the slide bolts were not all the same, one on each side was smooth, one had marks on it like it was tapering towards the end, can anyone shed any light on this? Unfortunately i don't know which one came from where so i hope this has nothing to do with the caliper not working. Thanks, James. Quote Share this post Link to post Share on other sites
VEEDUBBED 0 Posted August 24, 2007 Right,two months ago a friend of mine asked me if i could look at the brakes on his old fiat tipo,rare model fitted with ABS AND disk rear brakes.I had to change the rear pads and the only way possible to get the new pads in and push back in the piston was to detach the entire caliper and put it in the vice,undo the bleed valve and push/turn using the O/E Fiat brake winder tool,that bloody piston when still connected would'nt budge no matter how hard i used the tool. A lot of mucky brake fluid shot out that had been there since 1990,brake fluid was never changed... As a last resort try it. Quote Share this post Link to post Share on other sites
efil4sbuD 0 Posted August 25, 2007 The caliper isn't seized, i've had the piston out and changed the rubbers. It's just not gripping the disc like the others and so it's wobbling about while i'm driving. This lack of grip on the disc i'm putting down to the fact that there must be air in the caliper which gives me the less than confident feel at the brake pedal. This is probably down to the fact that i haven't bled the brakes properly which is why i was asking for clarification of how exactly it needs to be done on a car with ABS, engine on? pump brake pedal etc. Quote Share this post Link to post Share on other sites
Roger Blassberg 0 Posted August 30, 2007 It's normal to have one parallel-sided guide pin and one tapered/stepped. I can't say for certain if it is important which one goes in the top and which in the bottom (of the caliper!!!). Did you wind the piston back out to give the required clearance to the pad backplate? Did you clamp the pressure regulator when bleeding to open it fully? Have you bled the master cylinder? Best wishes RB Quote Share this post Link to post Share on other sites
efil4sbuD 0 Posted August 30, 2007 Thanks for your advice. Tonight i seem to have finally fixed the problem. Yesterday i bled the brakes again (4th time), this time with the engine on, that firmed the pedal up. Tonight i had the wheel off and found that a bolt holding the pad carrier had come out allowing the carrier and caliper to lean onto the disc which was the cause of the awful noise i've been hearing. I nicked a bolt from my mk2 and got it back in there for the time being. I'll have to get some new ones as they have a locking compound on them. Maybe that is how it came out in the first place, because i used old bolts. Unless i never put it back in when i had the beam off, maybe thinking that i'll do it later and forgot :? Anyway, all sorted... for now. Quote Share this post Link to post Share on other sites