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thread: What are the chances of two faulty callipers?

  1. #21
    adamh's Avatar
    Mar 2005
    south east
    4,439
    I've already swapped the callipers Adam, albeit for second hand ones which look in good condition and the mechanisms are free and clean. The discs are okay and the surface is flat, I have another set of discs too as I bought full a set of discs and callipers from someone who was breaking a car. It is possible that the original and the swapped callipers are both in need of refurbishing but having chucked loads of cash at a simple problem already I thought I'd throw it out there for ideas.
    great , object of exercise being i.d the condition of the disks !, it did not sound like them but ya didnt mention them, just crossing out a blank.

    edit, btw.. go and get some use into the new pads before you get it into the test place, go drive round a few housing estates carefully, try and bed the pads in a bit more , you can have the best rebuilt brakes in the world, they will still have a reduced braking force until they bed in proper.

    slotted and grooved discs and ebc red stuff pads.. (assuming all kit is new) don't share so much the same failures!..they just stop you quick.

    old disks and new pads is bad, i used to re-dress my discs on the lathe if i used new pads.
    Last edited by adamh; 04-12-2014 at 21:11.
    ......in the bluecorner , fighting out of japan....

  2. #22
    ya_crow's Avatar
    Apr 2014
    Stratford upon Avon
    166
    I got the car on a ramp for a few hours yesterday and the first thing I found was that one of the pads wasn't seated properly, the nobble on the back of the inside pad wasn't lined up with the Chanel in the piston. That would account for a lot.

    So I then proceeded to wind the piston back in. It reached a dead stop before it was flush and it still protruded about 1mm when wound fully in. I then wound it back out 180* but it then protruded too much and the calliper wouldn't slide over the new pads. I put the old pads back in for now and reassembled it all, put it on the rollers and it now pulls 100 on the o/s (double what it was) compared to 150 on the n/s. The foot brake pulls an even 200 both sides now that the pad is seated correctly.

    I don't know if the handbrake efficiency will be enough to pass the MOT on Monday or not yet. But also I have a new set of pads which have too much meat on them even without the rattle shims to fit. It's only a tiny amount. I ground the nobble off the back of the pad so I didn't have to unwind the piston any more than 180* to line them up but I'm a fraction of a millimetre away from being able to slide the calliper over the pads.

    Or am I being really thick and doing something obvious wrong? Has anyone had trouble refitting the calliper with new pads? Bearing in mind that the disks are not new there should be enough space in there.

  3. #23
    Woodsport Paul Woods's Avatar
    Mar 2005
    Durham, UK birthplace of the 1.5,v6 and v8 Mr2
    14,617
    You need to wind the piston back in all the way, then try winding out just so it meets the pad, it doesn't have to be exactly 180*, but as you've seen there is nothing wrong with your calipers, just the wrong proceedure.

    You're almost there.

    TB Quote of the month:"I split my ear open whilst masturbating" - Jasper Full story Here

  4. #24
    snowtigger's Avatar
    Sep 2007
    stockport
    5,475
    Did you slacken the hand brake or disconnect from the handbrake pins on the caliper like Paul has said?

  5. #25
    thomp1983's Avatar
    Apr 2012
    Newark, Notts
    906
    It's possiibly a lip on the disc stopping the pads going

  6. #26
    ya_crow's Avatar
    Apr 2014
    Stratford upon Avon
    166
    The discs are in fairly good shape from memory, but surely new pads ands new discs should fit so even if there was a slight lip they should still fit? Any lip is not going to be wider than a new disc I'd have thought.

    Anyhow, thinking that the whole calamity was over, it went in for another MOT today and apparently now that same calliper is leaking fluid from around the piston. We must have damaged the seal or something when winding the piston in and out?

    New calliper ordered and it'll be in for a retest on Friday or Saturday. Who'd have though that such a simple thing could cause so much grief. Hopefully my next post on this thread will be to say that it's got 12 mths ticket as you guys are probably as bored of my brakes as I am.
    Last edited by ya_crow; 10-12-2014 at 18:18.

  7. #27
    snowtigger's Avatar
    Sep 2007
    stockport
    5,475
    It's better than watching shitenders or horrornationstreet.

  8. #28
    nads1978's Avatar
    Jul 2013
    E.Mids
    176
    Some light entertainment about the subject when i was told how wrong i was from people who didn't know better, makes funny reading 10 years on.

    http://www.imoc.co.uk/forums/viewtopic.php?t=6372

    I was going to post this on your link, over on IMOC, but I can't post pictures there, new member, need more posts - can't be arsed.
    I'll post it here, it may help someone out. Maybe.

    ************************************************** *********************************************

    I know it's an old thread, but it has helped me out (Thanks Paul), So I thought I'd back up Paul & help to illustrate with pictures... We all like pictures right?!
    It's on my Mk3, I guess it's similar to the others?

    This is the screw, about which the piston will wind in/out. It is locked so it can't rotate. It can push, which is what it does when handbrake is pulled.
    You will see that unlike a regular screw thread on a bolt, it has multiple threads running together; meaning it can start (unlike a bolt) in more than 1 position [this is important to understand for later].





    I have wound the piston right in & parked it in the finished position.
    It is protruding 2.5mm from the casting:




    I wind it out 180deg and park it in the finished position.
    It is protruding 6.6mm [so we have travel of 4.1mm]:





    Lets consider what Paul was saying about clearance of brake pads... What if they now wont fit? Well, panic not. Paul said to wind the piston back to the start position, but 'overshoot' by 1/8 of a turn. As before the start point is 2.5mm:




    Lets wind her out, to the final position, 180deg + that 1/8 turn. What has happened here, the piston adjusting mechanism has picked up on a different thread on the main shaft (remember, earlier I said about the threads?). Now we have a protrusion of 5.5mm - so we have travel of 3mm. 1.1mm more room for the pads than the 1st attempt:
    Last edited by nads1978; 18-06-2015 at 18:24.

  9. #29
    Woodsport Paul Woods's Avatar
    Mar 2005
    Durham, UK birthplace of the 1.5,v6 and v8 Mr2
    14,617
    Great pics!

    TB Quote of the month:"I split my ear open whilst masturbating" - Jasper Full story Here

  10. #30
    Torero's Avatar
    Nov 2008
    London
    1,100
    You can't get much clearer than that.

    “Where I'm going is not nearly as important as what I'm driving to get there.”
    ― Jay Leno

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