Rear brake problem - seized caliper?

[tom_the_bomb]

Hey guys, this is my first post, it looks like a great forum I hope someone can be of help.

I just bought myself a 172 cup after years of saving - very happy with the car but after only a week it developed a scoring/scraping noise from the nearside/left rear. I took the wheel off and decided a seized caliper was to blame. However having removed the caliper it appears that the disc is making contact with the hub and the noise was being made by the two big caliper retaining bolts fouling the inside of the disc..! The caliper piston itself seems stiff but not completely seized (also it might be worth mentioning the dust guard is missing).

I'm going to have to replace the disc and both these bolts. Can anyone tell me why this has happened? Is there anything i need to bear in mind when replacing the disc?

Thanks for reading, any suggestions would be massively appreciated.

Tom

 

[Silent_Scone]

do Cups have a rear bias valve?

 

[Ian_s]

Sounds like someone has changed the discs and not replaced the spacer, it will be stuck to the back of the old discs!

 

[tom_the_bomb]

Cheers for the quick responses. I'm not aware of a rear bias valve, i'll have to look that up. Re the missing spacer; the pads and disc look pretty new so it is likely someone's had them off recently. If a missing spacer was to blame, does it make sense that the disc would work as it should initially, then rub against the hub a few weeks later? if there was a spacer missing i'd assume the disc would be rubbing from the word go :S thanks again!

 

[mitch1503]

id go for the spacer as mine was exactly the same when i bought mine

 

[CraigIrl]

The disc would ride to close to the rear beam without the spacer. It'll more than definitely be that

 

[tom_the_bomb]

Cheers for the help guys, you were spot on. I've had the disc off and found that the deflector had come to pieces.. Any ideas whay that might have happened? I put on a new deflector and second-had brake disc with a wheel bearing pressed in. I put everything back together and the original problem is solved. Now however there's a knocking noise from the rear left.. It gets more frequent as I drive faster but isn't associated with any bumps in the road. I don't think the exhaust or tank is to blame and there's nothing loose in the boot. Any ides what could cause this? Thanks again

Tom

 

[tom_the_bomb]

Also here's what the hub looked like.. the stub axle was slightly deformed (circled red) which i thought might be causing the problem? i do intend to change the whole hub when i can afford to..

 

[Tigger]

Can't see the pic Tom

 

[tom_the_bomb]

Hey, still haven't worked out how to upload photos sorry. Have sorted the problem now and thought i'd update the thread in case anyone else has similar difficulties.. It was all caused by the deflector between the rear disc and stub axle falling to pieces. As a result the disc ground away at the caliper carrier and made a real mess of things (my fault really for driving her home after the noise started..). I've now replaced the stub axle (which got rid of the knocking noise), disc (inc bearing), caliper carrier, deflector and caliper retaining bolts (the ends of these were fouling the back of the disc). Got all the bits second hand to wasn't too pricey thankfully.

I think the deflector shattering occurred because it was installed the wrong way round (although it was difficult to be sure because it was in small pieces). I found out that the side that is cut away should be against the stub axle and the squared off side should be against the wheel bearing/brake disc.

Thanks for your help, hope this is of some use to someone!