Seized Rear Brake Caliper

[Theunisse]

Noticed a noise from the rear of the car last week and when I looked at the back brake there didn't seem to be much of a pad left! I jacked up the car, axle stands etc and unbolted the caliper and the problem seems to have been caused by the caliper pin being seized. I cleaned it off with emery paper and packed it with copper grease, but it was still sticky. It will have to do though for this week.

I'm planning on buying a replacement set of caliper pins from Brake International so hopefully that should sort it, but I'm wondering if the piston might need its seals replacing as well. I thought I had read on one thread that there is a mechanism inside the caliper piston that helps retract the piston when you release the brake to help the pads back off from the disc.

Any thoughts?

 

[skhell]

I had a similar problem in mine, and by the time I read allot about the problem and how the caliper works.

The thing that makes the piston to retract when you depress the brake pedal, is the piston o-ring, which is a "square-cut" o-ring. Thus, when you it the brakes, the o-ring will deform a tiny-bit, and when you release the brake pedal, the o-ring wants to return to its original position, pushing the piston a small amount, enough to prevent drag.

Probably you only need a brake-caliper repair set and replace the piston o-ring. You could also have a damaged piston, it can be "rusty"...

Also, you should check if your brake hose hasn't collapsed in the inside, not allowing the brake fluid to return, keeping the pressure in the brake caliper.

In my case, I just bought a repair set and the problem was solved. The are pretty cheap, about 15€, per wheel. I bought two of them, one for each wheel, but in the process I damaged one of the rings... In the end I repaired only one wheel...

Give these guys a call or check their ebay store, they have good repair kits: http://www.biggred.co.uk/

 

[Theunisse]

Thanks

I'm going to see how it gets on with the replacement caliper pins first. I think I'll need to keep a closer eye on the rear brakes - only got new pads fitted at christmas! If the problem persists it might be a replacement caliper job.

 

[AndyB1976]

I had a stuck caliper and turned out to be the handbrake lever arm on the back of the caliper which would not return even with the pressure exerted by the return spring.

I think red rubber grease is preferable on the slide pins as copper grease can apparently destroy the rubber boots. What condition were the slide pin boots in?

 

[luvmyaccord]

Exactly what Pedro will see you right mate.

Also, i had the same problem as Andy. Hope it's not the cables though, they're nearly £100 fitted.

 

[Theunisse]

Thanks for the advice about copper grease attacking the rubber. I'll get new rubber seals with the new caliper pins when I buy them. I've ordered some red rubber grease off 'a popular auction site' and I'll give the bolt holes a good clean out and pack them with the grease next weekend. It's behaving itself at the moment touch wood.