Siezed rear calliper

Bungy

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I'm slowly ticking my way through the list of standard GSA faults and the latest one is a siezed rear calliper. I managed to remove the slide from the calliper which wasn't easy as I kept the brake line connected but off it came. The slide bolt was heavily corroded and although it cleaned up well enough for now I'll be getting a new bolt and dust seal. Probably worth checking out the fronts tomorrow evening.
 
The rear brake can be fitted with new seals for about £20. However, front seals are sold only with new pistons at over £60 per caliper.
 
its normally the sliders not the piston that seize up,done mine twice ,uneven pad wear is a sure sign :thumb
 
Sliders on mine were fine. Who knows why but piston seals were questionable. Saying that the brake felt no different with new seals so maybe I spent £20 and the hassle for nothing.
 
its normally the sliders not the piston that seize up,done mine twice ,uneven pad wear is a sure sign :thumb

Absolutely spot on there as once the slider finally gave in and it was all stripped down the pads had started to wear uneven and it was the front slider that was stuck solid. I have freed it all up but I will be ordering new today and replace next week when it arrives.
 
The sliders on mine had been greased with copper slip. I used some posh Rocol stuff (semi dry lube) I've had in the shed for who knows how long.
 
This is why it's a good idea to remove brake callipers, free off the pistons and clean the sliders, which should be lubed with a smear of copper-slip grease. This should be part of a standard annual service but it isn't and won't get done unless you ask, or do it yourself.
 
A slight update as I went to the dealers today. I've got new pads and new rubbers that came in a pack with a tube of grease and is a Brembo item, but no slider bolt. Apparently they do not sell them and they come with a calliper? Anyone know where I can get a bolt on its own?
 
Had same problem couple of years ago, no one sold the pins. Did find a guy in the states making stainless ones but cant find the thread I posted on here now. It was on the ADVrider forum so a search may show up the details. Have worked a treat and never had a problem since. Picture is of new one and original, even cleaned up it was still badly pitted.
 

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Mine were polished but the wear was not measurable with a micrometer. There was none of that pitting and chattering damage.

If you want perfection you'll actually need TWO new bolts or two that are not chattered. Then what about the bush into the caliper body? With bolts that bad the bushes must be toast as well.

Edit:
That sort of damage happens when the parts are fitted dry or with unsuitable grease. Salt and water gets under the bellows and the rest is predictable.
 
Mine were polished but the wear was not measurable with a micrometer. There was none of that pitting and chattering damage.

If you want perfection you'll actually need TWO new bolts or two that are not chattered. Then what about the bush into the caliper body? With bolts that bad the bushes must be toast as well


Edit:
That sort of damage happens when the parts are fitted dry or with unsuitable grease. Salt and water gets under the bellows and the rest is predictable.

Mine was completely dry with no sign of any grease
 
When you come to reassemble it I would recommend you use red rubber grease on all the brake moving bits except the pad pins ( aluminium based grease). The red rubber grease is designed for the job and it doesn't cause the rubber to expand like some other greases can. Never had a seizure in 15 years.
 
When you come to reassemble it I would recommend you use red rubber grease on all the brake moving bits except the pad pins ( aluminium based grease). The red rubber grease is designed for the job and it doesn't cause the rubber to expand like some other greases can. Never had a seizure in 15 years.

I would use red rubber grease on the piston seals but nowhere else on the caliper.

Red rubber grease is sticky, attracts dirt and causes excessive wear. Ditto the brake pad landing points.

The pins and pad edges hardly move so need a high solids anti seize compound. So called copper grease is too greasy (attracts dirt) so get proper stuff from someone like Rocol. Its not cheap but a tube will last for ever.
 
I would use red rubber grease on the piston seals but nowhere else on the caliper.

Red rubber grease is sticky, attracts dirt and causes excessive wear. Ditto the brake pad landing points.

The pins and pad edges hardly move so need a high solids anti seize compound. So called copper grease is too greasy (attracts dirt) so get proper stuff from someone like Rocol. Its not cheap but a tube will last for ever.

Sorry just to be clear I use red grease on the rear calliper slides and all Pistons as well as the front and back master cylinder push rods that lurk behind the dust bellows. I use a version of copper slip but with aluminium in it on the pads, pins and where the pads touch the calliper. So far after 104k miles never had a problem with dirt.
 
Red rubber is handy stuff but as you say not great for everything. Ive just had my petrol pump out of the tank. I had to carefully lift it with a screwdriver (like a paint tin lid but more careful). Definitely not dig into the seal. Putting it back was impossible without red rubber great on the inside edge. No grease on the seal to tank side of course. I also use it on wiring connectors. As ever, they still have to be levered apart but don't stick solid like dry connectors can do.

I used to have a tube of Rocol very high solids moly anti seize but its recently run out. It was so much better than the usual stuff sold for car fasteners. MolyKote is about the most similar type available these days. Very not cheap and hard to find in small tubes.
 
Stripped my rear calliper down again tonight to fit new rear pads, rubbers and apply the Brembo grease that came with the kit. It all came apart nicely so i measured up the pin that I can't buy and did a sketch. I'll get some made up at work in marine grade stainless steel for replacement later.
 


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