front brake caliper servicing - advice reqd please?

[andycook]

had a look at left hand front brake caliper this evening - as the 4runner has been pulling to right on hard braking

the culprit seems to be the 2 inboard pistons, - the seals have split for a start.
I put a peice of wood inbetween pads, the 2 outer pistons moved in, and the inboard ones didnt budge - HOWEVER the caliper wasnt bolted in place, and peice of wood was floating.
I held the outbaord pistons in place with a clamp, and managed to get the inboard pistons to push out. The piston surfaces are pitted with rust - seals gone too.

question is, the rust pitting suggests I need new pistons. Is it worth getting new seals, pistons - or should I assume the piston guide surface on caliper is similarly got rust on it?
OR might it be more cost-effective to get a whole new caliper from milners (and would the new caliper include pistons and seals for the £75 ?)?

andy

[Elvz]

Buy the new calipers!!! If the pistons are rusty the caliper bores will be rusty too. To rebuild a pair of calipers you would need 8 pistons at £8.50 each and 2 rebuild kits at about £20.00 each. That's around £104! You would also need to split the calipers and hone the bores until the rust pits are gone, which can be quite time consuming.

[andycook]

thanks

however - if only 1 of the calipers is dodgy, can I not just replace that?
rather than both of them?
andy

[Morr]

thanks

however - if only 1 of the calipers is dodgy, can I not just replace that?
rather than both of them?
andy

You can replace just 1 caliper, but its really not best practice. If one has gone dodgy/rusty, how far behind is the other? the new one may brake far more efficiently than the remaining old one leading to uneven breaking. Personally I always try to replace certain items in pairs purely from a safety perspective, in this list I would include Discs, Drums, Shocks, Tyres, Wheel cylinders and Calipers.
I know many will happily replace these items singly, but when it comes to safety related items I like to play safe.

[NiftyNev]

You can replace just 1 caliper, but its really not best practice. If one has gone dodgy/rusty, how far behind is the other? the new one may brake far more efficiently than the remaining old one leading to uneven breaking. Personally I always try to replace certain items in pairs purely from a safety perspective, in this list I would include Discs, Drums, Shocks, Tyres, Wheel cylinders and Calipers.
I know many will happily replace these items singly, but when it comes to safety related items I like to play safe.

Very good advice.

Neville

[andycook]

thanks chaps

thats what I susepected

its like my neighbour who replaced a dead rear shock on her her subaru, I recommened she replaced both with new ones. She went for the cheap option and got 1 from a breaker to replace it, now the other one has gone dead and shes looking for a another 2nd hand one for that...

ive found a place doing reconditioned calipers with new pistons, seals and boots for £59.95 - which seems ok

andy