cosrep

I just started to rebuild the calipers and staight away ran into problems, I took the dust seals off the four pistons and gave them a good soak in WD40, put the caliper flat on a bench, put a piece of 2x1 in the middle and hooked up an air line, turned on the pressure and one piston popped out but the others did'nt budge now all the pressure is escaping through that one cylinder?

Theres no were to get a grip on the pistons and remove them mechanically?

tabetha

Your best bet is to put the piston back in, then recoonect up to hydraulics and let pedal pressure pop them out, leave just loose not over disc!!.
I have recently done mine with new seals for less than £30 the pair, but had to have two new pistons(£9each) as were damaged.
You will find that they will easily come almost out with the fluid pressure and using a "G" clamp or two you can limit the travel so they are all nearly out so you have something to grip with a decent unworn set of moles grips, or you could use a windout, you stick it in the centre of the piston and just turn it it grips harder the insides as you turn it so will have no problem.
If not just turn with the mole grips, I had to vandalise two of mine to get them out, but patience and perseverance is the name here.
I got my stuff from BIGGRED.CO.UK, they are around £120 a pair recon if you did not want to do them.
tabetha

cosrep

I got the rebuild kit from biggred already, if I need them where can I get new pistons?

tabetha

BIGGRED, top man he is too, used to do them in SS but beleive he uses a different material now.
tabetha

foreigneRS

hold the loose piston in with a g-clamp

don't soak the seals in wd40 - they will expand and not fit anymore

krisberic

I got my front calipers from these and are excellent.

cosrep

Ok went out and bought a second set of G clamps and managed to get all the pistons out of caliper no. 1
Moving on to caliper no.2 I noticed that one of the four bolts that holds the caliper together has been chewed at some point in the past - no hope of getting a spanner/socket at it so I drilled the head off only to discover the remaining "stud" is jammed solid in one half of the caliper body. The usual methods of a little heat and WD40 have failed. I dont want to put too much brute force on it in case the remaining stud shears off leaving the treaded portion stuck in the caliper. Any ideas?

tabetha

Put half the caliper in bench vice and TWIST as it wil loosen easier this way than straight pulling.
SOAK in DIESEL FUEL first as this will help to loosen.
You will find that as you twist the half it wil either loosen or undo bolt, making sure you turn in the dirtection bolt would need to to undo!!, then it would just need pressing out if still stubborn.
At least if it undoes and bolt is still jammed you have something solid to put in vice while you can wiggle caliper each way while bolt is held firmly in vice, heat would help but not enough from a DIY blow torch as it disipates the heat too quickly to be effective.
tabetha

cosrep

This is what the caliper looks like at the moment, I have a methlyacetalene torch the flame burns at over 1000 celcius but I would be afraid of doing damage to the casting if I applied the heat too long.

foreigneRS

nasty

tabetha

Does look nasty, but what alternative is there ?
tabetha