Rebuilding 4-pot calipers

[bigbeard]

I've got a 400SE with the AP Lockheed 4 pot calipers on the front.

One of the pistons was siezed so I took off both calipers to have a good look at them. All the pistons are corroded a bit on the bit that sticks out from the caliper. The rubber seals all seem fine.

The plan is to replace the pistons. Is it worth replacing the rubbers as well?

I've never reconned callipers before. I can get the pistons out using a foot pump and back in with G clamps. Any tips on how get the rubbers out and the new ones in without damaging anything? Is there anything I should watch out for or things that you must do while doing this?

Also, I've got my local motor factors hunting for replacement pistons. If he doesn't find any, does anyone know anywhere which sells rebuild kits for these calipers?

cheers
Ian

[shpub]

It's covered in the bible. The pistons are like rocking horse doo doo (I'm pretty sure that they are the same as Princess ones) and the last time I got some they were £18 each. +VAT +delivery. Yes they will need new rubber seals and new clips. Get Lucas/AP lockheed ones as the others are not very good and will start to leak.
Worth checking the bores for scoring before getting pistons etc. If they are, it's new calliper time!

[bigbeard]

Cheers for the response steve. I'll have to see what the local motor factor comes up with!

An alternative I suppose is to buy some already reconditioned calipers if thats possible, or replace with new ones - does anyone make any that would fit the standard discs and mounting points?

[my 350i]

New or recon 4 pot ap calipers are not available off the shelf or to order. AP wil however recodition your own units for you, I was quoted around £75 each, inc new pistons, seals, delivery and vat. This can normally be aranged through a local friendly motor factor.
Dave

[streaky]

Always replace all seals on brakes when servicing/reconditioning ... your life is worth at least the few "pence" they cost.

A tip I was given many moons agao was to soak the piston seals in brake fluid before fitting.

Streaky

[bigbeard]

The motor factor has got back to me :

They can supply the rebuild kits (new pistons and seals) for £69 plus vat for each caliper. Alternatively they can get them reconditioned (fully cleaned and painted with new seals and pistons) for £70 plus vat!

Seems like I might as well get them reconditioned, rather than do it myself!

[rev-erend]

Tough choice that one ..