940: outer caliper piston seized

[mschultz373]

I went to do the brakes and rotors on my 940 project car today and seem to have run into seized outer caliper pistons on both rear brakes. the PO had said the brakes were eating into the rotors and that's exactly what appears to be the case - there was no pad left on the outer brake pads for either rear wheel, causing the metal of the caliper to eat at the rotors. i have a caliper piston retractor tool but cannot get the outer pistons on either caliper to retract.

is there a way to rebuild them and still use these calipers and solve this issue, or is it easier to order re-manufactured ones and replace them?

[white855T]

Order remanufactured ones. I ordered mine from rockauto centric brand.

[2manyturbos]

^^

Either buy yourself a set of used calipers in good condition or get your self a set of rebuilt calipers. The problem with the rebuilt calipers is the quality is so questionable these days. That includes Centric brand rebuilds.

[mschultz373]

thanks yall. best practice to replace all calipers or doesn't matter? if quality of remanufactured ones is low and front ones look fine i'll just roll with em.

EDIT: These are the centric ones? https://www.rockauto.com/en/moreinfo...89088&jsn=1342

[adamdrives]

They are simple to rebuild with a kit from Rockauto. I did so on my 240 on all 4 corners. All 4 had a considerable amount of mineral deposit/debris in them. I used a wire wheel on a die grinder to clean out the bores. I’d rather that than gamble on a used set.

[Khrrck]

Make sure to replace the hoses on each corner too (if old), that's where most of the crud comes from.

[G-Tech 940]

Easy as anything to rebuild calipers.

just need an air compressor, a block of wood if it's dual piston, a flathead screwdriver, and some assembly fluid. Maybe a larger bar to rock the piston in if your screwdriver cant do it.

rebuild kits should be easy to find on ebay, except for pistons. Make sure you don't mess up the original pistons. Pretty sure they're steel and not phenolic.

I'd tear down the originals (remove a bleeder and blast the hole with an air compressor, use a wood block if theres 2 pistons) before ordering the rebuild kit, just in case the stuck piston is toast. 99% should be alright though, unless the boot has been gone for a while and its super rusted and pitted too much to save.

[mschultz373]

putting the new calipers and brakes in, but I am having an issue with the metal brackets. I cannot seem to get the bottom part of the bracket to sit on the guide pin - it wants to sit down in the recess of the caliper as shown.



these brackets came with the calipers so I figure they should work and I am just dong something wrong?

[hiperfauto]

The anti-rattle clip is on backwards. Flip it over.

[mschultz373]

wow, I didn't even think of that. Thanks for being gentle with me and not flaming me for such a n00b question.

someone once told me - if everything goes right, you don't learn as much. always learning....