How do free a seized caliper piston ?

[seeby]

I am fitting new pads ,but one of the rear caliper pistons will not push back .Whats the easiest way to free it ?

[magpie215]

some rear pistons need to be wound back is it one of these???

[seeby]

Ah yes that did cross my mind (but then I thought I was being stupid)The piston is off a Ford Sierra and on my TVR.It has a smooth face with 4 "v" shaped grooves in it .Would that be a screw back jobby ?

[magpie215]

yep iirc the 4 Vs are for tool engagement to wind it back in

[Matt Seabrook]

Don't want it p**s on your chips but if you are tackling a brake job and don't know the correct way of fitting the pads do you think you should be doing it? I'm not saying take it to a garage but don't you have a friend that knows what they are doing and could help?

[seeby]

I have a best mate who is a mechanic but as he was entertaining his new lady friend I didn't want to spoil his fun by phoning him . I did basicly know what I was doing but just wanted a second opinion.

[Matt Seabrook]

Ok, I have just seen too many DIY jobs that went horribly wrong and have been asked to pick up the pieces. Hopefully yours has gone ok.

[Viperz888]

Sierra rears need a windy tool. One spins clockwise and the other anti clock wise to push them in, but I can't remember which side is which.

If you're lucky, a pair of needle nose pliers might get them moving, otherwise you'll need the tool. Can get universal ones quite cheap, or a full kit that will do many different types, but they cost more.

[seeby]

Thanks for advice all,once it was determined they are wind backs,I used a grinder disc removing tool to wind the pistons back .

[texaxile]

(kind of) on topic:

When unseizing calipers, re lubricate & Re assemble using Silicon grease or Copperslip?.

[Dave Brand]

texaxile said:

(kind of) on topic:

When unseizing calipers, re lubricate & Re assemble using Silicon grease or Copperslip?.

If it's going to be in contact with any of the rubber parts use only brake fluid or red rubber grease. Petroleum-based products (including some brake cleaners!) can damage seals.