Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[tunnie]

In process of doing father T's rear pads, had to take caliper bracket off as pads stuck solid.

Inner pad had fair bit of meat on it, outer pad was down to the metal. Plus fact inner caliper pushed in nicely, the outer is stuck fast, think its seized up. I cannot get it to budge no matter how many swear words I use!

Any ideas on how to free it off?

[Andy B]

....
Any ideas on how to free it off?

I've removed stuck caliper pistons by removing the brake pipe, replacing it with a grease nipple & used a grease gun. BE CAREFULL OF WHERE YOUR FINGERS ARE. 
If you want to try to push it back in again & have another go with it all still on the car, how about a G clamp  :-/

[Entwood]

In process of doing father T's rear pads, had to take caliper bracket off as pads stuck solid.

Inner pad had fair bit of meat on it, outer pad was down to the metal. Plus fact inner caliper pushed in nicely, the outer is stuck fast, think its seized up. I cannot get it to budge no matter how many swear words I use!

Any ideas on how to free it off?

Loads of plusgas around the piston and leave to soak for a while. Place a block of wood across the piston to ensure even forces.
Release the bleed nipple to allow fluid to escape.
Either LARGE plumbers grips or a good G clamp and force the piston IN to start with.

The corrosion forms a "lip" on the piston which you are trying to break. Once broken it should pump out using the brake pedal. depending on the state of the surface it might need a new piston.

[tunnie]

Think a G clamp is way forward, mine are not man enough though. Think I might go buy one of these:

http://m.screwfix.com/details.htm?id=19451

Says it's for wood though :/

[tunnie]

Cheers entwood. Think I should finally buy some plusgas!

[2woody]

I wouldn't use plusgas or grease as it'll rot the seal.

.... and using the g-clamp will foce the rusty part of the piston past the seal, damaging it

either :-

use compressed air to blow the piston out, or

re-fit the caliper and bleed it, but don't fit the pad on the stuck piston side. A good few pedal applications will force the piston out of it's bore, allowing you to clean it up and re-fit

[Jimbob]

I use one of these

http://www.machinemart.co.uk/shop/product/details/cht268-disc-brake-piston-spreader

nice even pressure

[tunnie]

Cheers all

Jimbob - that looks perfect for the job, I'll have to get me on of those for next time. Closest machine mart is Coventry

Think I'll release the fluid. The solid brake pipe bolt into top of the caliper, that should just be loosed to let fluid out I assume? Won't need to come all the way out?

Is it worth clamping the brake line further on, with mole grips?

[Kevin Wood]

Cheers all

Jimbob - that looks perfect for the job, I'll have to get me on of those for next time. Closest machine mart is Coventry

Think I'll release the fluid. The solid brake pipe bolt into top of the caliper, that should just be loosed to let fluid out I assume? Won't need to come all the way out?

Is it worth clamping the brake line further on, with mole grips?

Releasing the fluid won't help. You've pushed one piston in, so the fluid is not what's stopping the other.

What you need to do is take the piston out and find out why it's stuck. For this you need to proceed as 2Woody suggests and pump the piston out using the pressure of the brake fluid behind it.

Kevin

[tunnie]

Thanks Kev, so I'm not to release any fluid? Im a biit confused as woody said to bleed it?

Just refit the caliper and pump it out using brake pedal?

[2woody]

I said bleed it because I assumed that the caliper was already off the car.

[Kevin Wood]

Thanks Kev, so I'm not to release any fluid? Im a biit confused as woody said to bleed it?

Just refit the caliper and pump it out using brake pedal?

Sorry - crossed lines. If you've disconnected the hydraulic circuit you need to connect it back up and give it a quick bleed so you've got a firm pedal again, then remove the pad from the troublesome side and fit an old pad in the OK side. Put a pan under the caliper to catch the fluid that'll come out then squeeze the brake pedal until the cylinder pops out.

You do risk getting air into the ABS pump by doing it this way as some air may be drawn in as you release the pedal if the piston pops out all the way. Guessing a Tech2's not far away if that happens, though.

Failing that, get the caliper on the bench and strip it manually.

Kevin

[tunnie]

Sorry I should have explained myself better. The two bolts which mount the caliper bracket have been removed. But it's still attached to the car, as I have not removed the brake pipe feed.

Caliper bracket is now back on the car, with good side having pad refitted. Outer caliper has not had pad refitted. Do I pump the brake to push the piston out? (as good side will be held by pad)

[Kevin Wood]

Caliper bracket is now back on the car, with good side having pad refitted. Outer caliper has not had pad refitted. Do I pump the brake to push the piston out? (as good side will be held by pad)

Yep, that's the general idea.

Go gently at first. Don't want to make any more of a mess than is required.

[CaptainZok]

Caliper bracket is now back on the car, with good side having pad refitted. Outer caliper has not had pad refitted. Do I pump the brake to push the piston out? (as good side will be held by pad)

Yep, that's the general idea.

Go gently at first. Don't want to make any more of a mess than is required.

Get the short shouty bloke round to drink tea and offer encouragement.