Hi All,

I need to replace the seals in my M16 brake callipers and am having trouble getting the pistons out.

Just wondered if there was a miracle tool or puller that would withdraw the little darlings.


Found loads that will push them in but thats not the problem as 13 years ago when I bought them
I pushed the pistons in and fitted new pads.
If one of you lot had told me IVA wasn't until 2015 I'd have left the old ones in.

Cheers
Paul G

Removing a bleed nipple and blowing with compressed air has worked for me in the past.

I have had little success with using a compressor. However, connecting up to a mater cylinder (mounted in a vice ) has worked usually. Also heard of using a grease gun. Some callipers I have just given up on, but they are usually VERY rusty, been on a car in a field for 20 years.....
I suspect yours just need a good nudge to get them going.

What Clifty says, or a car if available.
You'll find one will move easier so you may have to clamp that one fully in to get the stubborn one
to start to move. Then once that one is a fair way out clamp that one and let the other piston move.
Split the caliber and with a bit of fiddling to block some ports compressed air should get them the last bit.

I got mine out by using a battery tyre inflator. One on each caliper was stuck solid, so loosened it by hitting it with a hammer and steel bar. I'm replacing the Pistons and seals so this may not be ideal.

Just in case you're not aware of them both Draper and Sealey do honing stone sets which mean you can achieve an optimum finish inside the bores.
IIRC 25-57mm stones are the ones you require.
HTH.
Cheers, Pewe10

Unless you used WD40 or similar when you fitted the seals and pistons (in which case the seals are toast) leave it until they are fitted to the car.

No need hone the bores unlike a wheel cylinder the finish bore of the caliper isn't critial.

I had the same problem, bought a 3 legged puller, had to grind a little to grip the piston sufficiently, though it worked.

We used to have something similar to this when I worked in a garage. They grip the inside of the piston so you can turn them to free them up.

Commpressed air can be used in conjunction with this for stubborn pistons.

http://www.amazon.co.uk/JMP-brake-piston-removal-pliers/dp/B0054QFKN2/ref=sr_1_6?ie=UTF8&qid=1425721580&sr=8-6&keywords=Brake+Piston+Remov al+Pliers

Paul the easy way to shift stuck Pistons is to leave the calliper attached to the brake hose, remove pads and clamp one piston using a g clamp or similar, get some one to slowly pump the brake pedal whilst watching the unclamp piston , you may have to press the "moving" piston in a few times before it frees off , once free repeat with remaining Pistons. If there is any signs of pickling on the Pistons it may be cheaper/ easier to fit reconditioned calipers . If the caliper is still attached DO NOT use compressed air through the bleed nipple, you run the risk of brake fluid all over the place and of damaging the master cylinder.

As mentioned further up, compressed air is my first option, next is a grease gun. I have a bleed nipple with a grease nipple threaded into it specifically for the job, they always come out with that

Ian

Thanks for all the replies everyone.


The callipers were already removed from the car so that sort of removes hydraulics from the equation.
Fluid is also missing as I have already replaced the rear slave cylinders.

Air didn't seem to move anything and I don't possess a grease gun…….



but I do have a lathe.

I cut a hole with a stepped edge in a plate so that it fitted the dust cover recess then cut this in half.
A plate to hold the two half's together, a piece of angle on the outside of the calliper, and a G clamp either side.

I've cleaned it up and I'm now off to assemble with the new seals and that's one side done.

The other side should go quicker,

groan, then it's bleed time, another groan.

Cheers,
Paul G


Description

removal aid

Second side done.

It's bleedin' Sunday tomorrow.


Paul G

I never could get my brakes bled properly - in the end I took them to a local garage as I needed to get the tracking done anyway. Ten minutes later the brakes were done and many times better than I'd ever managed. No special tools or whatever - just years of experience.

I borrowed a Sealey vacuum bleeder from Duncan (the chap with the baby Austin) in 2004.

He said to let him have it back when I finish with it.


Cheers
Paul G