BlueSmoke

As above really. I put new discs and pads on the front of the MR2 at the weekend, and they stop good, but something wasn't quite right. This morning I realised what, as I pulled up and found smoke coming from the driver's side front wheel

When I changed the brakes I had real trouble getting this piston wound back in. Had to use a G clamp and a lot of blood, sweat and tears. In my relative inexperience I actually thought once I had got the piston back in, it would unseize.

I guess I was wrong

I don't fancy having to get a new caliper as I don't wanna take the old one off, the nut on it doesn't look like it'll want to play.

COMEDY DAN

Yes.

BlueSmoke

Lol straight to the point Dan.

How do I sort it? Do I have to get something down the sides of the piston and in between the piston and the rubber at the top, and if so, what?

COMEDY DAN

Take it off and soak over night in Brake cleaner.

Then get hold of a caliper winding tool and gently wind in a nudge then back out, in then back out and so on making gentle progress.

Once the piston is freed up, you need to buy a seal repair kit from your local brake supplier which is very simple to fit.

Seal repair kits are usualy around Ł15.
Tin of brake cleaner around Ł3.99
Doggers labour time, PRICLESS.

DONE.

BlueSmoke

So I take the piston itself out and clean it or just dunk the whole caliper in brake cleaner?

Cheers dudeson.

tabetha

It would be a lot eaier to use the pedal pressure to pump piston out then clean it up and renew the seals, take out pads first and just pump, it will come out, might as well do other side as well, as it will likely be as bad, leave alone though and do one at a time, easier.
tabetha
ps BIGGRED do seals cheap 01905 428793.

bud-weis

yeah as above....i had an RS Turbo caliper seize once, removed the pads and then pumped the pedal to pop the piston out...there was a fair bit of surface rust on the piston, so i used some wet and dry paper and just cleaned it off and then slid it back in,worked fine after that, ideally i'd have changed the seals etc, but it was only a bean tin

Stu.H

bud-weis

BlueSmoke

Should I be looking to remove the piston fully? Or just clean what's exposed?

bud-weis

i'd personally remove it fully and then clean as much as possible including the bore...but be prepared for losing loads of fluid and taking an age to bleed up once it's back together

BlueSmoke

Bah, I hope I have enough fluid left from the bleed on Saturday.... :s

bud-weis

just clamp the brake lines then to minimize the loss

davidnormanuk

Pump the piston until it pops out putting a cloth or something over it to stop it bouncing anywhere. Inspect the piston for pitting/damage etc. If there is damage below where the selas sit on the piston you need a complete kit. Take the seals out being careful not to damage them. Clean around where the seals sit as that'll be whats causing your calipers to bind as water gets being the seals causing the aluminium to corrode and it pushes the seals out. Put the seals back in with a coating of rubber grease. Coat your piston with rubber grease and reassemble. I have done this many times with cars and bikes and never had a problem providing you check the parts over.

davidnormanuk

Also check you havn't warped the disk.