metro 4 pot piston seal replacement
Turbo Mini Forums

Okay so... i replaced the metro 4 pot seals that i have with some i brought from mini spares... and the pisons are now leaking from around the seals..

is there some sort of special method that is needed when replacing these seals? i put the middle seal in, folowed by the top one and the metal locking ring, then put the piston in.

cant seem to find much in the way of advise about replacing these seals.

any comments would be appriciated :)

Absolute cleanliness is essential for this job'

I would have fitted the piston before the outer dust seals and then a smear of brake fluid or rubber grease to ease the fitting of both the piston and the seals.

I,m afraid you will have to strip the calipers out again to see whether the seals are damaged or displaced.

I assume the pistons had perfect surfaces because the slightest mark on them will usually cause trouble.

I found that most of the calipers i've stripped with chrome plated pistons, the chrome is a bit crusty. Crusty pistons wont seal vwry well

the pistons are all in good condition, found the issue.. which must have been my fault but i didnt force anything in and as previously suggested i used brake fluid to lubricate the pistons for assembly..

basically small shavings of the inner seal have been ripped off the seal causing the obvious leak... new seals ordered. although not entirely sure how i can fit them any differently to how i have previously ahha

red rubber grease, and ensure the seals are fitted in the correct direction...yes they are directional.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

this could well be the problem... didnt realise they were directional.. my dad said they could have a taper on? is that the case? live and learn i guess!!

When i fitted mine (albeit 2 pots) i bought brand new stainless pistons too and it was fine except i ballsed up a metal ring and had to buy another, never had a leak from those.

the pistons are in very good condition so its not those, have brought new seals and will try again, ensuring that the seals are the right way about

just take your time and loads of lube

Done now needs redoing lol

That,s good advice for more than one situation.

hahah ill take note of this advise ,

stevie, which way are the seals meant to go in? you say they are directional but they look pretty semetrical to me..

make sure its the correct grease for the seals, its usually red, but we had turquoise stuff in work, but aye, normal grease will knacker the seals and react with brake fluid.

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

On 20th Feb, 2014 jonnyBMX said:
hahah ill take note of this advise ,

stevie, which way are the seals meant to go in? you say they are directional but they look pretty semetrical to me..

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will