12 replies to this topic

[stormintrooper]

i have 8.4 disc set up and i believe one of the pistons is sticking as when i replaced the pads i noticed i couldnt push it in by much, so was wondering what do i need and how i i solve this unfortunate problem

Edited by stormintrooper, 20 May 2010 - 05:14 PM.

[wassupcrew]

what you need to do is get a caliper seal kit, minispares part number GRK5008. take the caliper off and remove the pistons by pressing the brake pedal, they should pop out easily. remove the old seals and replace with the new ones. clean up the pistons first before replacing the seals making sure all the dirt is out of the grooves the seals sit in. if there is any pitting on the pistons at all it is best to replace them aswell. get stainless steel ones as they will last longer

[Stevee]

what you need to do is get a caliper seal kit, minispares part number GRK5008. take the caliper off and remove the pistons by pressing the brake pedal, they should pop out easily. remove the old seals and replace with the new ones. clean up the pistons first before replacing the seals making sure all the dirt is out of the grooves the seals sit in. if there is any pitting on the pistons at all it is best to replace them aswell. get stainless steel ones as they will last longer

I Advise AS A Mechanic On Not Doing That

80% of the time the pistons will leak brake fluid And let air in making the brake pedal like a sponge

PERSONAL! I State Personal Id Do

1. Buy New Caliper
Or
2. Remove Caliper Off, use a piston pusher and push piston back, refit to car, pump pedal so piston moves out, and repeat, still it stops sticking,
(keep the caliper on the brake hose though)

I have done this on a Rover 200 and its still going well

But thats what id do Personal

[Cooperman]

Wait till you try to fit the outer wiper seals! Possibly the worst job on a Mini.

[stormintrooper]

outer wiper seals?

[Stevee]

outer wiper seals?

http://www.restorati...piston_leak.JPG

The Red Arrow

(that what can also happen when you buy them seal kits)

[bmcecosse]

It is quite a job to fit new pistons/seals to the calipers. But it can be done - on the bench - not on the car! You may want to consider reconditioned calipers if you are not confident.............

[stormintrooper]

well its only the one side thats buggered...can you get away with just one calliper?

[Stevee]

TIll an MOT yes

But It Fail On Braking Efficentce

Mine failed on it!! im running drums all round atm

[stormintrooper]

no i meant is replacing just the one calliper (i.e. leaving the one thats ok as it is) ok to do?

[Stevee]

Oh yeah thats perfectly fine

but i will advise you change pads again if you do a caliper

better safe than sorry

[RWDwanted]

what you need to do is get a caliper seal kit, minispares part number GRK5008. take the caliper off and remove the pistons by pressing the brake pedal, they should pop out easily. remove the old seals and replace with the new ones. clean up the pistons first before replacing the seals making sure all the dirt is out of the grooves the seals sit in. if there is any pitting on the pistons at all it is best to replace them aswell. get stainless steel ones as they will last longer

I Advise AS A Mechanic On Not Doing That

80% of the time the pistons will leak brake fluid And let air in making the brake pedal like a sponge

Is this the general consensus?

Is it not worth fitting stainless steel pistons and new sills?

Will the caliper never be as good/safe as it was with the original pistons and seals?

[MRA]

We remanufacture callipers using only stainless steel pistons and obviously new seal kits, there is nothing wrong with changing the internal components, as long as it is done correctly, always always use a specific rubber grease as some other greases can and do destroy rubber

If done carefully then you have no issues with safety.

You can rebuild them without splitting the caliper halves, however we just strip them out completely and send them off for plating.

I cannot comment on other makes and types of caliper other than the four common ones and our own calipers used on the Classic Mini.