Has anyone had same prob? Any advice please?

The front o/s brake caliper was making a creaking noise, turned out to be a sticking piston so i took pads out and eased piston in and out a dozen times sprayed a bit of WD40 and it was fine for about three weeks.

Happened again, same piston so i did the same and also replaced pads as the sticking piston was making the pad wear more at the top. It was fine for about 2/3 weeks again.

Now its sticking again. Does anyone know what might cause it, could it be a ridge in the barrel? Would a piston seal kit cure it, and are they reliable enough and easy to fit? Do i need a new caliper and should i replace them both or just one side?

Cheers,

Either the seals are swollen/damaged or there's corrosion behind the seals.

A new seal kit should cure the problem. Make sure you clean any crap out of the seal groove before fitting the new seals. Lubricate them with either brake fluid or proper rubber grease when putting the calipers back together and make sure the outer dust cover is not split as I'm not sure wether these come with the seal kits

 

It's a very easy job to do and a false economy to do just one side.

 

Hope that helps

 

Robin

IIRC WD40 knackers hydrualic seals, causes them to go sticky. You deffinatly need a seal kit, if the pistoncleans up OK it should clear the problem. The piston is unlikely to have a ridge worn in it inless the seal was contaminated with grease. Also bleed the system well to purge any WD40. I don't know it's boiling point but I bet its less then brake fluid and if there is any left in there when the brakes get hot it will boil and reduce the pressure to that brake and the diagonally oposite one significantly increasing your stopping distance.

 

Kits are easy enough to fit, the difficult bit is getting a decent bleed afterwards. Make sure that when you remove the old seals you dont scratch the sealing surface of the calliper body or the piston. Use a solvent to clean them up, again make sure it's all gone before assembling and bleeding the circuit.

 

NB if there is any corrosion or scoring inside the caliper or on the surface of the piston then you need a new calliper. You can change callipers one at a time but if the disc or pads are knackered on one side then change the whole axle set.

just to add to the above - any light scoring/pitting can be removed with some fine wet & dry with a little brake fluid on

Had same trouble. ended up with breakes binding and me cooking the fronts and warping another set of rotors.

 

Solution, seal kit, and fitted springs to push pistons back, have been great ever since.

sounds like a good excuse to upgrade the brakes to me!!

 

Kirbz

You might find that the piston has some rust pitting on it as well but cant see it till the piston is right out. New pistons are about £25 each.

Cheers guys very helpfull,

i've ordered a seal kit and one new piston just incase from Mjp,

they're coming from Amsterdam lol.

I've never heard of springs to push pistons back before tho, wouldnt that give you alot of pedal travel?

The discs have been upgraded, they're cross drilled and the brakes feel very good even with sticking piston. Out of curiosity, anyone know what sort of cost new calipers are , or upgraded ones?

 

Cheers,