AARRGGHH Front Brake sticking

[phonesurgeon]

Guys please help....

Front brake is sticking, i ve taken it off cleaned greased and put it back on..... same problem!

So opened up the brake fluid reservoir, and the fluid was brown.... so i thought i'd flush it....

Half hour later the fluid was that greenish colour... all done I thought.... wrong same problem!

Now i am at my wits ends and still none the wiser... with the front brake still sticking!

Please help!

[stisma]

Sounds like...... pistons are sticking (not retracting).
See if you can push back on the pistons.
Cast aluminum tends to go bad with time, oil, moisture.
If you are lucky, good cleaning of the pistons and caliper cylinders will sufice.

[phonesurgeon]

Cheers stisma, i ve just reached the same conclusion, seized piston... so while i am there i will strip and overhaul the whole unit!

[SJL]

Hi Phonesurgeon,
Trawling through Ebay, saw this and thought of you....

http://www.ebay.co.uk/itm/Aprilia-Pe...item20bcddfdca

Front brake kit, £22 plus £6 delivery,
Cheers,
Ste

[mitcher9]

Hi Phonesurgeon
Once you have removed the pistons, dust seals and fluid seals have a good clean in the grooves where these seals sit. I find it is usually corrosion/dirt in this area that causes the seals to grip the pistons too tightly. If that does not work I would suspect the brake hose. I had this problem with my back brake having cleaned and checked everything multiple times I replaced the hose which was acting as a one way valve. One way to establish what is the problems is that when the brake sticks, gently release and then tighten the bleed nipple to see if fluid comes out quickly and the caliper magically frees up. If that happens the best bet is the hose. If loosening and tightening the bleed nipple makes no difference then it is probably dirt/corrosion behind the seals.
Cheers
Robert

[chrism15]

brake caliper revision kit

pistons are sticking and then not retracting as above ^^

strip it down, fit new seals and a bit of grease - might be worth buying a can of high temp spray paint, red? and go over the caliper before re-fitting - really gives them a new look

[phonesurgeon]

Update....

Brakes now working as they should... complete strip and clean... changed seals... both front and back.