Hi Guys,
Can anyone help with advice on freeing up a sticking brake caliper piston? I have just changed the front disks and pads and found the near side brake assembly has a one of its caliper pistons sticking. I was able to release it; with the pads removed, and then pumping the brake pedal to expel the piston and then used a "G" clamp to depress it back into its housing. However, having re-assembled everything and taken the Bongo on a quick road test, it seems the piston is still sticking in the out position and, therefore, is causing a slight application of the brake - not good. Any advice would be much appreciated.
Cheers
FRONT BRAKE CALIPER PISTON
Moderators: Doone, westonwarrior
FRONT BRAKE CALIPER PISTON
Home is where you park it..... 
-
mikeonb4c
- Supreme Being
- Posts: 22877
- Joined: Sun Nov 05, 2006 10:49 pm
- Location: Living with Mango Bongo in the North West but with a tendency to roam
- Contact:
Re: FRONT BRAKE CALIPER PISTON
BF member has front one i think for sale on here as he's selling up. Advert appeared on here a day or two ago. Could pm him?Stargazer wrote:Hi Guys,
Can anyone help with advice on freeing up a sticking brake caliper piston? I have just changed the front disks and pads and found the near side brake assembly has a one of its caliper pistons sticking. I was able to release it; with the pads removed, and then pumping the brake pedal to expel the piston and then used a "G" clamp to depress it back into its housing. However, having re-assembled everything and taken the Bongo on a quick road test, it seems the piston is still sticking in the out position and, therefore, is causing a slight application of the brake - not good. Any advice would be much appreciated.
Cheers
Re: FRONT BRAKE CALIPER PISTON
Assuming your caliper sliders are free and providing the piston itself is clean and not rusted. The bit that keeps the piston out thereby compensating for pad wear is the seal itself. Think of a wiper blade action.
You may have done this but remove the piston again check the lip of the seal for damage if it is then go for another caliper, else, wipe the lip of the seal with brake fluid and also the piston, refit the piston into the caliper ensuring the bleed nipple is open, push piston as far back as you can get it ensuring it goes in square using gentle but firm pressure,use an old pad across the piston this will help you align it,refill caliper with fluid and get someone to very slowly depress the brake pedal let the piston move out as far as it can without coming out, wipe the outside of the piston again with brake fluid and with the bleed nipple open gently but firmly push the piston back to its lowest position do this a few times then refit outer gaiter refit caliper and bleed out entire system.
You may have done this but remove the piston again check the lip of the seal for damage if it is then go for another caliper, else, wipe the lip of the seal with brake fluid and also the piston, refit the piston into the caliper ensuring the bleed nipple is open, push piston as far back as you can get it ensuring it goes in square using gentle but firm pressure,use an old pad across the piston this will help you align it,refill caliper with fluid and get someone to very slowly depress the brake pedal let the piston move out as far as it can without coming out, wipe the outside of the piston again with brake fluid and with the bleed nipple open gently but firmly push the piston back to its lowest position do this a few times then refit outer gaiter refit caliper and bleed out entire system.
Re: FRONT BRAKE CALIPER PISTON
It's always good to use red brake grease on the seals before putting the piston back in.