brake calipers

exploited · Post by **exploited** » Sun Feb 06, 2005 10:35 pm

have just stripped brakes to clean around pistons
the problem i have is that the pistons are not returning back in without a great amount of force ,should they return easy
thanks in advance

Stormin Ben · Post by **Stormin Ben** » Mon Feb 07, 2005 11:26 am

Depends how cruddy they have gotten but generally, no

When I clean mine they can be a bit stiff the first few times of pumping (ooh-err!!) but after that they push in by hand.

Make sure you are pushing them in square coz they WILL jam if they aren't
If they are still really stiff after you've pumped out, cleaned and pushed back in a few times it may be that you've got crap in behind the piston seals which is pushing them out slightly and jamming the piston.
To remedy that you'll need to remove the caliper and remove the piston fully

Ben

Pete.L · Post by **Pete.L** » Mon Feb 07, 2005 2:30 pm

Hi Exploited

When you say you have stripped the brakes how far have you gone?
Have you drained the brake fluid and removed the pistons or have you just taken the calipers off the bike so you have better acess to clean them.
If you have drained the fluid I agree with Ben if you just pumped the pistons out a bit to clean the crud off and have left the fluid in the system you have to open the reservoir on the handle bar and yes they will be stiff to push back in

Pete.l

exploited · Post by **exploited** » Mon Feb 07, 2005 7:57 pm

thanks for your help
i did not drain the brake fluid
can you tell when pulling the brakes should the 4 pistons come out at the same time, and when i was doing this should i have removed the
reservoir cap to release the pressure

delmeekc · Post by **delmeekc** » Mon Feb 07, 2005 9:13 pm

I'm sorry but you obviously are really not that sure of what you are doing and I would find somebody who does know. Lets face it you are messing with the one thing that's going to save your life (like stoping quickly from 145mph) and if you wombles it up then don't even think about what could happen.

The only advice I have it "STOP" and if you have to give it to a dealer.

Del (this reply is not sarcastic but just some sensible advice)

exploited · Post by **exploited** » Tue Feb 08, 2005 9:53 pm

just thought i would give a response to your reply
as a law abiding citizen i would not be doing over 70
and now i can see why you need a helmet that size

Stormin Ben · Post by **Stormin Ben** » Tue Feb 08, 2005 10:05 pm

exploited wrote:thanks for your help
i did not drain the brake fluid
can you tell when pulling the brakes should the 4 pistons come out at the same time, and when i was doing this should i have removed the
reservoir cap to release the pressure

Whenever I've done it (usually at least twice a year) I don't release the resevoir cap (coz I'm not changing the capacity of the system, eg when putting new pads in)
And yes, the first time only one of the pistons moves

Work on only one caliper at a time
Pump ou the loosest piston
clean it up, push it back, clean it up push it back etc
Then prevent that one moving (old brake pads wedged suitably or bits of wood are ideal) and pump again.
The next loosest one will move out
Clean, push back etc etc and wedge it.
Repeat for all 4 pistons, you will then find that all 4 more or less come out together eventually (takes me approx 45 mins per caliper)
Then replace the caliper and move onto the other one

Finally make sure both calipers are tight and don't forget to pump out the pistons to meet the disks BEFORE you ride off

Ben

exploited · Post by **exploited** » Wed Feb 09, 2005 9:25 pm

finished doing brakes ,working fine now

thanks for your help