Stock Brake Calipers

Message

YPVS KIWI · #1 Post by **YPVS KIWI** » Wed May 14, 2008 6:37 am

Couple of dumb questions from the newb:

Do both pistons come out of the calipers - if so how do you get the second one out?

Having dismantled the front LH caliper I decided to check the manual to find two of the bolts i removed are labeled "do not remove"

Oopps - can anyone tel me why they should not be removed, there is a couple of seals around the cross over ports between the caliper halves thats all.

Help much appreciated.

Gary B · #2 Post by **Gary B** » Wed May 14, 2008 7:56 am

The usual way I pop brake pistons out is with compressed air, best to wrap it all in a cloth to avoid flying brake fluid and parts, safety glasses would be wise as well. Might be corroded and tight (steel piston/magnesium alloy caliper). Would soak it in penetrating oil if it does not want to move.

Guess they don't want us to split them as it is a precision ground face but this kind of joint is common in aircraft hydraulic components and do get split for servicing (my basic trade).

Strictly the seals should not be re-used, they are not shown in the parts catalogue though. Any replacements would have to be brake fluid compatible (a lot of '0' rings are not and they melt).

I have got three calipers off of the other bike that will need this doing to, the rear caliper on my running bike is quite 'rough' and the front pistons are a bit 'sticky' as well.

British winters with salt on the roads did not help the situation.

Let us know how you get on.

Cheers

Gary

YPVS KIWI · #3 Post by **YPVS KIWI** » Sun May 18, 2008 2:45 am

Thanks Gary - the seals are flat rubber - will try the local seal shop for something brake fluid compatible. All three RH pistons came out using the mater cylinder to pump them out. Will take them to the workshop over next week or two and try the compressed air trick to get the LH piston out - let you know.

Cheers.

jackson.40 · #4 Post by **jackson.40** » Thu May 29, 2008 8:20 am

I have been told of a better seal than the one i was using on my calipers.As you know Yamaha do not list the seal and i was using a suzuki part which was part no. 69107-34200 .I have now ordered a Kawaski seal which is part no. 43049 1004.I pick it up next week and will post some photos up.Cheers Steve