Topic: Front brake questions

[xfactor]

So I dissembled my front brake and removed the piston to clean it, now it wont go back in. Should I add more brake fluid to it and then try to push it back in, or should I wait to add fluid and keep trying to get it in?


Thanks,
Croix

[Gordon]

Lube the piston and the seal with some brake fluid and it should slide in easily. 

[xfactor]

Lube the piston and the seal with some brake fluid and it should slide in easily. 

Thanks I will give her a try now

[Gordon]

Before you do that (or is it too late?), you should remove the seal while you have everything apart and clean out the groove it lives in.  Crud builds up behind the seal and keeps the piston from retracting all the way during normal use.   

[75cb550 (kyle)]

Before you do that (or is it too late?), you should remove the seal while you have everything apart and clean out the groove it lives in.  Crud builds up behind the seal and keeps the piston from retracting all the way during normal use.   

diddo...
you can use a 90 degree pic, but be careful. you dont want to score the groove either... good time to make sure piston and bore are smooth like a baby's butt.

[xfactor]

Before you do that (or is it too late?), you should remove the seal while you have everything apart and clean out the groove it lives in.  Crud builds up behind the seal and keeps the piston from retracting all the way during normal use.   

diddo...
you can use a 90 degree pic, but be careful. you dont want to score the groove either... good time to make sure piston and bore are smooth like a baby's butt.

I actually took apart the front brake solely for this reason. I got a front tire put on yesterday, and the guy that did it for me, pointed out that it was rubbing and was prob because the piston was sticking.


So the front is done, and I went to tackle the back, just going to bleed it and put some new fluid in it. Then I had trouble finding the bleeder valve. When looking at my book its pointing to a spot, where on my bike, is a screw.


I think the PO lost the bleeder valve, and replaced it with a screw.....

[75cb550 (kyle)]

nice.. gotta love that... at least they're cheap.

[BeSeeingYou]

Just a heads up on the rear.  It's a twin piston design so getting it apart is a bit more involved.  You do not have to split the two part caliper and if you did as the manual says I don't know how you would get the pistons out without some special tool.  I used a narrow long reach C clamp to hold one piston down and forced the other out by hooking it up to the front MC ( I was rebuilding the whole system so I had everything apart).  Clean that one up, add new seal, put it back together and do a quick bleed, put the clamp on the one you just cleaned and force out the other one.  There is just enough room but you may have to get a little ingenious too.  There is a small o ring between the two caliper halves and if you wanted to replace this once you have both piston back in place you can then change that one by splitting the caliper.  Do the inboard or upstream one first.