400ex rear caliper?

[flyboy1294]

I am having an issue with my rear caliper on my 400ex. Whenever I pump the brakes or try to bleed them, fluid Pours out the emergency brake side of the caliper. I assume this means one of my gaskets has dried out and deteriorated.

From what I have read on here, this is a somewhat common problem with older, neglected bikes, but I am unsure what course of action I should take.

So, do I need to buy a rebuild kit for the caliper, buy a whole new caliper, or just buy the oring that has gone bad?

I appreciate it

[kbnorth99]

You can get a rebuild kit from your dealer for around $25. It will contain everything (minus a couple bolts) you need. What has probably happened is the the small o-ring that separates the main chamber of the caliper from the parking break side has gone out. Same thing happened to me last month. The rebuild is easy to do if you have a manual. Read all the way through the article before you start the job. The manual will call for a few NEW bolts to mount the caliper but my dealer says he has never replaced those bolts on any ex he has worked on. If I weren't in a hurry I would have ordered the bolts as well but I didn't realize that they weren't in the kit until it arrived and then it was too late to order before my camping trip. Inspect your brake pads too. If they are close to being worn out this is a good time to replace them. Same thing with the rotor. Read up on a couple threads about bleeding your brakes as well. It rarely works the way it is supposed to (for me anyway :( ) so be prepared just in case.

[killer454]

i think the rebuild kits are a joke to put in,when the caliper is probly woreout if it is an old atv.

i bought the rebuild kit 4 weeks ago for my 2000 400ex rear caliper and yes it still leaked after i was done with it.
so i was out of 25.00 for the rebuild kit,ended up buying a used caliper,master cylinder,lines,and resuivor for 60.00 used from here.
worked great
i would sugest buying a new caliper off ebay for 125.00 and save the 30.00 to put toward the new one.
or you could buy a good used one for less and hope like me.

if the atv is old i foundout the piston and cylinder in the caliper wear after a long time of use and the rebuild kit might not fix it.

this is my oppinion on this,i just went through it 4 weeks ago.

how can i put it,I WISH I DID NOT BUY THE REBUILD KIT FOR THE OLD WOREOUT 11 YEAR OLD CALIPER!

[kbnorth99]

You do have to be very careful when rebuilding the caliper. The seals around the piston can be easily ruined during the assembly process if you're not very very careful. I've never heard of a caliper wearing out, the piston yes but not a caliper. The caliper can be damaged by debris or if the piston deformed but other than that the the caliper itself is pretty much just a machined piece of aluminum. Mine has some pretty severe scaring and it's just fine. I did consider buying a new caliper instead of rebuilding but I wouldn't buy a used caliper. I would much rather rebuild and know it's done right than cross my fingers and hope I am getting a good unit instead of something that still needs to be rebuild anyway.

[Zakradu398]

Happenedto me a few weeks ago, I got A new o ring from napa for I think 7 cents and it was done with. Still working good

[flyboy1294]

Originally posted by Zakradu398
Happenedto me a few weeks ago, I got A new o ring from napa for I think 7 cents and it was done with. Still working good

This is what I'll try before I do anything else. Might as well inspect things before spending money.

[Zakradu398]

Not trying to thread jack but is there an o ring in the master cylinder because mine leAks a tiny bit