Brake Calipers

new here and too bikes!

I just got my first bike, xj700 85. Its in ok shape but everything looks like it has never been changed. Started going through the bike and started with the brakes. I got new lines because mine were shot. today i opened up the calipers and there was gunk in everythinggggggggg. i posted a pic below.

I bought a bunch of things to rebuild the calipers before i opened them and saw the shape of the inside. Are these beyond repair because of all the gunk throughout the system and rust in the pistons?

thanks much!

 

Not necessarily. The inside of the piston doesn't matter; it's the outside where the seals ride.

The best thing to dissolve old dried brake fluid is brake fluid. The stuff that won't come out can be "kissed" with the flame from a propane torch, turning it into dust that easily flakes off.

 

Thanks for the reply

What about all the gunk build up inside where the brake fluid flows? When I bled them there was actually particles of stuff that came out

 

I strongly suggest you get some braided lines

http://www.xjbikes.com/Forums/viewtopic/t=44636.html

 

Thanks Adrian, already got some from chacal

 

Do you have a compressor?

 

Get some cheap DOT4 and flush it through the system until it comes out clean. Or, if you've already got the caliper in bits, take the piston out and flush it through with brake cleaner.

 

did you even bother to read the op?

CN

 

No I didn't actually, I just took a random guess... :roll:

What was your contribution again?

 

Yes I have a compressor. The caliper is in peices already. Can I put some water im the holes and blow them out until they're completely dry?

 

You have to clean all that out. It's usually a good idea to replace the hollow banjo bolts as well, because they're often difficult to get clean inside. A lot of those particles could also be bits of the insides of the old lines.

You'll need to disassemble, clean and rebuild the master cylinder as well as the calipers; thoroughly clean (or replace as I recommended) the banjo bolts, install new crush washers, etc.

The whole system needs to be thoroughly cleaned out.

 

If you check the link in my signature, you'll see what I just did with my calipers on page 3.

FYI, if you don't want to kiss anything with flames, I found that when I sprayed the gunk down with brake cleaner fluid and let it dry, it became dry and crumbly, and scraped out easily with a metal pick.

Old metalsmithing trick: if you don't have a metal pick, make one with a donor coat-hanger and a metal file.

 

Personally I flushed it all with brake cleaner and gave everything a damned good squirt of air, everything looked good after that, make sure you're wearing eye protection though