should i rebuild the brake calipers?

[mason79]

i have some ss lines ordered for the front of my f, and was wondering if anyone knows, if i clean out the m/c real well and bleed the system, will there be sludge left in the brake calipers?

is there a low spot/place where the sludge may settle in the calipers?

i'm trying to avoid rebuilding them as they don't leak or stick, and there is no rust.

i think the m/c could use a good cleaning though, and the old lines will be a thing of the past.

this will save a little money and a bunch of time, you can call me a lazy xs owner

[wingnut]

Slduge

Mason when I was working on my brakes I thought I had flushed the calipers out really well with brake clean and compressed air then with DOT 3. I put it all back together and one of them hung up so it had to be rebuilt. When I got it apart there was still sludge in the caliper even after the pints of brake fluid and cleaner I’d pumped thru it. If you want them clean inside take them apart. I reused the seals and boots on one and the worked great. Just clean them up with brake clean or DOT 3. Do not use petroleum based cleaners. It dose not react well with brake fluid. Makes more sludge.

[mason79]

okay, i gotta do the whole thing...

at least i'll stop, cause it ain't stoppin.

can you explain how the pistons come out? and is it easy? thanks wingnut!!

[Ken Talbot]

Yes, there will still be sludge in the calipers behind the pistons. Easiest way I've come across to get the pistons out is with a shot of compressed air from a rubber-tipped air nozzle. Put a heavily folded up rag between the piston and the other side of the caliper and keep your fingers well out of the way. Leave the bleeder in place, apply the tip of the nozzle to the hole the banjop bolt came out of, and give it a light shot on the trigger. Be ready to catch!

[mason79]

is there another way? cause i don't have a compressor

[pathfinder]

mason, I rebuilt mine in my apartment parking lot years ago. Vise grips on the piston above the groove that the dust boot fits in. Use the M/C to pump them out as much as possible. It takes awhile and does mar up the piston, but in an area that has no sealing surface. The square o-ring on the piston can most likely be saved by cleaning well with dot 3. I know I'm going to start something here, but I have been running dot 5 for years with no ill effects. I like dot 5 because you could wash the bike with it and not screw up the paint. Dot 3 make's a mess out of a good paint job.

[Ken Talbot]

Without a compressor, try the air hose at a gas station. Get a tubeless valve stem and press the rubber end against the banjo hole. Press the air chuck to the filler end of the valve stem and pop - out she goes!

[prometheus578]

Like Pathfinder stated, use the master cylinder to pump the piston out. Take the pads off first and keep the master topped off. (Keep the cover on the master cylinder when squeezing the lever, as brake fluid will squirt out the spooge hole and you'll paint the ceiling of your garage) Do one caliper at a time. Have a pan ready... makes a hell of a mess.
As for the compressed air method, Ken didn't stress this point enough, so I will. "KEEP YER BLOODY FINGERS OUT OF THE WAY", or that's just what you'll end up with.

[skids]

Brake fluid eats paint!!!

Originally posted by prometheus578
Like Pathfinder stated, use the master cylinder to pump the piston out. (SNIP)makes a hell of a mess.

[mason79]

will rebuid kits from mikes650.com fit?, i think the cross reference

xs650efgh

[mason79]

btw, for those constantly looking...

http://cgi.ebay.com/ebaymotors/ws/eB...%3AMEWA%3AIT:D

[84xj1100]

Not that I'm an expert by any means, but I have done my own calipers with the assistance of someone with an air compressor and by myself without.

Quite frankly the air compressor method actually scares me a little, in that the amount of force at which I saw the piston fly out of it's housing leads me to emphasize the warnings of other responders.

I would also shy away from the "vise grip" method as it can really marr up the piston and in doing so open the piston up to premature oxidization (rusting).

That would leave my endorsement with the messy push it out with brake fluid method. Although messy (with potential paint problems) at least you have control over the "velocity" at which the piston comes out and it doesn't marr up the piston itself. One other advantage is absence of "knuckle rapping" that may occur with the other two methods.

As my daughter would say "good luck with that".

Ed

[knewsom]

Someone (not sure if it was Prom or Randy) suggested to use a thick scrap of leather around the piston, and THEN grab it with the vicegrips, prventing any damage to it. I'm going to be using that method (heh, I've got a bunch of armor grade leather kicking around - I'm in the SCA) myself, since I don't have a compressor. I'll post again when I've done it with results.

[knewsom]

round and round she goes....

will it ever come out? nobody knows!

Actually, it did work, but was a major PITA. Just gotta be patient, keep on it, and eventually, she'll come free, and you'll be able to get at all the nasty gunk that's in there. Be prepared for a GOOD grip workout though - phew!

And definitely use THICK leather. I gave up at one point and stated just using the vicegrips alone on the piston, don't do that. it'll DEFINITELY score it up a bit, and doesn't work much better - not worth the risk, IMHO.

good luck.

-Kris

[mason79]

That would leave my endorsement with the messy push it out with brake fluid method. Although messy (with potential paint problems) at least you have control over the "velocity" at which the piston comes out and it doesn't marr up the piston itself. One other advantage is absence of "knuckle rapping" that may occur with the other two methods

i think i'll use a big bucket elevated by a milk crate to catch the dot3...

dirty work but someones gotta do it, i need to stop and will not want to go into the system for a while....