Brake Caliper Rebuild.

[njload]

last rebuild on all calipers was in the 80's. Got all the parts and was wondering can the calipers be dipped in carb dip to clean?

[spyug]

No!

Clean the outside with cleaner of your choice i.e. Simply Green, Spray 9 whatever. Clean the insides only with fresh brake fluid (including the rubber seal).

If you find rust or gunk in the bore clean it out with fine steel wool and be sure to blow out any particles. If the piston shows any pitting or cracking on the skirt (part that sits in the bore) you should replace it as rust can grow there when the bike is in storage say over a winter and overtime can cause the piston to seize.

Take your time and do a good job as your life could depend on them.

Good luck.

[njload]

spyug thanks for the reply. I haven't taken them off the bike yet but ordered all new pistons and seals. Thanks for the info on cleaning and I have lots of 000 steel wool lying around and a good air compressor.

[njload]

Why is it not good to carb dip the calipers? Just wondering?

[TooManyToys]

It really should not be an issue as long as all the chemical is washed clean of the housing when you are done. A first wash by dipping into hot soapy water followed by cool water rinse and immediate drying is not a bad method. Corrosion in the bore is a freedom of movement issue and should be addressed, but the most critical surface is the groove for the square o-ring that provides the caliper body seal. This needs to be cleared of any corrosion/debris while not changing it's dimensions. The next critical sealing surface is the piston OD, and if pitted needs to be replaced.

When you are assembling the caliper it's best to use brake assembly fluid rather then brake fluid. Brake fluid is hydroscopic so any residual fluid left between the o-ring seal and the caliper boot increases the chance of corrosion. Plus the assembly fluid is slipperier then brake fluid which makes reassembly easier.

[Nessism]

Dipping the caliper body in carb dip cleaner is fine as long as you realize the paint on the outside of the body will get damaged. Be very careful to fully rinse the caliper afterward with soap and water. Simple Green to clean the caliper, inside and out, is much easier.

As mentioned by Jack, clean the groove area carefully. Scotchbrite works well to remove any corrosion. Needless to say, make sure all the parts are clean and dry before reassembly.

Brake assembly lube would be fine, but I've never seen that stuff sold anywhere. I use regular brake fluid. For the sliding pins, moly caliper grease, the high temp stuff, works well.

Also needless to say... replace your brake lines while the calipers are apart. Building your own lines from Earl's parts is easy, Z1 Enterprises and various other places sell Goodrich lines, or there is a place in Canada called Reinsport (or similar) which makes lines for reasonable prices. Check this thread for more info...http://www.thegsresources.com/_forum...d.php?t=114521

[TooManyToys]

Amazon, Summit, NAPA ...... it's there.

I don't have in my tag line but I managed Vehicle Testing in the US for one of the worlds largest brake material manufacturers (you know the company as Ferodo). For our aftermarket side of testing, especially during poor economic times, I had my group rebuild calipers and wheel cylinders (had to be done for every test, usually 500 miles) instead of buying new. Some calipers were put up on the shelf for a short time and you could really see the difference in corrosion if someone got lazy and did not use AF but rather brake fluid. We also had two cases of an O-Ring failure where they were nicked during assembly before I mandated AF. This is not saying that many do not have an issue just using brake fluid, but as I mentioned why do you want to leave something that will absorb water under the caliper dust boot. The dust boot is not a great seal and is only compromised more so when the caliper body has developed corrosion pitting in the groove surface.

Admittedly I'm getting really picky but after working in the industry for 30 years I see brakes as the biggest safety device on a vehicle. And I'm just a little OCD.

[Seaking]

Good thing I found this thread! I'm in the process of pulling the brakes off an 83 GS650G and this will help a lot. Stopping is more important than speed.. I'm trying to be as meticulous as possible with these.. The only rust damage are the caliper axle bolts.. one is smooth, the others kinda rough feeling.. best I replace those.. Boots are fine, replacing the piston seal. And will try to located brake assembly lube if possible..

[1_v8_merc]

Make sure you rebuild the Master Cylinder too.
If any debri clogs that relief valve, you're going over the handle bars.
Think of it as a tiny switch that makes your brakes go from 0-to-100% instantly.