Beer should have bubbles, not brake fluid!

[Toolmaker Tim]

Just rebuilt the rear master cylinder, i filled it before installing it, and pumped the piston until brake fluid came out. Hooked up the brake line, hung a hose from the rear caliper and started bleeding the blasted thing. An hour later, several cuss words and enough air pumped through to supply the International Space Station for a week, there is no end in sight. Don't see anything wrong and I double checked assembly of the MC. Any idea's?

[newc4]

When I bleed I use aquarium clear tubing. This sometimes fractures allowing air in the bleed line.

You can try filling the bleed line with brake fluid before connecting it to the caliper bleed valve. It should displace any air in the caliper. As you pump the MC you can see whether fluid is advancing indicating that you're getting pressure in the system.

My front brakes don't bleed normally. I'll get fluid in the bleed line but no pressure if I close the valve. However, if I keep pumping is slowly builds. I'll let it sit and pump some more and it gets tight.

Good luck

[Incubus]

If you can't build up any pressure no matter how many times you pump it, you probably have an air leak somewhere. If you used new crush washers on the banjos that would be the first place I looked. Some of those washers require significant torque before they will smash and do their job.

Patrick

[Toolmaker Tim]

The fight continues

Gave up on the XS rear M/C and re installed the XJ master cylinder. Got it bled very quickly and easily. Things were looking up, then the spring that activates the brake switch broke. Guess I need to find a new on or a substitute. I guess it could be worse, but I just want to ride the dang bike!!!