For the last few days my pedal has been traveling a bit too much before the brakes engage. I was thinking air in the system so I set out to bleed them last night. It was way overdue for a flush anyway. I started with the RR bleeder screw and ran into my first problem - I could only get a little fluid to come out. I tried pressing the pedal and using my MitiVac. The reservoir was full.
With that I moved over to the LR to see what would happen. Well the screw was frozen so I have some PB Blaster working on it. I'll have to try again tonight. The only thing more I could do was try and bleed the front lines. They work fine after a little persuasion with the screws.
Without knowing if the LR will bleed or not, I'm taking a SWAG and saying the M/C is bad. If I get the screw loose and the LR cylinder responds then the problem is probably in the RR area. I won't install the M/C until I know both rear brake lines are dead.

 

How new are the front pads/rear shoes? You will get more brake travel when the pads are old and lacking material.

Are you getting the red break light yet?

Bleeding might help, but if the pads need replaced, you will still have travel.

Good luck with that LR bleeder screw and keep on spraying that sucker. If it breaks, get ready to start cussing.

 

The pads and shoes are fairly new as well as the rotors and drums. The only explanation I can come up with at this point regarding not being able to push fluid out of the RR bleeder is that the M/C plunger for the rear circuit is bad. I'll know more tomorrow.

 

may have leak by in the combination/proportioning valve.
corrosion is a common problem in them.

 

Air in the system usually results in spongy pedal feel. If the pedal goes to the floor every time, there is a leak. But if it settles to a lower level, it could be the rear brake shoes not settling correctly. You can try adjusting them with the star nut or the old back up and slam on the brakes to try to adjust them into position. The star nut has a ratchet that allows the nut to turn just one way, and that's the way you want to turn it.

 

When I bled my system last year I could get NO fluid out the bleed screws, they were plugged, put some new ones on or poke the ball plungers with a paper clip while spraying with WD40 or similar. Also my pedal travel was long but my fluid was being lost to a leak in the Combi/prop valve. I repaired the combi valve & bled the system & she is like new again!
If M/C is bad on one side I think you would get the RABS light come on.
Aeroman.

 

That reminds me, I tried to bleed a brake on a car once where very little was trickling out of the hole after I removed the screw. My sister was helping me by stepping on the pedal, but it wasn't doing much. So we started the engine and had her step on the pedal again. This time, with power assist on the pedal, something popped through, and shot fluid everywhere. But it started as little squirts to the sides, and then a straight up gusher. It must have been a clod of rust build up.

But this sudden rush of fluid out the front brake pushed the shuttle valve in the combination valve to one side, and tripped the brake warning light. It also effectively shut off the front brake circuit, so there was only rear brakes, which was not as effective as the fronts, and the pedal stroke was long. I fixed it by opening a rear bleed screw and pumping the pedal just enough to push the shuttle valve back into place. I had the assistance of a continuity beeper connected between the shuttle valve switch and ground to let me know when the valve has been properly re-seated (it stops beeping).

People have done this before, but I don't think it's a good idea to get WD40 into brake lines. The petroleum based solvents can destroy the seals designed for brake fluid. If you need to flush brake parts, use brake fluid.

 

Yes........ no WD40 in the hydraulic oil!! ( although you are going to bleed the oil so any contamination should come out, but still not a good idea).
Take the bleed screws off before doing any flushing or cleaning & clean in brake fluid before re-installation.

Aeroman.

 

Maybe one of your brake pads was assembled wrong.
Van would steer to one side when braking.
If the pedal feels spongy then one of you Master cyl. seals has gone bad.
If this is true you are topping off brake fluid every once in a while.
If not, then you have a rear brake adjustment issue. Something broke on the rear brake adjusting mechanism and your brake piston is stuck retracted (this creates no pressure when bleeding)
Good luck!!