This has been a nightmare for awhile now...last year I had it in 2 different shops where the master cylinder, booster and prop. valve were all replaced. It left the last shop stopping much better, but I still wasn't convinced it was like new. I just went out to bleed the brakes and on the RR a mixture of air and fluid comes out (with a power bleeder), mostly air and the air never stops. I can suck 3 quarts of fresh fluid all the way through and still get a bunch or air coming through. On the LR absolutely nothing comes out. When I crack the valve, it just drips down the back side of the drum and nothing even comes out of the hose. The only thing I haven't replaced is the wheel cylinders...but from reading these online forums it sounds like that might not help.
Thanks in advance for your help guys.

 

Vehilce info would be nice, but I don't think it really matters...

Have you tried disconnecting stuff up from the LR wheel? Disconnect it from the splitter on the axle. Fluid should come out. Then your wheel cylinder is bad. Those are easy to relace anyways. I'm assuming your front brakes bleed fine? Have you tried not using the power bleeder?

 

89 V6 4WD truck.
Front brakes bleed fine, same result bleeding by pumping pedal.
I'm going to go try disconnecting it at the splitter and see what happens, thanks!

 

Let me know what you find out!

 

For your LR wheel, it sounds like your bleeder screw is plugged up. Happened to me. Remove the bleeder completely, and blow compressed air in it from the end that you connect the hose to (so any dirt flies back out through the threaded end.) Should work OK after that.

Not sure about the RR wheel. Do you have any evidence of a leak anywhere?

 

Just replace the rear wheel cyls. They're cheap and it's good peace of mind anyway. While you're at it, blow your rear brake lines out with compressed air or replace them too.

 

Problem solved! I ended up having to bleed them the old fashioned way with the pedal but everything is figured out now. Thanks for the help guys, glad I found the site!