I just rebuilt the brakes on my pickup. New master cylinder, calipers, shoes, pads and rubber lines. I can bleed the front two calipers but I am getting nothing out of the rear brakes. Please don’t tell me I have to replace the hard lines as well. Any one know of a trick or hack? Tomorrow I am going to climb back under that pile of *&%$# and try to trace the line to see if I can spot something… Anyone want to buy a pickup?
When the system is near empty the proportioning valve can lock in one position isolating the other. After bleeding the master cylinder pump the brake pedal to build pressure in the system. This may center the proportioning valve and allow flow to the rear so you can complete the bleed process.
Thanks. I’ll try that.
If the vehicle has ABS, you need to read this.
If the truck is raised so that the rear axle is down the proportioning valve may be fully closed.
I’ve used those kind of locking clamps doctors use in surgery to clamp of blood vessels to debug this kind of problem. Hemostats I think they are called. Tool shops carry those too, for car use. Use them clamp off the circuits (at places there are rubber hoses) to isolate the path that seems to be causing the problem. Then just step through it connector by connector until you find a place where there’s fluid going in, but none coming out.
That’s good info about the proportioning valve-I’ll have to store that away.
I had to replace the hard lines on my '93 Ranger some 6 years ago; they had started to rust internally and would no longer function. If you rule out the valve, I would try cracking loose the lines at the ‘T’, see if you get flow there, if not, work your way toward the front of the truck until you find good fluid flow.
When you replaced the shoes, did you look over the springs etc. inside the drums? For $15 or so, you can get a kit with new parts to redo both back brakes.
I replaced every thing I could replace except for the hard lines. I have a good hand pump and I get a very small amount of air and fluid out of the right rear. But I have been trying for days and that is all I get. I did not bench bleed the new master cylinder but I read that you don’t have to. I might just take the master cylinder off and start over with a bench bleed. Thanks for every ones input. I will look into some of the suggestions you have posted.
The bleeding process goes much faster when you bench bleed the master cylinder first.
Get an assistant to pump the brake pedal for you as you bleed the brakes the traditional way, that hand pump doesn’t seem to be getting the job done.
I suspect the proportioning valve is the problem but the vehicle is level. I just don’t know how to open the proportioning valve. I have tried what the book says to do but I still get nothing. Thanks.
Yea I guess I have to tie my friend to the steering wheel until the job is done. He doesn’t sit still for too long. Maybe that should be another post, “How to tie your friend to the steering wheel long enough…”
lol … I once broke up w/a gf mine b/c she wouldn’t be patient enough to stay in the car long enough to help me bleed my VW Rabbit’s brakes … lol …
You can get a bench bleeding kit, with several different size fittings and some short 1/8" hoses for like $10. I’d take the lines off, install the correct fittings and hoses, and do it while on the truck. That makes it a one man job. It took probably a hundred strokes on the last master I replaced to get fluid throughout it. Then, hook your brake lines back up, and two man bleed the rest of the system. One precaution-don’t ‘floor’ the pedal while pumping; you will run the internal seals past the holes and scar/cut them, then you will need to replace the master again.
Thank you to everyone who replied to this post. I didn’t hear about it or read about it any where, nor did I ever have to do this before but the thing that fixed it was the car had to be running. Once I tried that the brakes just bled out as they should. Oh well. “That’s what you get in Cracker Jacks!”