So I replaced the rear brake lined from the master cylinder all the was back to the drums yesterday and I can't get the drums to bleed. I opened the bleeder valves all the way up even while I had someone in the jeep holding down the pedal. So while trying to figure out the problem I opened up the T-fitting on the axle and still no fluid. Any ideas?

 

Have access to a vacuum bleeder.

 

open bleeders and remove master cyl cap let it gravity bleed. after fluid appears close bleeder and bleed as normal

 

So I tried opening the bleeders completely and letting them sit for an hour or two with the cap off-nothing. Took the line off at the junction on the axle-nothing. Took the line of at the master cylinder and pumped the brakes even-still nothing. No idea where to go from here. I'm assuming there is a blockage in the MC somewhere

 

look for any pinched lines. close your bleeders pump the hell outa the pedal till that SOB is tight then open your bleeders slow. may haveto doitone or three times but should work.

 

No pinched lines. I just replaced everything from the MC all the way to the drums. When I close em up and pump should I do that with the cap off the MC or on?

 

Having the same problem after replacing my master cylinder. Have not replaced any brake lines. Is it possible that either of us could have tripped the proportioning valve preventing flow to the rear drums?

 

You don't want to pump the brakes with the master cylinder cover off as the fluid will go the path of least resistance.... simply out the top....

 

Figured out my issue. Proportioning valve had closed off the rear line. Removed the nut off front of the valve. Took out spring and sliding valve. Replaced the cap and pumped brakes. Fluid out of both bleeders. Replaced the sliding valve, spring and cap. Pumped brakes and there was still fluid out of the bleeders. Not sure how you're actually supposed to reset the valve, but it seemed as soon as there was fluid going through there it opened up no problem. Try it out, see if it works for you.

 

When bleeding brakes, it is best to bleed the back brakes first and then the front. For the guy replacing the rear brake lines, losening one of the front bleeder screws and hooking a hose up to direct the fluid to a jar would let the back circuit build pressure. Bleed the back brakes and then bleed the front circuit.

 

I'm guessing you had a leak in the rear lines somewhere? That is what is supposed to happen, that valve senses the imbalance and blocks off the leaking line to try to save the reservoir from emptying out. It will sit most of it's life without moving much, so when it does it often sticks. Sometimes you can re-center it by doing the hilbilly stomp on the brake pedal a couple of times, or just resetting it by hand is fine.

 

this worked for me, thanks