Rear Brakes Won't Bleed

Big_John said:
Let's ask this question and work backwards.

Did everything work before you started replacing parts?
Click to expand...
The MC was stuck so no pedal movement started the this brake saga. With the MC removed the pedal and booster rod moved freely. I managed to pull the distribution block and gave it a good cleaning and all the ports flowed as they should. The rear rubber hose has already been replaced by PO.
I will try bleeding the system again this week hopefully with better results. On a positive note the trans is working :)
 
Scott 440 TNT said:
The MC was stuck so no pedal movement started the this brake saga. With the MC removed the pedal and booster rod moved freely. I managed to pull the distribution block and gave it a good cleaning and all the ports flowed as they should. The rear rubber hose has already been replaced by PO.
I will try bleeding the system again this week hopefully with better results. On a positive note the trans is working :)
Click to expand...

Wow... Never really heard of a master cylinder that was "stuck". That makes me wonder about a lot of things... Including if the pushrod was/is set correctly.

I would try cracking the fitting at the MC first, then try cracking the fitting before the rear brake hose. If you get fluid there, then crack the fitting on the rear of the wheel cylinder.

A lot of us, myself included, have had issues with offshore built wheel cylinders with bad bleeders or the like, so I can't discount that as a problem, but the best way is to find where the issue is.
 
Big_John said:
Wow... Never really heard of a master cylinder that was "stuck". That makes me wonder about a lot of things... Including if the pushrod was/is set correctly.

I would try cracking the fitting at the MC first, then try cracking the fitting before the rear brake hose. If you get fluid there, then crack the fitting on the rear of the wheel cylinder.

A lot of us, myself included, have had issues with offshore built wheel cylinders with bad bleeders or the like, so I can't discount that as a problem, but the best way is to find where the issue is.
Click to expand...
John, Did-do you ever use Never-Seez on your bleeder valves when you replace your brake cylinders and or calipers? I do and have been for 50 yearz. Time and $ well spent 'cuz when they're new its EZ and they never break off, lol Jer
 
BIGBARNEYCARS said:
John, Did-do you ever use Never-Seez on your bleeder valves when you replace your brake cylinders and or calipers? I do and have been for 50 yearz. Time and $ well spent 'cuz when they're new its EZ and they never break off, lol Jer
Click to expand...
I gotta say that I never have... and I should with my daily drivers at least. I've broken off bleeders because they've rusted in from the road salt they're exposed to. Of course, on the DD's, it's not unusual to replace the caliper anyway because it's seized, so a lot of times, the bleeder isn't a worry.
 
Big_John said:
I gotta say that I never have... and I should with my daily drivers at least. I've broken off bleeders because they've rusted in from the road salt they're exposed to. Of course, on the DD's, it's not unusual to replace the caliper anyway because it's seized, so a lot of times, the bleeder isn't a worry.
Click to expand...
A $6 dollar jug of that gray crap and you'll never snap off another one no matter long you live in the snow belt. Mother thought she had a better idea with some of her FWD aluminum block cars it the '80s + '90 too. You ever run into a 3.0L +3.3L, or a 3.6L that had aluminum thermostat housing with a high spot coming off the block that they had to install a bleeder valve in too. No corrosion there but the air pocket in that high spot would boil your antifreeze and the heat cycling under normal conditions would lock that air bleeder valve up too. Need a new thermostat? Buy a new aluminum MACHINED housing + the "stat". I called Michigan home from '61 to 2014 so I know about the white crap too. I keep a box of rubber gloves in my shop just to protect myself from that gray crap, lol. Stay well John, Jer
 
To nobody in particular, all future readers, that might want to start doing never-seize on brake parts -
Just to state teh obvious in case it's not obvious - be careful to put the never-seize only on the threads of a bleeder screw, not on the seat.
Never let any other chemicals mix with your brake fluid.
 
the ford and m-b vehicles i service come from the factory with rubber caps on the bleeders. they work. >300k in new england conditions and the bleeders don't seize.
 
rags said:
seen it. master contaminated with oil. swollen seals and locked solid.
Click to expand...
I have heard of that now that you say it.

A friend worked at a shop that had the contract to fix the cars that one of the oil change chains screwed up. Yea... actually had a contract and was quite busy fixing their screw ups. Think about that for a minute. He told me of a high end car that would lock the brakes completely and turned out they had topped off the brake fluid with trans fluid. It was an expensive repair.

But, to get back to the OP's issue, if that's the case, I would think it might have swelled the hose(s) too and could be the problem. But that's just thinking out loud without knowing much more about what happened.
 
BIGBARNEYCARS said:
A $6 dollar jug of that gray crap and you'll never snap off another one no matter long you live in the snow belt. Mother thought she had a better idea with some of her FWD aluminum block cars it the '80s + '90 too. You ever run into a 3.0L +3.3L, or a 3.6L that had aluminum thermostat housing with a high spot coming off the block that they had to install a bleeder valve in too. No corrosion there but the air pocket in that high spot would boil your antifreeze and the heat cycling under normal conditions would lock that air bleeder valve up too. Need a new thermostat? Buy a new aluminum MACHINED housing + the "stat". I called Michigan home from '61 to 2014 so I know about the white crap too. I keep a box of rubber gloves in my shop just to protect myself from that gray crap, lol.
Click to expand...

It gets everywhere no matter how hard you try for it not to. Nose always itches as soon as the bottle is opened. I think I bought a can in 1973 that I still use.

I do use it on the threads for the pins.

BIGBARNEYCARS said:
Stay well John, Jer
Click to expand...

Thanks Jer. You too.
 
Big_John said:
I would think it might have swelled the hose(s) too and could be the problem.
Click to expand...
crack the line at the top of the hose and hit the brake. he'd know in short order. if the seal on the m/c cover is swollen, it's a dead give away. had one recently in an f350 4wd. ruined the abs controller.
 
Big_John said:
I have heard of that now that you say it.

A friend worked at a shop that had the contract to fix the cars that one of the oil change chains screwed up. Yea... actually had a contract and was quite busy fixing their screw ups. Think about that for a minute. He told me of a high end car that would lock the brakes completely and turned out they had topped off the brake fluid with trans fluid. It was an expensive repair.

But, to get back to the OP's issue, if that's the case, I would think it might have swelled the hose(s) too and could be the problem. But that's just thinking out loud without knowing much more about what happened.
Click to expand...

If the MC piston was frozen in the bore, that could also mean that moisture got in the unit somehow, usually from the cap being left off. If the system got wet, the brake lines are suspect and could have a pinhole someplace that is sucking air and preventing a proper bleed.

Dave
 
I had Davea's problem. No matter what I did rear brakes wouldn't bleed. Then I bought a pressure bleeder. Pumped it up to 20psi. Was opening/closing the bleeder screws and saw a big puddle under the prop valve. Cranked really hard on the rear line connections at the valve. No luck, with brake fluid dripping on me I looked up and saw fluid leaking out of the rear brake connection on the master cylinder. Used the floor jack handle on the line wrench torqued it so tight I thought I was going to break it off. That stopped the leak and I can bleed them now. No more pedal going nearly to the floor. A leak is bidirectional, fluid goes out, air comes in...
 
If original master cylinders and wheel cylinder bores are not pitted or damaged a cylinder hone will clean them up. Seals are available.
I choose this path over new repop units. I've sent three sets of new rear wheel cylinders back due to cheap manufacturing issues and had a front replacement that would not bleed due to a defect.
Reseal the originals if possible. You end up with a OEM quality part for less money than a new replacement. And it's easy.
 
Assume you got a replacement for your Rear Brake Hose. Hope that fixed your problem. My car has exactly the same problem. Is this the correct part replacement you used...............NEW DORMAN REAR BRAKE HYDRAULIC HOSE CHRYSLER DESOTO DODGE PLYMOUTH H24717 ?
 
So I’ve finally made myself go back to working on the brakes.
You were right, the rubber brake hoses are all clogged up. Getting new hoses front and back and that’s making things flow better.

image.jpg
 
I reckon some folks ARTERIES are in a very similar condition! I should check the one hose to my rear brakes. They bled this past summer when I upgraded to the dual pot Bendix master cylinder but ... Brakes are one of those components which I prefer to inspect BEFORE they break! Good admonitory pic.
 
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