Bleeding Brakes.. Problem?

[Archie340]

Finished replacing the rear drum brakes on my 71 charger. No issues till I decided to bleed them since the car has been sitting for many years. Had my wife almost stand on the brake pedal and fluid was just weeping out of the bleeder on the drivers side and nothing out of the passenger side. The car has power front disk and is hibernating for the winter so I didn't bother starting it. Seems like I should get more fluid pressure even without the help of the brake booster. Does this seem normal?

 

[mopar12372]

get a clear 1/2 liter water bottle pour some brake fluid little shake pour out
fill 1/4 way up get some vaccuum line that fits and seals on bleeder screw
loosen bleeder screw attach rubber vaccuum line to bleeder put line into brake fluid in bottle
have someone pump brakes sloooow watch bottle for bubbles stop when bubbles stop tighten bleeder screw
do this on all wheels .\
make sure master cylinder has fluid at all times
done

 

[red72]

Could be that the bleeder ports on the wheel cylinders are partially restricted or stopped up. I have had this happen, just remove them from the cylinder and clean the bleeder hole.

 

[mopar 3 B]

When you get done put some rubber caps on the bleeders will keep them clean.

 

[Archie340]

Thanks, cleaned the bleeders, took them out and still not getting any brake pressure to speak of. Purchased a Mityvac and couldn't get much flow either. I will probably wait till I start the motor, stand on the brake and see if I can clear it otherwise I have a feeling it's going to cost me some $$$ to get them working again.

 

[mopar 3 B]

The cups in the master cylinder have probably gone bad and pressure is not being created.

 

[miller]

If your not getting much fluid to the rear brakes, could be same prob I have...clogged brake lines. Supposely, alcohol is the best to flush brake tubing.

You might try breaking the rear brake line loose at the distribution block. Open both brake bleeders on the rear wheels, and blow compressed air through the lines. Even if you have to break loose every 'joint' going back to the rear wheels. Mine was clogged at the tubing 'Y' on the rear axle.

Anyway, need to make sure your getting free flow, from the distributor block, to both rear brakes, and go from there.

 

[rscurtis]

I'll second that. You shouldn't need booster pressure to bleed brakes. Simple brake systems like these should actually gravity bleed if you're not in a hurry.

 

[clazar]

Maybe the hold off valve is stuck. I had a similar problem with my RR. The pedal was hard as a rock. I opened the bleeders at all the wheels to release pressure. I let it sit for a few hours & it was fine to bleed.

Chuck

 

[mopar 3 B]

Your master cylinder and braking system in operating condition should max. about 300 psi of line pressure. Why would you want to break the lines loose to blow 120 psi dirty air threw them?

 

[HT413]

If your not getting much fluid to the rear brakes, could be same prob I have...clogged brake lines. Supposely, alcohol is the best to flush brake tubing.

You might try breaking the rear brake line loose at the distribution block. Open both brake bleeders on the rear wheels, and blow compressed air through the lines. Even if you have to break loose every 'joint' going back to the rear wheels. Mine was clogged at the tubing 'Y' on the rear axle.

Anyway, need to make sure your getting free flow, from the distributor block, to both rear brakes, and go from there.

I think putting anything besides brake fluid in the lines is a bad idea. Compressed air can bring or cause condensation. Water is bad. Alcohol will break down / contaminate the fluid and who really knows when it's all flushed out.

Flush brake fluid only with similar brake fluid.

 

[miller]

I think putting anything besides brake fluid in the lines is a bad idea. Compressed air can bring or cause condensation. Water is bad. Alcohol will break down / contaminate the fluid and who really knows when it's all flushed out.

Flush brake fluid only with similar brake fluid.

Agreed! Unless the brake fluid is contaminated. That's where the blocked lines would come into play, and the intention would be to flush the lines to get the contaminated fluid out. He said the car had sat for a long time. Any source of air or water will contaminate brake fluid, which happened on mine.

Everything I've read on the matter says to use alcohol (recommended) to clean out those lines. Yeah...that means opening up the rear brakes system, flushing the lines, and starting fresh. Simply using new brake fluid might not 'clean' the lines, if their clogged with crap. Using compressed air to blow out the open lines doesn't hurt nothing.

 

[Speedbird]

I think you are going to find a problem with your master cylinder. Especially if you start it with the booster in play with the same results.
That thing will put enough pressure on the lines to blow any obstruction out. (Sooner or later).
Here is something unrelated that gave me fits.
Well maybe not totally since you have a flex line on your rear body to diff connection.
The front flex lines on an older system were plugging up with trash.
The inner dimension is very small and when you stepped on the peddle the line would expand and the trash would get in.
When you let off the peddle the pressure would go down and the line would contract plugging the lines.
It made the front brakes drag for a few minutes till the pressure normalized in the calipers.
What was the "fix"? Just open it up and bleed the trash on out.

 

[RustyRatRod]

Very simple to diagnose instead of all the "I thinks". Get your wife to press the brake pedal and hold it firmly. While she is doing that, starting at the right rear, crack the line loose going to the wheel cylinder, then the left. The proceed to the next junction which will be the block on the rear axle and crack those loose. Continue up the rear line until you find fluid pressure. If the master cylinder was bad, the pedal would be low, because the rear side has a LOT to do with pedal height. It sounds like you have an obstruction somewhere. Breaking the lines loose like I described will find it. Whether it is a piece of trash or perhaps a valve not working correctly, you will find it in that manner. I actually found a small ROCK in a rear brake line once.

 

[HT413]

Very simple to diagnose instead of all the "I thinks". Get your wife to press the brake pedal and hold it firmly. While she is doing that, starting at the right rear, crack the line loose going to the wheel cylinder, then the left. The proceed to the next junction which will be the block on the rear axle and crack those loose. Continue up the rear line until you find fluid pressure. If the master cylinder was bad, the pedal would be low, because the rear side has a LOT to do with pedal height. It sounds like you have an obstruction somewhere. Breaking the lines loose like I described will find it. Whether it is a piece of trash or perhaps a valve not working correctly, you will find it in that manner. I actually found a small ROCK in a rear brake line once.

So who's this rustyratrod guy anyhow? Doesn't ring a bell.

 

[MoparMitch]

Please dissemble the rear flex brake hose and check it. Many times they will deteriorate from the inside and block flow.The rubber gets old and brittle.

 

[miller]

Or the hose can kink from age, pretty much closing it off.

Heh. 'New' fluid I got out of mine looked like real dirty water. Fairly dark. That was from air contamination, coming in at a bad connection in the brake line. (I had re-done/re-placed the entire system.)

What does your fluid look like, Archie340? Don't forget the brake cylinders at the drum brakes can 'leak', too, and pull air into the system.

 

[Speedbird]

Please dissemble the rear flex brake hose and check it. Many times they will deteriorate from the inside and block flow.The rubber gets old and brittle.

Yea, what he said.

 

[OldFolksMopar]

I am in the process of all new components on my cars rear end. Ha! The intermediate hose from the rear line to the Tee on the axle was plugged up. I would check the front brakes and see if you have good flow. If not, then you have a good starting point.

 

[Speedbird]

I am in the process of all new components on my cars rear end. Ha! The intermediate hose from the rear line to the Tee on the axle was plugged up. I would check the front brakes and see if you have good flow. If not, then you have a good starting point.

Yea, that's what drove me nuts when I saved an old A body one time. The rubber will expand enough to let trash in and collapse on the stuff when you let off. WTH was making my brakes drag? But I was able to blow it out with bleeding.