Why won't my brakes bleed

[ksurfer2]

Wilwood discs on all 4 corners of my 64 dodge. Manual master cylinder. Front brakes bleed fine. Out of the rear, I get nothing but air bubbles. I have tried bleeding with the brake pedal and with a vacuum pump with the same result. I have bench bled the master. I have removed the bleeder valves on each rear and they are clean and clear. I tried wrapping the treads with teflon tape in case the air was getting in though the threads. Were is all the air coming from? Level in the master is not going down (to replace the displaced air in the lines). There are no leaks in the brake lines (that would let air in). I am stumped.

 

[BeepBeepRR]

Is it possible you tripped the proportioning valve? You may have to reset that. When tripped it shuts off the rear brakes incase of a failure in either the rear wheel cylinders. THis way you still have front brakes. I use the word tripped but there is another way to explain it. I just don't have the words.

 

[ksurfer2]

Here is a photo of my master cylinder/line lock. The line coming out of the front of the master is what feeds the rear brakes, there is no proportioning valve like shown in the video.

 

[pnora]

When you bench bled the master are you sure you bled both halves. Lot of people make that mistake. I would re-bench bleed the master making sure you are compressing both halves. Then one all the air is out re-install the master, leave the caps off and gravity bleed one wheel at a time. Then do a pump and bleed one wheel at a time untill no air comes out. Are all your caliper bleeder screws on the top?

 

[pnora]

Here is a photo of my master cylinder/line lock. The line coming out of the front of the master is what feeds the rear brakes, there is no proportioning valve like shown in the video.View attachment 1117284 View attachment 1117285

That looks more like a line lock not a proportioning valve.

 

[ksurfer2]

yes, the caliper bleeder screws are facing up. The master cylinder has only one reservoir under the caps. There is do divider in the master separating the fronts and rears.

 

[ksurfer2]

That looks more like a line lock not a proportioning valve.

Yes, it is a line lock.

 

[pnora]

My bad I found the text on the photo.

 

[pnora]

yes, the caliper bleeder screws are facing up. The master cylinder has only one reservoir under the caps. There is do divider in the master separating the fronts and rears.

There should be a divider wall it is lower in the reservoir.

 

[ksurfer2]

Here are a couple more pics, the brakes, and the piece on the rear axle that sends fluid to each axle. On the top of this piece, there is a "cap" that is very loose, not threaded, but spins easily and feels like it could lift off easily.

 

[pnora]

Here are a couple more pics, the brakes, and the piece on the rear axle that sends fluid to each axle. On the top of this piece, there is a "cap" that is very loose, not threaded, but spins easily and feels like it could lift off easily.View attachment 1117296View attachment 1117297

Thats the axle vent. Do what I suggested and you will get brakes.

 

[pnora]

Are those 4 piston calipers? If so they have two topside bleeders. Both sides need to be bled on each caliper.

 

[ksurfer2]

Thats the axle vent. Do what I suggested and you will get brakes.

The brake lines run through the axel vent???? Back to the garage to retry the bench bleed of the master.

 

[ksurfer2]

There is only one bleeder valve on each brake.

 

[Garngie]

Remove the brake hose at the rear axle and check if fluid is coming through the lines from the front of the car. The rear hose commonly goes bad and can block your brake fluid

 

[ksurfer2]

There are 2 blenders, in need to take the wheel off to get to the other one. I will also check the lime from the front od the car. Dinner time, so back at this tomorrow.

 

[Mike67]

Is this a new install? Looks to be a Strange MC. It maybe that your stroke is not long enough to engage the rear bias.
I was reading that it (1.032 bore) is for 4 wheel disc with single piston up front and dual or 4 piston rears and a 5:1 pedal ratio. So the pushrod may need to be adjusted a little more ( lengthened)

 

[ksurfer2]

This was installed when I bought the car. Would the pushrod out of adjustment cause the bleeding issue??

 

[pnora]

There are 2 blenders, in need to take the wheel off to get to the other one. I will also check the lime from the front od the car. Dinner time, so back at this tomorrow.

Yes you need to pull the wheels to get to the outer ones. You should just do one wheel at a time alternating from inner to outer bleeder. Try that on all 4 wheels and see what happens.

 

[pnora]

This was installed when I bought the car. Would the pushrod out of adjustment cause the bleeding issue??

Could but forget about all the other whys and ifs. You need to bleed all the air out before looking or blaming other things.