Brake bleeding !

[Mopar mike]

It doesent make sens, i wanted to bleed the brake system today so i pusht the pedal and my friend opend the bleeding screw but no oil or air at all came out, this was the right rear wheel, whats happens now, what to do ? The front brakes is ok but it seems to be a rear axel problem. Maybe sleeping on it will help, or maybe sombody knows what to do.

 

[polara71]

cant be an axle problem. You had your foot on the pedal and he opened the bleed screw? You sure he opened it?

 

[Mopar mike]

Yes. The pedal and mastercyl is ok, the front brakes id ok, and i opend both lines from master cyl under pressure and oil comes out, but no pressure to the rear.

 

[polara71]

Collapsed line or proportioning valve?

 

[Mopar mike]

All lines checkt, but that "valve" is that the "block" the lines go to from master cyl ?

 

[commando1]

You have to trace the line going backwards.
Disconnect the line the rear brake from the Y-block on the rear axle. Then pump and see what happens. Then go from there.

 

[Newp]

You have to trace the line going backwards.
Disconnect the line the rear brake from the Y-block on the rear axle. Then pump and see what happens. Then go from there.

What he said x2.

May be the rubber line from the body to rear axle is collapsed.

 

[1978 NYB]

I would start by taking the master cylinder cover off and checking the brake fluid first. I would try to bleed the brakes before taking anything else apart. Just my opinion........

Just in case you need a little help bleeding the brakes.

Always bleed the brakes one wheel at a time. Start from the farthest wheel cylinder away from the master cylinder. Bleed them in this sequence, right rear, left rear, right front, left front. It takes 2 people to do it. One person to pump and hold the brakes and the other to open and close the bleeder valve on the wheel cylinder (caliper if you have front disc brakes). Tell the guy pumping the brakes to pump them up until he gets a stiff pedal and then tell him to hold the brake pedal down with pressure of his foot. It may take a couple of times bleeding the wheel cylinder until the pedal starts to get stiff. This is normal. Open the bleeder valve and either air or bubbles will come out. The brake pedal will go to the floor when you open the bleeder valve. Have him keep pressure on the brake pedal as you close (tighten) the bleeder valve. Once the bleeder valve is closed, tell him to pump up the brake pedal again and hold pressure on the pedal while you open the bleeder valve again. Keep doing this until you have a solid stream of break fluid coming out of the bleeder valve. Check the master cylinder about every 3rd time you open the bleeder valve. You don't want the master to become empty and pump air into the lines. Move to each wheel in the sequence that I stated earlier. I would check to see if you have any wetness around the drum. If you do a wheel cylinder could be leaking.

 

[Mopar mike]

I have changed the inside of the master cyl, all new and all in rear brakes is new. When we pump and hold down the pedal and opens the bleeding valve nothing happens, no oil or air is coming out, and the pedal is not sinking. I have opend the lines from master cyl, one at a time while pushing the pedal, then oil comes out and pedal is sinking. This is the rear brakes only, the front works right.

 

[BillGrissom]

I had that once w/ an 82 Aries caliper. I asked the helper to push the pedal with both feet as hard as possible and a bunch of rust gunk blew out. Try removing the bleeder screw to make a bigger hole. If still nothing, as mentioned, start upstream looking for a blockage. Sounds like you have a new rear hose. Did you blow out the lines after putting in new parts? Since the Aries incident, I have used DOT 5 (silicone) in all my non-ABS cars, and no more rust. You can read many humorous statements from those who have never used it, even from big companies like "don't mix w/ glycol or bad things happen" (tested and untrue). The U.S. Military uses only DOT 5.

 

[cm23uoc]

So you should work as Stan said from the back, the fault must be somewhere after the master cylinder from your description.
By the way I happened to bleed the brakes of the dd yesterday with a bleeding kit a just bought after decades of pumping which is not that good for the internal rubber parts especially with an already well used master cylinder.
This is a rather cheap kit for about 35 Dollars but as I had several sources who use this Eezibleed kit successfully for a longer period of time I finally ordered it as well and it works. You use the pressure of the spare tire inflated to a max. of 20 psi for bleeding. Haven't tried it on the Chrysler, you would have to take a spare cover and drill a hole into to have a proper cap to put on pressure.

 

[1970cat]

front disc or drum? if front disc, the prop valve could be stuck

 

[bluefury361]

I've found that the best way to isolate a problem is to start at the source and work back to the problem.

As far as bleading..... I don't agree with the pump and apply pressure before opening the bleeder method.
I bench bleed the master cylinder..... then verify it is full of fluid. Go to the rear of the car and open both bleeders.... Then go watch some cartoons, or something and allow the fluid to find it's way to the cylinders. When there is fluid evident at both bleeders, close them and open both front bleeders.... same deal. (verify the master cylinder is full).
Once theres fluid visible at all bleeders you should have a fairly firm pedal and it's only a matter of a couple light strokes on the pedal..... open each bleeder one at a time, (right rear, left rear, right front, left front).... and SLOWLY push the pedal to the floor and hold it for a few seconds..... then close the bleeder and repeat. You can do it by yourself.

 

[Mopar mike]

front disc or drum? if front disc, the prop valve could be stuck

I have drum brakes, this "prop valve" were is that located and how does it look like ?

 

[Mopar mike]

Ther is no oil reaching the rear brakes, front brakes is working normal, this "port valve" someone wrote abouth, can it cause a problem like this ?

I've found that the best way to isolate a problem is to start at the source and work back to the problem.

As far as bleading..... I don't agree with the pump and apply pressure before opening the bleeder method.
I bench bleed the master cylinder..... then verify it is full of fluid. Go to the rear of the car and open both bleeders.... Then go watch some cartoons, or something and allow the fluid to find it's way to the cylinders. When there is fluid evident at both bleeders, close them and open both front bleeders.... same deal. (verify the master cylinder is full).
Once theres fluid visible at all bleeders you should have a fairly firm pedal and it's only a matter of a couple light strokes on the pedal..... open each bleeder one at a time, (right rear, left rear, right front, left front).... and SLOWLY push the pedal to the floor and hold it for a few seconds..... then close the bleeder and repeat. You can do it by yourself.

 

[commando1]

I have drum brakes, this "prop valve" were is that located and how does it look like ?

Follow the lines from the M/C. The first whatchamacallit it connects to is the proportioning valve.

 

[Mopar mike]

Can this valve stopp the brake fluid from reaching the rear brakes ? And the front brakes is ok ?

Follow the lines from the M/C. The first whatchamacallit it connects to is the proportioning valve.

 

[commando1]

Stolen from: http://inlinetube.com/Prop Valves/pro_valves.htm

Since disc brakes were new in 1967, the valve was still being worked out for the next few years. The 1967-70 valves could consist of as many as three elements and the valves would not work properly without all the pieces. Both 1967-70 factory drum and factory disc cars have (or had) a distribution block which is identical whether the car was drum or disc. Although very similar in appearance to a proportioning valve, the distribution block does not alter brake line pressure. The distribution block keeps front and rear systems separate, splits the left and right front lines and houses the sending unit for the brake failure warning light. The 1967-1970 factory disc vehicles employed an additional valve, referred to as a hold-off valve, mounted at the master cylinder. The final component in the 1967-70 factory disc brake systems was a correction valve typically located in the front to rear brake line for the rear brakes. This valve was not used in every factory disc brake car, but would make the front to rear line two pieces with the valve usually found mounted near the floor pan of the car. An original 1967-70 disc car can be factory correct without the correction valve, but not without the hold-off valve at the master cylinder.

 

[Mopar mike]

OMG, This valve must be the problem. And loosen it sems to be a problem to, no space for Tools there. Cutting the lines, and then new lines must be the way to go. I dont like it but i must have brakes in rear too. Now i diselike that valve..:angry4: :icon_axe:

Stolen from: http://inlinetube.com/Prop Valves/pro_valves.htm

 

[bluefury361]

OMG, This valve must be the problem. And loosen it sems to be a problem to, no space for Tools there. Cutting the lines, and then new lines must be the way to go.

Unless your brake lines are rusty or damaged they should come loose. Maybe dismount the porportioning valve from the frame will give you room to work. There should be an electric wire there connected to a stud that can be removed with a socket. Sometimes removing that will allow the internal piston to recenter and solve your problem.