[Fordblue]

I just installed a new booster and master cylinder from WCCC on my 67. New pads on the front, new wheel cylinders on the rear and new hoses front and rear.

The front bled with no problem and are working great.

No matter what I try, I can't get fluid to the rear wheel cylinders.
I've done the two man pedal pumping method and the vacuum pump on the rear bleeders and even pulled the hard line apart where it goes to the hose to the rear axle and hooked the vacuum pump up there and still get nothing.

It holds vacuum and won't pull any fluid through.

Does this sound like the proportioning valve at the back of the car has siezed up?
It hasn't been driven in a couple of years and the c4 is on my workbench right now getting rebuilt, so I'm trying to get it to go and stop reliably all in one shot.

Thanks,
Robert

 

[DrCougar]

Sounds more like the valve in the distribution block is frozen. The original intent of the valve was to isolate either the front or rear brakes if one set failed. It would shut down that set. If the valve gets frozen there is no amount of pressure or vacuum that will move it. You need to take it out, remove the plunger, clean it and put new seals in it. Then you will be able to bleed the whole system.

 

[flatblack67]

there could be rust in the rear lines jamming them up if theyre from 67 still

 

[Don Rush]

By chance does the inside of your proportioning valve look like this? probably time for a rebuild!

<center></center> The picture above shows the flexible grease gun hose attached to one end of the valve with a sheet-rock screw threaded into the hole in the brass piston. Prior to setting this up we got the end opposite of the grease gun really hot, not glowing but HOT! Look at the picture below, this came from a car that had been parked outside for 20 years. It was REALLY stuck but we can honestly say it came apart in minutes with minimal effort.
<center></center>

 

[Cedar Rapids Ia]

Holy crap!! That needs a "Stent".... STAT!!!

 

[Art]

Sounds more like the valve in the distribution block is frozen. The original intent of the valve was to isolate either the front or rear brakes if one set failed. It would shut down that set. If the valve gets frozen there is no amount of pressure or vacuum that will move it. You need to take it out, remove the plunger, clean it and put new seals in it. Then you will be able to bleed the whole system.

+1
Is the BRAKE light on?
Break the line loose at the "in" side of the proportioning valve and have someone depress the pedal.

Also could be a constricted hose.

 

[Art]

Do you have a service that rebuilds these?
I've always just thrown them on the shelf and used an aftermarket adjustable.

By chance does the inside of your proportioning valve look like this? probably time for a rebuild!

<center></center> The picture above shows the flexible grease gun hose attached to one end of the valve with a sheet-rock screw threaded into the hole in the brass piston. Prior to setting this up we got the end opposite of the grease gun really hot, not glowing but HOT! Look at the picture below, this came from a car that had been parked outside for 20 years. It was REALLY stuck but we can honestly say it came apart in minutes with minimal effort.
<center></center>