1979 Chevrolet Camaro

Brakes problem
1979 Chevy Camaro V8 Two Wheel Drive Automatic 100000 miles

I have purchased every thing new includeing
master cyl, proportioning valve, and all brake parts
for front disc and rear drums. This car has been sitting since 1997 and I am now restoreing it.
At first I had good brakes at the disc side but
nothing to the rear. After preping the master cyl.
via bench bleeding to remove all air bubbles, upon
installation of the master cyl when I lightly depress
the pedal air bubbles are again present in the
rear section of the master cyl. That feeds the drum brakes. The dash light is not on so I am sure the
proportioning valve is centered to allow fluid to
the front and back.I removed the line that goes
between the proportioning valve and the junction
mounted to the rear axle and it is clear.I am not sure what to do next.I used both a vacuum pump and
the standard method of fluid in a jar with the bleeder hose below the level of the brake fluid in the jar. Any Ideas? Thank you for your time
John Burkhalter
burkhaltej@sbcglobal. Net
April 21, 2009.

Try the other way where someone in the car pumps the brakes up and then holds the pedal down while you release the bleeder valve. You may have to do each side a couple of times. I have found a couple of cars that I had to bleed the brakes at least two times to get it to work right.

Apr 22, 2009.
I have tried that at least two times and still could not
get anything to the rear drums. Any other ideas?
I have been around cars a long time being a parts
man and building 2 other cars.1 for the street and
one for racing but I just can't figure this one out.
Thank you for your time and help
John Burkhalter
burkhaltej@sbcglobal. Net

Apr 22, 2009.
Ok, lets do this, you put portioning valve on and new master cylinder. When you use vacuum do you get brake fluid comming out the rear brakes bleeders? If you do then I would think that there may be a problem with the master cylinder. I have seen even new or rebuilt parts not working right.

Apr 22, 2009.
I have no fluid at the rear bleeders after trying
4 or 5 times.I spoke to a person that does brakes
and he said to make sure the piston in master Cyl
is allowing fluid to the rear brakes. If not then
maybe a spacer was needed between the booster
and the master cyl. The rod in the booster is not adjustable and it is not allowing the pedal to contact
the stoplight switch.I am going to measure lengths on a different booster to see if that is part of the problem.I will let you know the results

Apr 23, 2009.