[Scott MH]

i am having a slight problem with my brakes on my 69 impala...they are power drum brakes all the way around. i just replaced all of the springs and wheel cylinders. before i did this it was pulling hard to the driver side. i found that an auto adjustment screw was not engaging. i fixed that problem, bled the brakes, did the reverse and hard braking thing a few times and went for a test drive. now my car pulls to the pass. side then the driver side, then back to the pass. side. could this be the proportioning valve?

[Badbird]

Be advised, there is no proportioning valve on drum brake cars, that's only for disc/drum brake cars and besides it only controls the balance between the front and rear brakes, not side to side....It seems as though the brakes aren't adjusted properly!.....After going for a test drive just feel how hot the wheels or drums are then you can determine which brakes are adjusted too tight.

[Scott MH]

should i loosen them all the way then let them self adjust?
drum/drums have distribution blocks correct?

[JimM]

The distribution block only passes the fluid thru, it doesn't control it.

If she darts in either direction, you're probably pretty close on the adjustment.
The auto adjustment doesn't work worth a damn. You gotta do it by hand. Just adjust em so there is just a slite drag when you spin the wheel. Do all 4, and repeat every thousand miles.