Testing a Proportioning Valve?
A 70 built after Jan 1 should have come with a combinaton valve.
If your car was built before then, then it has a proportioning valve after the distribution block with safety switch.
Pictures and chart in this booklet.
1970 Chrysler Imperial Hydraulic Brake Service Guide from the Master Technicians Service Conference Session 274
Test procedure is on page 10, and its also in the FSM.
But it requires having the pressure gages and adaptors.
I would
a) First bleed the brakes front and rear.
b) Then examine the rear shoes for signs of grabbing etc.
After that, then yes consider a rebuild kit for the prop valve or combo, whichever you have.
Also consider reducing the size of the rear wheel cylinders. Depending on the tires. pavement, weight distribution, front/rear heights, etc - sometimes slightly reducing the force on the shoes (by changing to slightly smaller wheel cylinders) is helpful.
A 70 built after Jan 1 should have come with a combinaton valve.
If your car was built before then, then it has a proportioning valve after the distribution block with safety switch.
Pictures and chart in this booklet.
1970 Chrysler Imperial Hydraulic Brake Service Guide from the Master Technicians Service Conference Session 274
Test procedure is on page 10, and its also in the FSM.
But it requires having the pressure gages and adaptors.
I would
a) First bleed the brakes front and rear.
b) Then examine the rear shoes for signs of grabbing etc.
After that, then yes consider a rebuild kit for the prop valve or combo, whichever you have.
Also consider reducing the size of the rear wheel cylinders. Depending on the tires. pavement, weight distribution, front/rear heights, etc - sometimes slightly reducing the force on the shoes (by changing to slightly smaller wheel cylinders) is helpful.