Quote:
Originally Posted by Steve Shauger
If i recall the function of the valve on the frame was to keep a specified amout of pressure so the drum shoes did not fully retract when no pedal pressure was applied. This valve prevented a delayed engagement of the rear drum shoes, when brakes were applied.
|
Steve,
The November 69 Chevrolet Service News quoted in John Z's CRG report was specifically about the 70 Nova with Disc Brakes. CSN called it a Pressure Regulating Valve. It prevented the rear brakes from locking up.
Eddie,
The Pressure Regulating Valve (3982304) was used on all 70 Novas with Disc/Drum brakes. The valve was on the subframe from the first part of 70 production. Later production is was under the master cylinder.
While researching this I noticed that the Camaro valve (3908326) looks just like 3982304. Parts books states that it was for:
67 with AC, (not sure why)
67-69 396 Except 4 Wheel Disc Brake,
68-69 350 Except 4 Wheel Disc Brake,
68-69 327 w/4-Speed Except 4 Wheel Disc Brake,
This would indicate that the cars came standard with Disc/Drum should get it. This was safety feature after all. Not only did the Nova get it in 70, but so did the Chevelle w/Disc Brakes. There were two Chevelle designs.
JL8 Z's wouldn't need it. 12 bolts axles generally went on cars with front disc bakes. Maybe the 302 in the Z did not necessitate such lockup protection. Other than that, it is a mystery why there is no completely logical pattern based on CRG data collection.
Greg.