My '71 Skylark was originally a 4 wheel drum car, I converted it to front discs with all factory parts. The proportioning valve was not changed, do I need a new one and if so, what part number/where do I get it? Thanks in advance for your replies.
https://www.summitracing.com/parts/clp-pvks-b1?seid=srese1 https://www.summitracing.com/parts/sum-760158?seid=srese1 You may fine them cheaper, but CPP parts have always been pretty good on both my conversions. Remove/eliminate the metering/distribution block from the frame, and run the two front lines on the front of the valve, and the rear line is a single that splits at the rear axle. (may be obvious, but wanted to mention) Make sure you pick up the bleed tool. Remove the pressure switch on top of the valve and screw the tool in to keep the proportioning valve from locking out the front or rear when you step on the pedal. (the valve will lock out the front or rear brakes when the pressure drops and the tool prevents that so you can pedal bleed the system)
@TrunkMonkey Oops, tagged wrong person earlier. Not to hijack the thread but I’m getting ready to bench bleed my master and then gravity bleed the lines. Would the distribution block on a 1970 version act the same as you mentioned above? Block out the front or rear if pressure is too low? And would I need the tool as well? Thanks Nick
No. The block is only similar to a splitter. But they, lines, junctions, calipers and wheel cylinders can get loaded with sludge and have restrictions. From old fluid, moisture absorbed, and corrosion. I have seen what looks like mud in lines of old and neglected systems. The perportioning type valve has a shuttle that is pushed forward or back and physically isolated the front or rear brake lines in event of loss if pressure so the remaining system does not lose its fluid and result in total brake failure.
Hi TrunkMonkey, I thought it was more of a hold off valve in terms of building pressure prior to sharing with the rear? Am I off base? Thanks, Mike
@TrunkMonkey thanks for the info. I have installed all new lines, rear cylinders, distribution block, hold off valve and master and rebuilt my calipers. @BuickV8Mike yes, I have a hold off valve up by the master cylinder. My understanding is that I need to press that button so that I can gravity bleed. If I push with the pedal to bleed, I don’t have to hold the button. I was concern about the block. Wasn’t sure if that need anything special. Or if it was a true pass thru for the fluid. I’m guessing for 71-72, they combined the distribution block and hold off valve into one piece creating the proportioning valve which needs that tool mentioned above.
Ya I grabbed spindles off 72 MC to upgrade to discs but I couldn't get to distribution block or as some people call it by other names. What i would like to do is buy either original 72 block or buy a repop that am certain can be used without a bunch of reducers etc.. I believe in 72 all functions are combined in one unit.I also believe everything marked as exact reproduction is a reasonable facsimile of a copy of original etc.
In 1971, disc brake cars used a combination valve. It incorporated the proportioning, hold off, and warning sections into one valve.
This valve- the one combining all functions is mounted directly on side of master? As opposed to down below on frame. No other valves needed?
Listed for Lemans-tagged for chevelle? I'm hoping I can locate proper mounting bracket and take it from there.You have to start somewhere.
You can buy the valve, MC to valve lines, bracket, safety switch/pigtail for less than $100. CCP (Classis Performance Products) Rather than throw the dice on a 50 year old part that your life depends upon. (But it costs me nothing to spend someone else's time and money )
My luck with repop parts hasn't been good, now I have this valve and it has the rear fitting with a stain on he flare seat. The upper fittings still have lines on them and the other flare is quite small so I can't really see. Once I discovered the # - bendix 0411 etc. More options opened up + am waiting for help from vendor who specializes in the old stuff.Some of the threads on this unit will require adapters to connect to standard line sizes.
The block I bought above prolly a dead end. What I have done recently is obtain rectangle master . This unit has rear reservoir roughly half size of front..Now the aftermarket proportion valve doesn't look so bad, Are the fittings on aforementioned part compatible with current drum block on car? Would someone run the rectangle master 72 using the 69 style block/ hold oof valve??
