Ok, so I'm adding a rear disc kit in. Right now I have a 2 bolt 1 1/32" master cylinder - I can't remember from what app - think it was an 80something 5th avenue? KH discs in front, disc brake proportioning/distribution block, and 10 x 1 3/4" drums (stock a body 8 3/4") in rear.

The adjustable proportioning valve - can I put that between the master and the stock one, or does it have to go after the stock one? Or should I switch the stock valve back to a drum one then add the adjustable valve?

I would rather put it under the hood for convenience but if I have to do under car plumbing I will.

I'm pretty sure you cut the single line running to the rear brakes from the factory valve and install the adjutable valve. Make sure the valve is mounted solidly and not supported by the brakeline.

-James

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What James said works well. You can also put it in the line between the MC (front pot, for rear brakes) and distribution block instead.

Lou

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Home of Slant6-powered fun machines since 1988

Strapping it to the master cylinder would be easiest as long as it doesn't cause any other complications. Are there any performance issues, putting it before or after the stock valve?

I wonder if it can reduce pressure enough to activate the brake light switch? I may as well unplug it, I'm not sure how useful that thing is - only time I ever seen it come on was when the master completely failed. Not when the pedal was initially touched but only after it sunk to the floor. By that time I think you would know your brakes are failing you don't need a red dash light for that.

I still have an unused prop valve I bought years ago. I put Lincoln discs on my DeSoto and Explorer discs on my Valaint. In both cases the prop valve was unnecessary because the cars stopped evenly without them.

The Valaint uses a stock 75 Valiant manual M/C for discs. The car stops about the same as with the former 10"drums.

The DeSoto uses a Corvette manual M/C for 4 wheel discs (about 1965 I think)

Im not sure I would even bother with the prop V/V unless you get rear wheel lockup.

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Yeah....Im the one who destroyed this rare, vintage automobile.....

No diff between before or after stock "valve," which is really just a junction block with a low press switch in it.

Note that I believe this aftermarket valve does not really reduce pressure, just the inital brake bite. You would need a lever or hydraulic lever system inside there to actually reduce pressure.

Lou

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Home of Slant6-powered fun machines since 1988

Lou - I thought the drum/drum unit was just a distro block but the disc/drum unit was a distro block with narrowed passages to do the proportioning. Either way for this issue I guess it doesn't matter.

if its adjustable it would be nice to have it right there under the hood. u could change it as the weather and traction change, eh

I thought all old Mope blocks were just open passages. Could be wrong.

Best way to proportion is with disc caliper piston sizes and drum wheel cyl sizes.

I think the best place to put that valve is right behind your left foot while driving, and have the knob poking through the floor! Maybe have a safety cover on it... Haven't done that yet myself.

Lou

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Home of Slant6-powered fun machines since 1988