How do I install an adj. proportioning valve?

[v6turbojunkie]

I need to know everything about the install of an adjustable prop valve. I would assume that it needs to go on the front brake lines since I need to limit that pressure and shove more to the rear brakes. Do I put it between the master and stock valve or after the stock valve somewhere? Does the stock valve get reused? I noticed in summit's website are single inlet/outlet but had some choices about hole sizes (1/8, 7/16, 10X1.0) which one and do I need adapters? What brand?
If anyone can help please be thorough. Not to be a total pain but I want to make sure I do this right. Had a bad experience with shoddy brake job once and skidding down a country road at 60+ mph in a vehicle upside down sucks.

 

[DeltaT]

What brakes are you running? Do you have the stock master cylinder? Do you have the stock combo valve on there (that is the small block where all your brake lines go straight to, and it also controls your BRAKE trouble light)?

What problem are your trying to fix? Most adjustable proportioning valves are put in to lower the rear pressure. You want your front brakes to skid before the rear, or the car will tend to whip around.

Jim

 

[v6turbojunkie]

Originally posted by DeltaT
What brakes are you running? Do you have the stock master cylinder? Do you have the stock combo valve on there (that is the small block where all your brake lines go straight to, and it also controls your BRAKE trouble light)?

What problem are your trying to fix? Most adjustable proportioning valves are put in to lower the rear pressure. You want your front brakes to skid before the rear, or the car will tend to whip around.

Jim

I'm running a vacuum brake conversion with stock discs up front and 11X2" drums in rear. Yes, it still has the stock combo valve on the left frame rail just below the firewall. I can't hold boost at the line with the foot brake. I've tested the WHOLE system for problems with the local mechanics help and just don't believe there's enough hydraulic pressure at the rear. If I set the e-brake I can build lots of boost and @ 3400 rpm, with the foot brake just 2600 rpm and no boost before the front wheels start scooting. Oh yeah, I've switched to softer rear shoes and got to hold maybe a few more rpm's.

John

 

[DeltaT]

What stall speed converter do you have? A proper stall for your launch boost levels will help a lot. Are you running narrow front tires? Could a line lock kit be a help?

Jim

 

[v6turbojunkie]

Convertor is being restalled as we speak. This may solve the problems. I'm running street tires on the front, would my condition be worse if I were on a set of skinny front runners?
I have a line lock on the front wheels so I can do John Force burnouts without killing the rear shoes. Are you refering to an all wheel line lock? Never thought about that, do they work pretty good?

 

[KevinB]

I have about the same brake combo as you. To install the adj. PV, I took the rear brake line from the vacuum master cylinder (the front line) to the adj PV. From the APV, I went directly to the back brakes (bypassing the stock PV.) For the front brakes, I went from the master cylinder to the line lock to the front brakes. I am not using the stock PV at all. I can now get 10+ pounds of boost at the line with slicks. Also have a very good brake pedal
HTH,
Kevin

 

[v6turbojunkie]

Thanks for the info Kevin.