Any good reason to use an adjustable proportioning valve on my 70 Mach with front disc and rear drums? Should I stay with the stock distribution block until down the road when I will upgrade to rear disc. How does the adjustable work anyway? It has one entering port and one exiting port. Would I need two valves to run the front and rear? Anyone have pics of their setup? Where is the best place to mount the adjustable valves in the engine bay?
Adjustable Proportioning Valve?
- Thread starter wickedmach1
- Start date
TurboDoctor
Founding Member
I would stay with the stock set up until you get ready to swap for four wheel disks. Some people add an adjustable vavle for personal preferance but you dont really need to.
mdjay
Premium Sponsor
) oh the possibilities, except i'm sure thats not the smartest thing to do 
mfp4073
Founding Member
Ok, consider this...once upon a time your distibution valve was disigned for a specific car. The car you have now has different tires and weight distribution. The proportioning valve willl allow you to tune your car such that under full braking that both front and rear will lock up the same time. This is a point that is individual to each car based on many things.
pabear89
Active Member
wickedmach1 said:
Add the valve when you change the rear to disc, in line to the rear only.
inner fender below the master is a good spot.
The valve will allow you to adjust the brake pressure to the rear disc's so they will have enough power to stop without locking.
that will keep your tail end from trying to pass you in a hard stop.
PB
LanceMach
Founding Member
If you have a problem with the rear wheels locking up during braking you should consider adding it. I wouldn't adjust the rears to correct any problem - they should always be adjusted properly, not loosened up to compensate for an imbalance (just my opinion).
The valve would go in the line that runs to the rear brakes (after the dist block). One side should be marked "In" and that's where the line from the dist block goes.
Chances are you won't need one 99.9% of the time. Even for people who drive like maniacs, the brakes are rarely pushed hard enough to make one necessary. However, in an emergency braking situation (or on road courses), you want the brakes working as efficiently as possible and that means having them balanced so they share the load.
You could check them by finding a nice stretch of road and clamping down on the brakes as hard as you can (making sure nobody is behind you first!). If the rears lock up first, you may want to consider adding the valve. If you do add one, be sure to test the balance every couple months to make sure it's still in balance.
The valve would go in the line that runs to the rear brakes (after the dist block). One side should be marked "In" and that's where the line from the dist block goes.
Chances are you won't need one 99.9% of the time. Even for people who drive like maniacs, the brakes are rarely pushed hard enough to make one necessary. However, in an emergency braking situation (or on road courses), you want the brakes working as efficiently as possible and that means having them balanced so they share the load.
You could check them by finding a nice stretch of road and clamping down on the brakes as hard as you can (making sure nobody is behind you first!). If the rears lock up first, you may want to consider adding the valve. If you do add one, be sure to test the balance every couple months to make sure it's still in balance.
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