More Brake Conversion Questions

[B. Kirkpatrick]

I've been following some other posts about converting my brake system to vacuum assist and they never really specify what kind of proportioning valve to use..found one from an '87 mustang but it has drum brakes on the rear, does THIS matter?? can I use this valve or should it be from a vehicle with 4 wheel disk brakes? :confused:

[Nick]

No, you can't, which is why it hasn't been listed as a possible valve. ;) Proportioning valves are calibrated based on vehicle weight and the type of brakes used in addition to the desired handling during braking. It is very important to use the right proportioning valve to achieve maximum braking efficiency while maintaining stability during braking. Check the other recent thread on ABS brakes. The last resort if you can't find a proportioning valve is to use and adjustable one, but you will need to do a lot of brake testing from a variety of speeds to manually set the brake bias.

Have you run the diagnostic test on the brake system in the Tech section? Usually, it's much, much easier to fix the system and probably less expensive than to convert.

[pro-five-oh]

Disc brakes need more volume of fluid to operate properly, so I doubt that prop valve would be good.

[SilverFox]

The best way is to plumb the fronts straight from the MC and place a manaul/aftermarket porp valve on the rear line. This way you get uninterupted front brake service and the ability to dial in the rear settings according to safety/your preference.