everetteladner

I have a 65 Mustang, 6 cyl. with drum brakes.
I am changing the mc bowl from single to dual bowl.
I am installing a booster.

Question: Do I need a proportional valve?
Question: If no, is there an potential problems with installing one. My buddy insists that a proportional valve is helpful on a car with drums

Thank you

jwog666

a proportioning valve is required on every car with rotors/drums. dont know about 4 wheel drum.

kalli

Question: Do I need a proportional valve?
i see them only on disc/drum cars. but it always can help if you can regulate the brake pressure for the back

Question: If no, is there an potential problems with installing one. My buddy insists that a proportional valve is helpful on a car with drums
no problems. as when you open tha valve fully it's the same as when it's not even in there

BTW: if you are installing a booster you might have problems with your car when you have manual transmission (clearance issues)

Kalli

rbrown22

What's your long term goal? No need for dual if you are planning on sticking with drum/drum..

Starfury

There is ALWAYS a need for a dual-reservoir m/c. It's a safety factor. There's a reason it became a requirement in '67.

That said, you're going to have a hard time cramming a twin-bowl m/c in a '65 car with a booster. I believe the only way to do it is to use a modern plastic bowl m/c to save space.

silverblue66

didnt they have original power brakes for drum on the early models. don't know about duel mc tho.
Kip

Starfury

Power brakes, yes, but they all had single-bowl m/c's. There's not a lot of room in there between the firewall and shock tower.

I forgot to mention, no, you don't need a proportioning valve for a 4-wheel drum system. It wouldn't hurt, but it's going to be nearly balanced front and rear. Usually with a 4-wheel drum system you make adjustments at the wheel to change brake balance.