Bracket Talk
Master cylinder question....

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November 22, 2022, 02:27 PM
62Galaxie
Master cylinder question....
Do SOME master cyl. have a built in means of applying more to the front wheels than the rears? I want to remove a line lock. These are manual brakes. Can one master cyl. exit line service the fronts and the other exit service the rears? I don't see any proportioning valve ANYWHERE.
November 22, 2022, 02:37 PM
rusty
one line to rear one to front.some are for drum om both ends some are for drum and disc.the disc will have built in residual valve.you will need to use a manual differential most likely to be safe


honesty is the best policy,insanity is a better deffense
1.036, 6.16@ 224

November 22, 2022, 02:41 PM
racerdude2054
I drove a car one time where a ball valve was in the drivers compartment to shut off fluid flow to the rear brakes
November 22, 2022, 03:27 PM
62Galaxie
quote:
Originally posted by rusty:
one line to rear one to front.some are for drum om both ends some are for drum and disc.the disc will have built in residual valve.you will need to use a manual differential most likely to be safe


What is "manual differential"? For 4 wheel disc brake, can't equal force be applied to front and rear...... no proportioning valve?
November 22, 2022, 04:24 PM
rusty
you should be able to get a master cylinder to do thatit will have built in residual valves


honesty is the best policy,insanity is a better deffense
1.036, 6.16@ 224

November 22, 2022, 04:25 PM
rusty
most drag cars reduce braking to front to avoid locking of front wheels


honesty is the best policy,insanity is a better deffense
1.036, 6.16@ 224

November 22, 2022, 08:05 PM
HS professor
quote:
Do SOME master cyl. have a built in means of applying more to the front wheels than the rears? I want to remove a line lock. These are manual brakes. Can one master cyl. exit line service the fronts and the other exit service the rears?


Not that I know of .........

Usually just use an adjustable proportioning valve if you need to adjust front to rear pressures.
November 22, 2022, 08:20 PM
Eman
Step bore master cys apply more pressure to one section than the other. S10's used step bores in some years. Most MC's are the same bore so the same size piston with the same pressure applied to the pedal applies equal pressure to each port. Some cars split the brakes diagonally lf/rr rf/lr.
Residual valves are used on drum brakes or if the MC is below the calipers. Factory cars haven't used residual valves on the drum end in many years, they control the fluid flow in the wheel cyls.
November 25, 2022, 03:18 PM
FootbrakeJim
quote:
Originally posted by HS professor:
Not that I know of .........
Usually just use an adjustable proportioning valve if you need to adjust front to rear pressures.

^^^ This. I use a Strange Engineering B3369 adjustable proportioning valve. It cost about $50 several years ago, and works very well. You turn a knob to make adjustments, so mount it where it is reasonably accessible. Just remember, the valve simply allows you to REDUCE the pressure through the line on which it is installed. On a drag car, you install it on the front brake system, to keep them from locking up, because you have a lot more tire on the rear. (It is the opposite on a street car, you would install it on the rear line to keep them from locking up before the fronts).


Dan "Jim" Moore
Much too young to feel this damn old!!