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I am installing the 1584 dual master cylinder on my truck with drum brakes on the front and rear.

Do I need to install residual check valves on both the front and rear lines?


Do I need I one for the front and one rear or do I need four total?

Thank you,
Bob from South Dakota

This forum has many experts on brakes, master cylinders, etc. that can answer all your brake questions.
Your question seems to be asking if you need to put a "proportioning
valve" in line when you change from a singel to a dual chambered master cylinder. I've used proportioning
valves on race cars before. But that's an entirely different application then
what you're trying to do.
I'm sure you will get good advice from the others on the forum about your updating the master cylinder.

m37army wrote:I am installing the 1584 dual master cylinder on my truck with drum brakes on the front and rear.

Do I need to install residual check valves on both the front and rear lines?


Do I need I one for the front and one rear or do I need four total?

Thank you,
Bob from South Dakota

The original M/C has a residual check valve built in. The M/C you are changing to does not because it is designed for a disc system.. It will work great in the application, but you will need to include an in line 16 PSI residual check valve in both the front and rear circuit. Mount them as close as possible to the M/C.

Sir,
Thank You for your assistance.
Robert from South Dakota

Bob,
Don't forget the brake lite switch. You can "T" one in the front and one in the rear lines close to the master cylinder and wire them in series and add an indicator light to the dash utilizing the brake lite circuit. This will always come on when you hit the brakes unless one of the two systems looses pressure and you'll get an instant heads up that you lost half of your brakes.
Cheaper and more trouble free then a differential pressure switch.

Hi
I and have a 61 M37 that I'm putting in a 318 Poly. I have a couple questions as to the brake set up. I have the stock brakes and installed the 1584 dual MC. Do I need a proportioning valve? I believe they have residual check valves built into them. What is the purpose of the check valves?
Thanks for the help
Ken

Kenneth Cole wrote:Hi
I and have a 61 M37 that I'm putting in a 318 Poly. I have a couple questions as to the brake set up. I have the stock brakes and installed the 1584 dual MC. Do I need a proportioning valve? I believe they have residual check valves built into them. What is the purpose of the check valves?
Thanks for the help
Ken

There is no internal check valves in the 1584. You won't need a proportioning valve. You will need at least a 10# residual check valve in both circuits. The purpose is to keep all fluid from being pushed back into the reservoir when the brakes are released and the shoe return springs force the wheel cylinder pistons inward. If you don't have them, you will find it will be necessary to pump the pedal once to build pressure in the lines before each brake application. Install the check valves as close to the M/C as possible. You will also find you won't have really good brakes unless you install a remote mounted vacuum booster, it makes a huge difference, well worth the cost.

So Charles are they needed if running front/rear disks since it was designed for disk brakes origionally?

hndrsonj wrote:So Charles are they needed if running front/rear disks since it was designed for disk brakes origionally?

2# residual check valves are recommended for disc brakes, although they are not an absolute necessity.

Charles
Thanks for the info. Can I get the check valves at the auto stores and where would I get the vacuum booster?
Thanks again
Ken

Kenneth Cole wrote:Charles
Thanks for the info. Can I get the check valves at the auto stores and where would I get the vacuum booster?
Thanks again
Ken

Well there is a little more to a boosted system than just a booster, but yes the components can be purchased through any auto parts outlet, NAPA and others.