brake help!!!

[towrecker]

well i am in the process of a brake retrofit on a 63 c-30 useing parts off a 69 gmc to do it but one thing has me stomped there is a block conected to the master on the 69 its a drum drum truck it has the brake warning switch in it ...what in the heck is it ? do i need to use it ? i really think it is just for the warning switch am i right ??? help please
thanks ,
jason

[rico7769]

Its the proportioning valve. It functions to distribute pressure to the front and rear cylinders at the correct ratio. The switch is wired into it for your warning light in the dash. Other than the fluid becoming too low in the master, the switch can be excited through a frozen proportioning valve. It can be removed but may need to be reset once you reinstall it. It plays a vital role in your braking system.

[towrecker]

on drum brakes i need it ?? if so the valve i have is off a half ton and the truck its going on is a 1 ton and you said reseting it ?? help me out here this is greek to me lol

[Longhorn Man]

nope, it is not a proportioning valve, it is a distruibution valve.
Not the same thing.
It does do more than just control the warning light though, if you have a brake line blow out, it will block off the end of the system that has the problem. This helps give you some braking ability when this happens.
Now the head scratcher is... why use a 69 as a donor... it still has 4 wheel drums like your 63.

[towrecker]

all i was out to do was split my brakes front and rear and get a double booster my 63 is a wrecker had power brakes little single booster and single master just looking to make it stop a little better and the 69 booster fit my booster bracket with nomore than a little work with my dremel

[Longhorn Man]

good enough reason.
I sometimes forget that a split system drum/drum system, is MUCH safer than what came before it.

[towrecker]

not to mention it will stop 10 times better with this set up so the brake block is a good idea on my 63 right but not a have to right ?

[Longhorn Man]

pretty much