brake upgrade questions ,Chrysler master cylinder..

[awbrown]

I am posting a pic ,it appears my truck has a Chrysler master cylinder , no proportioning valve and of course it is still drum brakes all 4 corners.. My question is this , I know Chrysler master cylinder like this were used on drum brakes , but were they used without proportioning valves??
My son had a brake line start leaking , and of course he never noticed , so I go to move the truck and the pedal goes to the floor , it still had brakes ,but the front of the master cylinder was empty .rear line was leaking .... I am no Chrysler expert so I am hoping someone here is...

[Sharps40]

Never seen one with a Chrysler Master on it. But having done a conversion on my 64 & 65 from manual single pot master to manual dual pot (drum/drum) No proportioning valve is needed with the 67 and up C10 dual masters. Same is true for the C10 Drum/Drum power master....the proportioning is in master cylinder.

As I recall, you should not need a proportioning valve until you have a disc/drum set up.

There are some smarter folks on here, they'll pop in directly.

[awbrown]

That is what I was thinking , but wanted to be sure....Thanks

[Sharps40]

Well, all that said, if the back plum locks up and drags before the front and yer ass swings around in the other lane, then ya prolly need a proportioning valve for the rear line.

[Captainfab]

No proportioning valve is needed for a drum/drum braking system. Just for the disc/drum and disc/disc systems.

[Sharps40]

See, I tol ya somebody smarter than me was gonna pop in here. Thanks Capt!

[awbrown]

It always worked normal so I thought it was OK , that being said I do need to replace the line from the master cylinder because it has 2 compression fittings in it and I also need a new rear brake hose because it is the wrong one and it has no mount . and the crimps have rusted away ,they look too thin for my liking..so it is kind of floating around ... Hopefully my son learned about adjusting brakes and maintainance .. I hope...