hey old

been watching your post bout the old 1 ton ford, no biggey to get a master cly to work on it for off road use. just go to the junk yard get a good one that is bout the same size, build a adapter plat to bolt to the ford fire wall, build a rod from brake pedal to master cly with bout a 1/8" free play, put a tee on the master cly so you have 1 line to tie into the ford line bled em and go. I have a 46 chevy army truck with a 1975 datsun master cly tie into 1 datsun disk brake on the tranfer case, stops on a dime and gives you change back. also have a 76 chevy 4x4 with a 4 cly isuz diesel the turbocharger is in the way for the vacumm can on the master cly on that one, had to use a hydraulic assist unit off a 86 one ton chevy, then trun it upside down to clear the turbcharger, benn stopin her for 5 years that way.

I have been thinking about put on a newer double type cylinder and since I have a number of junk cars/truck using the proportioning valve off one of them. I do not plan to put it on the road again but would be nice but since it would need a new windshield and all new wires and a lot of other thing not worth it just need a farm small dump truck that will stop. I hate messing up my gates which I have done with this truck plus the wife hit a tree with it and messed up the radiator at one time. I asked her why she didn't shut it off and she said I didn't think of that

I didn't use a proportioning valve just put a tee in there. worked fine for off road. but wife never drove it either. lol.

I don't think the proportioning valve is needed on an all drum system. Only seen them used with disk/drum setups.

I'd look for a dual chamber master from an early drum/drum pickup or heavy car with a bore within 1/16" of your old one.

Back when I was working the vehicals had the proportioning valve on, They were Dodge Caravan's, and they messed up the action of the brakes in the fact that I only had 2 wheel or front brakes and no rear wheel brakes. Operated of the tilt of the van due to load and garage adjusted them way beyond the mounting holes to give me any rear wheel brakes and the job involved a stop on average every half mile for 250-300 stops a day it is something noteciable when your rear brakes are not working. Don't think my earlier Ramblers with the double cylinder had them and the cars I was driving when I quit working, Olds Ceira's, don't ever remembering them having them on. They are just to give you 90% front brakes when you actually need equal or more power on the rear brakes.My concerne would be to get the same capacity to both ends as the dual cylinders are not the same on both ends in size. On your truck I would tie both ends of the cylinder together to a common brake line so neither end would put out the wrong amount of fluid and just use the single line system. If you would be going on the road it would not be legal but on your own property who can say anything and it would be better than no brakes.

Old,
When I built my A, I have 50's chevy drums up front, and 9 inch Ford drums on back. Used a 1968-70ish chevy Nova, 4 wheel drum master cylinder. No OEM style proportioning valve. I do have an adjustable valve in the rear depending if I have the 10in slicks on (pictured) or street tires (29x15x15 M/Ts). This setup has been working since 1999 wit no problems.

I did fab a bracket to mount the m/c on the frame below floor board. And built a custom length rod from the m/c to the pedal.

As I mentioned in my other post, you might want do a little cross-referencing on the bore size of the one you pick. I believe your truck originally had an 1 1/4 m/c bore. You'd hate to fab up a new m/c and find out you don't have enough fluid volume.

Rick