Must have been late when I posted last night..but I mistakenly posted I had an F3 when I actually have a F4, 1952 dulas in the rear. I have a 1951 F3, it has a 1.25 inch master cylinder with hydrovac booster. I would like to upgrade to a bolt on dual reservoir master cylinder and booster for safety's sake. It also seems to be missing the parking brake. (original applied friction to the tranny/drive line area just rear of the tranny) Probably a victim of the upgraded transmisson. Any ideas on where/what to purchase? I see many aftermarket upgrades for the 1/2 ton master cylinder which has 1 1/8 inch master cylinder but none for the bigger bore. Any ideas? I can rehab the stock untis, but if something blows I'll be brakeless barreling down the highway!

 

Howdy,

I considered the same thing for my 55 F-600.

The problem is that it uses a single res master cyl and the "Hydro booster" all together.


A dual system might work well on the front brakes but since my back brakes have 2 large wheel cyls per wheel I suspect that the rear reservoir on a dual system might have enough volume to operate the rears correctly when the front brakes are getting enough pressure to work. You might end up only applying the front brakes with "travel" to go before the back brakes start to apply. I don't know if there's an easy answer.

To get a dual res to work I think you'd have to know what the fluid volume requirements are for for the front vs the back and select a master cyl that would supply that volume (approx).

My F-600 has dual piston cylinders (2 per rear wheel) and single piston cyls (1 per wheel) in the front. (I thought only trailers had single piston wheel cyls)


No one has a split system upgrade for the bigger (old) trucks. I wonder how the newer big trucks are set up. Does anyone know year they went to split systems?

It's also possible that they went to 1 cyl per wheel on the rear later also.
I haven't looked at the brakes on newer big trucks....maybe someone else here can pipe in?



I rebuilt my brakes to include a rebuilt Hyro-booster. They work perfect. (Of course if I have 1 of the 6 wheel cyls leak.....I'll be relying on the emrg brake!)




Regards,


Rick

 

I may be way out of line here, but it's late I'm bored. So here's my two cents. Consider using a large single res and a Wilwood proportioning valve to balance front to back. If you really want two reservoirs, hook it up backwards, with the back res to the front brakes and the front res to rear brakes. Then use the proportioning valve to limit the rear brakes to an appropriate level. That would allow you to adjust the bias of the rear end to compensate for the load you're carrying, like adjusting trailer brakes.

I love my F-100 with the beautifully simple cross block with one line in, two out to the front and one out to the rear. Too bad my F-600 isn't as simple.

 

Well, you're NOT!.....(outta line that is!)

You know I have considered using a manual (non boosted 2 res master cyl) and 2 Hydro Boosters. one for the front and one for the back.

I don't know how well it would work but I suspect a proportionaing valve would then be required. This would allow separate systems for front and back. It would be a little more expensive but at least there would be plenty of volume available.