1963 B500
Like so:
Buy Cardone Hydro-Vac Power Brake Booster - Remanufactured 51-8030 at Advance Auto Parts
This is the same principle as the on-the-firewall set ups like a car or pickup, but a bit more powerful.
There is a primary master that feeds pressure to this unit, which in turn feeds more pressure to the wheel cylinders.
Is that the way your vehicle is set up?
There is some discussion here, indicating that some late '70s and '80s mediums had dual circuit hydro-vac set ups.
There are also later hydro-boost set ups with electrical backup.
Hydroboosted drum type brakes [Archive] - Cummins 4BT & Diesel Conversions Forums
If you are just trying to do away with the hydro-vac and just have a vacuum boosted master on the firewall, that might be difficult to do give the fluid requirements. Do you have dual cylinders in the rear wheels?
Sorry if this isn't what you are looking for. I think you need to stick with medium truck parts and not try to adapt pickup or car parts.
http://www.autoatlanta.com/centric/s...p?pn=130.65068
Last edited by uglybus; Sep 8, 2013 at 04:39 PM. Reason: left out link
Wow--I'm sure those brakes worked, but it seems like a pretty "weak" system compared to what they put on F500/600 trucks in the day, with the frame mounted hydro-vac.
In looking for a formula for the master, I found:
Reference / FAQ's: Master Cylinders
Power brake with dual mc conversion kits....cars and F100 and Chev 3100s...
Booster / Master Conversion Kits
They might have something that will work. You need a drum brake MC, and if I'm reading the whole brake thing correctly, the fluid capacity with a drum set up is less than disc. Of course, with the way these old vehicles poop out wheel cylinders, maybe a 10 gallon fluid reserve would be a good idea.....

Another outfit, if they will talk to you about your set up:
Results for HYDROVACS:medium duty truck
Brake talk, maybe a late '70s C60 for a firewall mounted dual circuit MC. You'd have to adapt it for mounting--childs play, right?








