The Stovebolt Site Forums The Parking Lot Big Bolts 52 2-ton Hydrovac/dual system/beating a dead horse?

I know this has come up a lot, but after searching a bit, I still have an unanswered question.

If I had the room, like by moving the master cyl, why not run a conventional style vacuum boosted dual res master cylinder.
Provided you could link it to the brake pedal, is there a reason why not? Doesn't it work basically the same way as the hydrovac?

The master of coarse would need to be one that would work with drum/drum brakes and the correct bore size. (haven't got that far yet)

This is on my 52 2t dump truck, it's brakes need a complete overhaul anyway.

Hy Bryan Barratt, there is no problem doing what you suggest, you seem to have a good handle on the cautions involved, hope that helps.

I installed a hydroboost on my 41 one ton and since I've gotten the bugs worked out: It works greaaaaaaaaaaaaaaaaat!
And it looks allot better than the vacume diaphragm.

I've started thinking about hydroboost. Power steering might be nice too.

The problem will be in finding a dual reservoir master cylinder with a bore big enough to displace sufficient fluid to apply those BIG drum brake wheel cylinders. I believe the rear axle has brakes with two wheel cylinders per drum, doesn't it? The Hydrovac has a large, long stroke cylinder that moves a LOT of fluid, and the fluid from the master cylinder at the pedal just acts as a pilot signal to trigger the Hydrovac.
Jerry

I think a hydro boost is a great idea.
However I think you'll find that a master cylinder well sized to your wheel cylinders will come from a say late 70's and 80's medium duty truck and the hydroboost that comes with that is a larger version than you probably want/need. Those larger Bendix "Hydromax" I think they're called have electric pumps for backup if the engine were to stall/die. I've had a truck with one and driven a few more, they sure work but not as refined and smooth feeling as the common hydroboost that you find in pickup sized trucks.

I would sure consider hydroboost even without power steering. I have both on my 2 ton and it's great. But for my 1 ton I plan to run just a small PS pump, a TC pump I think is the model, to operate the hydroboost and keep the manual steering.

My truck has single rear wheel cylinders. The spare later rear i have has dual cylinders.
I need to find all these cylinder sizes. Seems some old catalog digging is in order.

Does your truck have the original rear end in it? What size brakes does it have?

I might be able to get you the displacement of your 'vac if you give me the model number.

That way you know what to look for.

It has the original rear as far as I can tell. I'll have to crawl under it tomorrow for sizes and numbers. The vac is pretty rusty, so not sure if I'll find numbers, but thanks.

So, the fronts are 14x2ish? The rears look like 15x3, with single wheel cylinders.

The Vac I could not find any numbers on, but the cylinder portion looked like 1.25 od?