The Stovebolt Site Forums The Shop Area Engine Shop Vacuum Routing Options

I needed to replace my fuel pump so decided to get the double action vacuum pump type to help with the wipers.
I have made the PCV mod to my otherwise stock 216. I also added dual mc vacuum assisted front disc brakes.
I can think of several options to connect up all the vacuum lines this combo needs.
1. Wipers through the pump to manifold. PCV direct to manifold. Brake booster direct to manifold. So I need a triple-tee at the manifold for this.
2. Like #1 but route the brake booster through the vacuum pump through a T fitting with the wipers. My thinking is that the brakes might get a benefit from the vacuum pump in low-manifold vac conditions?
3. Like #2 for brakes and wipers but gang the pump outlet with the PCV and run a single line to the manifold. This simplifies the routing to the manifold. Some concern of PCV gunk getting into the vacuum pump, but theoretically that shouldn't happen.

The truck is not running yet so I can't test the options. Anyone solve this combo before?

Your are going to need to install at least one additional 216 engine in the truck to be able to create enough vacuum to operate everything that you have hooked up.
You can look for an electric vacuum pump on a diesel engine in a junkyard. That is if you are running 12 volts.

You could add a vacuum reservoir, as was used on some trucks A-D & ND trucks with vacuum:

- wipers
- two speed rear selector and speedometer selector
- PCV
- hydrovac

I found in the FAM a reference to RPO 217 engine pos vent., which shows a three way at the manifold per my #1 plan, but I cannot find anything on a reservoir.... Like how large, where to put it, hookups, etc?
I am converted to 12v already, but do I really need more vac than a healthy 216 can produce?

The PCV Valve will take away about 2 inches of mercury (no more than that) all by itself. That is if you are using a V-237 valve. Its as low as is practical for that engine. I think you are asking way too much of that little engine and you will need to add something else to get your wipers to work. THAT is where you will notice a problem.

I cannot find reference to a vacuum reservoir in a Chevrolet Shop Manual (48-52 manual). There is a reservoir in my 54/55 2-ton GMC, but I know nothing about its operation - sorry.

Maybe a big-truck owner/mechanic will off explanation/advice. My guess is that the reservoir tank is about 1 gallon in size.

Here is another option.
You could go with a Electric Wiper Motor works on 6 or 12 volts.
And switch back to a single action fuel pump.

Here is a 1954 Chevrolet Pickup Electric Wiper Motor 6 volt only.
I do not think it will mount in your 1951 pickup though.

Deve, I was following your PCV work and bought the V-178 before your testing concluded on the V-237!
Based on all the replies here, I may just go to elec wipers after all - seems much easier (and more effective) than a reservoir system. I haven't checked out my wiper motor yet - it wasn't connected when I bought the truck so it may be junk anyway.
Having said that, would it still make sense to run my power brake booster through the fuel/vacuum pump to essentially offset the draw of the new PCV?

Sorry about that. Better late than never. If you are not experiencing oil sucking into the lines, and most don't you are okay with that one, just replace it someday with the 237. Electric wipers are just prudent if you drive it a lot and that would solve your problems. I do not know the answer to your last question.

A vacuum canister, referred to a "tomato can", is what you can use. I installed one on my 59 3100. It has 2 ports, one side is connected to the engine and the other to one of your components needing vacuum. You can also use a "T" fitting in the line off your component to help another component. I'd recomend hooking that up to something not used all the time, such as wipers and maybe an optional windshield washer. I have an extra if you're interested.
I'd hook my booster to the engine.
Does anyone know if there is a fule pump made for a V8 that has a vacuum port like the old 235 pumps?