Vacuum can

[Lawson Cox]

I have read several places that you can mount a vacuum can between intake and wiper motor to prevent wipers from slowing down on acceleration. What kind of vacuum can? Where do you get one? Where do you mount one?

[V12Bill]

You will also need a check valve in the vacuum can to keep the vacuum in the can when you step on the gas and the manifold vacuum decreases. Otherwise a plain can will not be of any use. The vacuum can was standard on 1947 & 8 Lincolns and optional on 1947 & 8 Ford and Mercury.

[donald1950]

had one on an oldsmobile one time. a foot in diameter and 2 feet long, inside the frnderwell, front wheel. had a check valve on it. worked fairly well but on a long hill it still ran out of vacuum and took a long time to build up vacuum again. if you are having that much of a problem i would consider a small vacuum pump with a on/off switch to boost wiper vacuum as needed. on one of my 50s i had a dual action fuel pump that was the best answer, but i doubt one is made for the pre 49 motors. i have a 12v unit that i am not useing. its a never used Trico electro-vac unit. i know nothing about it or how it wires. one of the wiper motor rebuilders might know about it. it would have to use a 6v to 12v step up device to power it. if you are intrested it would cost you shipping only. the only date i can find on it is "1954 patent pending". it has labels and tags on it but i have no installation wireing information. the patent numbers on it could probably be reasearched to find more info on it.. don

[Dave/Green Bay]

Lawson:
We took one for a Jaugar XKE out of the scrape yard already had the check valve. Dave/Green Bay

[Charlie ny]

LC,
I test fuel pumps after rebuilds this includes double action fuel pumps.
To do this I use an 8BA fp stand and push rod. I turn the motor end of the
pr down to run in the early bushing. The intake on my test motor is a garden
variety iron '40 pass.
Depending on the previous life of the double action pump you use the vac
inlet and outlet might require changing. Usually there are 2 inlet and 2 outlet locations
so you can choose accordingly.
I drilled and tapped the side of the 8BA stand for a copper elbow which doubles
as an oil fill and breather.
Piece o' cake.
Charlie ny

[Old Henry]

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[From this thread: https://fordbarn.com/forum/showthread.php?t=83364]

I know a vacuum reservoir tank for the windshield wipers sounds like a good idea and Ford even manufactured and sold one as an optional accessory for the 46-48. I thought it sounded like such a great idea that I bought one and installed it. I have since taken it back out. Why? Here's the rub: A reservoir tank sounds like a good idea, the "theory" being that it would "store" vacuum so that when you accelerated or were cllimbing a hill and lost the constant continuous vacuum from the engine that the reservoir would take over and run the wipers until you let up on the gas and restored the manifold vacuum, right? Well, yes. That part worked pretty cool. When I mashed the gas, for whatever reason, I'd get about 7 full swipes of the wiper blades on the vacuum stored in the reservoir before it was gone and the wipers stopped - about 7 seconds. Then, I let up on the gas to "refill" the vacuum reservoir to get them going again. Right? Wrong! Here's why: It takes the same amount of time to "refill" the vacuum tank as it did to empty it - about 7 seconds - during which time there are not only no wipers but no power because the gas pedal has to be clear up to refill it! So, what good did that do? None! All it did was make the wiper operation "sloppy" and out of control. I decided I'd rather go back to having total control of the wipers by feathering the gas pedal just enough to keep them going if that's what I wanted or let then stop if I didn't need them constantly then, when I needed them, I could get them started immediately again by letting up on the gas pedal just for an instant for a quick swipe of the wipers then back to feathering or none until I needed a quick swipe again. I can see why Ford did not install the vacuum tanks as standard equipment. Owners would have soon bypassed them and gone with the strictly "manual" vacuum control.

The only way I can see a vacuum reservoir working is if it was hooked up to some huge vacuum port that would have to be made in the intake manifold at least as big as a power brake port so that the tank could be "refilled" immediately with a quick lift of the gas pedal while the tank could run the wipers for 7 seconds while the engine vacuum was gone. The Ford tank actually came with a larger hose to run from the carburetor vacuum port to the tank than the standard size hose from the tank to the wiper motor. But it wasn't big enough to really work.

[V12Bill]

The Ford vacuum tank is half the size of the Lincoln tank. The Lincoln tank is about 10 to 12 " in dia. and the Ford tank appears to be half a Lincoln tank. I can get about 20 to 24 wipes of the wiper from my tank with the engine off. I have driven in the rain, but did not pass any cars or climb any hills. (flat in NJ) I guess the tank would work as advertized, but don;t purposely go out in the rain to try it.

[Bruce Lancaster]

A couple of devices I know of...no practical experience with them to report, though.
Stewart warner used to sell a device called the Electrovac...they turn up at the fleas, and I have a couple. Small vac pump with pressure drop switch, an electric motor about the size of a heater motor spins the thing.
Smart 1940's economics, there...save the cost of electric motor by using vac wipers, then add electric motor to supply more vacuum...

1980's GM hardware, probably exists in other lines...Corvettes and small-engined X cars got a electric vac pump with switch to keep brake booster happy when engine was running at a low vac level...one switch plugged into a hole in booster, which would require some adapting to make it workable for us, a few had an inline switch in the vac hose leading to electric pump, which would be easier to adapt to a wiper system. This stuff could be hooked to a can...remember that in the modern cars, the brake booster canister served as a reservoir.
Typically, the electric pump lived under the battery. Hidden in a fender in Corvettes... the systems can be spotted by the existence of 2 rather than 1 big hose on the brake booster, and of course following the hosiery will lead you to the electric stuff.
I also saw one junked Cadillac, one of the troublesome aluminum V8 ones, that had a mechanical vac pump with a little pump like a smog pump driven by a tiny auxiliary belt off the engine. This stuff should still be findable and dirt cheap. Interesting science experiment for anyone with 12 volts...

[woodypecker]

GM used large soup can size tanks in the 80's

[woodiewagon46]

I once was given a 6 volt vacuum pump that I installed in a car. I piped it into the wiper circuit and used a small canister as a reservoir. It worked just like an electric wiper and never stalled. I don't know what the pump was for I think it was for a boat but I have never seen one since. Anybody know where they can be purchased?

[paul2748]

Is your car 6 or 12 volt? If 12, I think a electric replacement is available.

[Brendan]

I had a 65 Ford that had a vacuum can that looked like a big soup can

[Old Henry]

Originally Posted by Brendan

I had a 65 Ford that had a vacuum can that looked like a big soup can

Originally Posted by woodypecker

GM used large soup can size tanks in the 80's

Those vacuum tanks were just big enough to store some vacuum for the vacuum operated heating and air conditioning dampers. Very low capacity and volume for very limited need. Certainly couldn't run vacuum wipers.

[Marvin/TN]

I think the best way to fix the problem is to check with New Port engineering. They have a bolt in 2 spd elect wiper conversion. You can't tell it has been converted unless you look under the dash.

[sturgis39]

Dodge and other cars used a vacuum canister as a fuel pump. The vacuum was created with a venturi in the engine lubricating system. Wherever you have flow you can create a vacuum. I think Dodge used the manifold vacuum for the wiper system.

I thought about installing one of those fancy high volume oil pumps and installing a line from the oil pressure gauge with a venturi and have it dump the intake manifold. This would produce a vacuum that would not be dependent on the throttle position.

I have not done much but thought about it.

The funny thing about the Dodge fuel canister system was that when you were low on oil the car would not run because there was no vacuum to suck the gas

[Vic Piano]

Lawson, I got two vacuum brake canisters from Summit Racing, I installed one in our '39 CS and one in our '51 F-1. They do a nice job of keeping the wipers going at a steady pace when you accelerate or back off the gas.

[4tl8ford]

The tanks can be made from a length 0f PVC pipe and two end caps and two check valves, an innie and an outtie.
Truck and trains have been using air tanks for years, so have many cars - Don't understand how one that didn't work should end them all.

[Lawson Cox]

All of the above sound good but apparently have limited capacity to help all that much. Thanks for every one's input.