vacuum wiper conversion

cuzncletus

cuzncletus

Senior Member
I want to convert my 39 Deluxe from vacuum to electric. If any of you are too young to remember driving vacuum wipers, you won't understand that you did indeed have to "drive" them. I had a stock '46 when I was a kid in the Blue Ridge Mountains and keeping snow and rain off the windshield going uphill was an art. Nostalgic, yes. Something I want to repeat, no.

Any experience with kits or dealers would be appreciated. I've already accessed several good dealers from this site and am looking to deal with others who support our cause.
 
If you are not able to find a "boutique" to get a motor from, here are a couple of cheap ones from WalMac:

12 volt: http://macsautoparts.com/early-v8-e...steel-a17508e12/camid/F30/cp/JS0R3CHL1077250/

6 volt: http://macsautoparts.com/early-v8-e...-steel-a17508e6/camid/F30/cp/JS0R3CHL1129687/

They are both universal motors that require some modification to mount.

Or, here are some others that you'll pay more for but allege to fit right in: https://secure435.hostgator.com/~dl...or&catalog_choice=All+catalogs&year_choice=39
 
I intend to run an accesory vacuum pump to solve this problem, with one line to the wipers. Does anyone know how effective this arrangement is?
Ah yes, uphill wiping is an art, downhill, you somtimes wonder if the wipers are going to stay connected.
 
Did you try adding a vacum tank with a one way valve between the intake manifold and the vacum tank and come out of the vacum tank to the wipers Mrv
 
Marv said:
Did you try adding a vacum tank with a one way valve between the intake manifold and the vacum tank and come out of the vacum tank to the wipers Mrv
Click to expand...

Think that's a good idea? You're not the only one. Here's Ford's promotional literature about such an idea:

45197873.jpg


Well, I thought it sounded like a good idea too so I actually searched for years for the stock vacuum tank Ford made for 42-48 cars hoping it would make my wipers less vulnerable to vacuum loss. I found one and was so excited to install it and try it out. The advantage it gave me was that, when I mashed down on the gas, like when climbing a hill, it gave me about 7 swipes of the wipers before they quit. The unfortunate surprise, however, was that, once they quit, it was about that long again after letting up on the gas before the tank was charged again to get the wipers going again. Darn. It seemed like such a great idea. I took the tank off and prefer to have total control over when the wipers wipe and when they don't. If they stop while going up a hill, I wait until the windshield is good and loaded then just let up on the gas enough to get them to wipe across once to clean off the windshield then carry on up the hill with WOT until I need to wipe again.

I've seen several suggest vacuum storage tanks. Although it seems like a good idea, I didn't like it.

FYI here's the stock vacuum storage tank I installed:

45197619.jpg
 
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Fe26 said:
I intend to run an accesory vacuum pump to solve this problem.
Click to expand...

The only vacuum pumps I know of are 12 volt electric pumps. If that's so, first of all, it wouldn't work if you're still 6 volts; and, why add an electric pump to run the vacuum motors instead of just replacing the vacuum motor with an electric one? Unless you just really like the sound of the vacuum hissss. You can actually get the electric wiper motors in 6 volt.
 
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On the vacuum tank solution. I would think ssize of tank would be deciding factor, too large won't work, too small no advantage, somewhere in between, but I don't know what size that might be.
Old Henry: what are/were the approx dimensions of the tank (orig) you installed?
Paul in CT
 
1931 flamingo said:
Old Henry: what are/were the approx dimensions of the tank (orig) you installed?
Paul in CT
Click to expand...

20" X 10" X 5". Capacity about 3.5 gallons. Size relative to the fender shown in promotional illustration.

I don't think the size would make any difference. Whatever time it takes to discharge it pretty much takes to recharge. The real bottleneck to recharging is the small vacuum port below the carburetor. The hose fitting to the tank is larger coming from that port than the fitting going to the wiper motor and larger than the port on the carb. (See illustration) I had a larger hose on that larger fitting but the vacuum to charge the tank still had to go through the small port below the carb. (See the reducer, part 17644, in the illustration.) It may be that if vacuum was accessed through a larger port on the manifold it would charge quicker and work much better. Someday I may try that.
 
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You can also rig the intake of a decent 6v or 12v tire pump to pull the required wiper vacuum. 8^)

Jack E/NJ
 
I think Old Henry has the rightidea. On some of the 70's Fords and maybe Mercs also, there was a vacuum reservoir mounted on the inner fender well. Because the 39 cars are difficult to replace the wiper motor (no good substitute), I tried one of these cannisters on my 39 coupe. It worked well. It was the size of a medium coffee can and kinda looked just like one. It had some sort of check valve. I mounted it under the front floorboard on the pass side. I only removed it when I decided not to travel in the rain anymore.
 
34flathead said:
howbout rolling up 2 or 3 extra feet of vacuum line under the dash to use like a small reservoir ?
rich
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Think about the volume of the vacuum chamber on a vacuum motor. I calculate it to be about 13 cubic inches. I get about 14 swipes (7 pairs - back and forth) from my tank which I calculate has about 1570 cubic inches of volume. I calculate the volume of a 1/4 inch hose to be .6 cubic inch per linear foot. So, to equal my tank, you'd have to have 1,308 feet of hose. And, although the volume may be equal, the friction on the insides of such a hose resisting the flow of air in and out of it would substantialy reduce it's efficiency and do nothing to solve the problem I had with not being able to charge the storage tank much faster than discharging it. Interesting idea though. Thanks for sharing.

(Edited to correct erroneous calculations previously posted)
 
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volume = pi x radius x radius x length ~ 22/7 x 0.125" x 0.125" x 12" = 0.6 cubic inches per foot of 0.25" id hose.

Jack E/NJ
 
Any number of diesel powered vehicles may have had a belt driven vaucuumn pump. I know my old LN8000 with V* Cat had one.
 
Jack E/NJ said:
volume = pi x radius x radius x length ~ 22/7 x 0.125" x 0.125" x 12" = 0.6 cubic inches per foot of 0.25" id hose.

Jack E/NJ
Click to expand...

Sorry, I forgot the old Pi R squared formula for area.

So, re-calculating for both the volume of the hose AND my tank (which I also messed up) renders 785 cu.in. for the tank divided by .6 cu.in volume per foot of hose requires 1,308 feet of hose to equal the tank. That's a lot of hose.

Thanks for straightening me out.
 
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Old Henry said:
The only vacuum pumps I know of are 12 volt electric pumps. If that's so, first of all, it wouldn't work if you're still 6 volts; and, why add an electric pump to run the vacuum motors instead of just replacing the vacuum motor with an electric one? Unless you just really like the sound of the vacuum hissss. You can actually get the electric wiper motors in 6 volt.
Click to expand...

I have two old belt driven 'Trico' vacuum pumps. I'm thinking of mounting one where it is semi-permanently engaged with the fan belt, then connecting the wiper vacuum hose directly to the pump.

The way I see it working is; as the fan belt is always moving the pump is always producing vacuum, therefore vacuum should be constant.
Is anyone running one, and if so, how effective are they?
 
The 1949-53 Ford had a dual diaphragm fuel/vacuum pump that would provide supplementary vacuum for the wipers. The top diaphragm pumped the fuel and the lower diaphragm pumped the vacuum. Dennis Carpenter has them for $175 but you might be able to find one in an older car junkyard.

There are some cheaper NOS ones on ebay right now..........
 

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