Auxillary Vacuum Pump for my 56 Buick

[Beemon]

The electric wipers were pretty underwhelming, too say the least. Not only did they sweep too much, but they wouldn't even sweep the window when it's dry... I know it's not really a test of function, but the vacuum wipers sweep the window dry if that's anything to go by. So, I was doing some research into different electric vacuum pumps, but it seemed they would all tax the generator a bit much. Then I started looking at diesel vacuum pumps and that's when I found it - a 1983-92 Ford vaccum pump, still V-belt driven. Out of the three trucks at the local junkyard, only one held vacuum. They said I could return it if it was garbage, but it actually held 23" Hg by itself. This should be more than enough to hold the wipers. I was even thinking the power brakes, but I'd rather that be on intake manifold if the pump ever fails. Maybe I'll tee into the power brakes line with a 1-way valve so if the pump fails, it won't loose vacuum, but I'm not sure what kind of havoc that would play also being tee'd into a line that's already tee'd into the manifold...

 

Anyways, I've been thinking about where to mount it. The bracket as it sits would need some modification to fit the engine, but I'm thinking water crossover bolts. It fits in line perfectly with the generator, and that will probably be my test spot, but that's where factory AC goes. Likewise, I wanted to put it under the power steering pump where it's out of sight, but it's pretty tight  in there. It's not heavy and was only held on by two bolts, I figured I could modify the bracket so it's fixed, and then tighten the belt with either the P/S pump or generator. I almost gave up on my timing cover swap, but now it's back on again.

 

[NTX5467]

Olds 307 (5.0L) V-8s from the mid-to-later 1980s had belt-driven vacuum pumps, too.  It seems that those engines were so "under-producers" that they always operated at too-low intake manifold vacuum levels, so something extra was needed to keep the a/c coming out of the proper dash vents.

 

NTX5467

[Beemon]

Willis, I saw plenty of these on the 80s wrecks out there, as well. The differences between them is that this is a vacuum pump and the others are smog air pumps that have some type of filter or something in them. At least that's what I gathered from their almost alternator looking case and construction. I'm not sure about those smog pumps, but I'm pretty sure that the vacuum pump I found is also being made new still. I really don't have any information on cars of that era to really make a formulated opinion, but I think this application will exceed my expectations.

[NTX5467]

The A.I.R pumps have valving and manifolding which end with the exhaust manifold.  I do remember some had belt-driven vacuum pumps, but I'll have to research that some more.  ALSO, on some diesel medium-duty trucks I ran across something called "vacuum generator" which was a small mechanism that had one vacuum line "in" and one "out" that went to the a/c system to work the actuators.  I'll have to research that, too, as I sold a few of them back in the 1990s. 

 

NTX5467 

[Barney Eaton]

Why not try a vacuum tank first.....many late vehicles have them, probably to stabilize the operation of cruise control.

All 3800 cars also have a vacuum check valve. in the schematic below 1 comes from the engine...the lump between 1 and 2 is the check valve, one leg going to the vacuum reservoir and the other going to the heater controls

You could do a test without any hard mounting, when you are satisfied with the operation, the tank would be mounted somewhere it didn't show.

Edited May 20, 2017 by Barney Eaton (see edit history)

[Beemon]

Hills where I live are plentiful, I don't think a vacuum tank will hold more than 30 seconds before it's depleted... plus where I'll be going to school is on the other side of a busy mountain pass followed by a steep gradual slope (downhill going, uphill coming back) and then rolling plains. Coming back from orientation was the first time I'd seen the old girl puke green after we made it to the top of the steep incline before the start of the mountain pass. Vacuum tank works fine for brakes because they're not constantly on and they can replenish before you use them again, especially when vacuum builds on deceleration. But wipers are on all the time, I don't think I'd see a noticeable performance gain when driving 45 minutes up a mountain.

[Barney Eaton]

On another subject, flush your brake fluid while you are getting the car ready for travel. Where you live this could be critical. Brake fluid absorbs around 1-2% moisture per year and maybe more in your damp climate.

1.3% moisture lower the boiling point of DOT 3 by 100F.  Using your brakes on those hills can be tough on brakes, so don't boil the fluid.  Change it

Found chart below, hope it is large enough to read.

Edited May 23, 2017 by Barney Eaton (see edit history)

[NTX5467]

For what you describe, it appears that either the booster fuel pump or a full electric situation are the only real choices.  Perhaps this is a market that Newport Eng might be interested in, with the particular wiper system you have?

 

NTX5467

[Beemon]

On 5/27/2017 at 10:09 AM, NTX5467 said:

Perhaps this is a market that Newport Eng might be interested in, with the particular wiper system you have?

 

I wouldn't bother with them again. Although the said they would fix the sweep of my wiper motor for free, they sold me the wrong motor for my application, and the motor is weak compared to a 56 Chevy motor and even the vacuum motor at full manifold vacuum.

[Airy Cat]

Just don't drive in the rain.

[Beemon]

Lol ok

[mcdarrunt]

I'm a fan of vacuum wipers also. They take up just the room under the dash that was designed for them, all linkage is factory designed, and they have an infinite number of speed settings. I even have a delay switch (valve) on mine that is foot operated. My choice of pumps is one from a Mercedes diesel that can be mounted anywhere and then just a single hose ran to the vacuum motor. There was a heavy wire, maybe 8g, on the Mercedes but the pump was way back under the seat or behind the spare tire. When mounted up front a 10g wire is fine and my 63 amp alternator has kept up without problem. If I had radiator fan(s) or a bodacious sound system I'd probably go to the 100 amp alternator---$60 on ebay. With this set up you can pull a loaded trailer uphill with zero change in wiper speed or watch a drive in movie in the rain without the engine running.

Edited July 19, 2017 by mcdarrunt
omitted word (see edit history)

[Beemon]

Thanks for the tip! Unfortunately, the last drive in theater nearby was torn down and turned into a yardless housing lot exactly 7 months before I got my Buick back on the road. I've more or less given up on this concept after my whole engine debacle, but if I revisit it, it would probably be electric for ease of operation. There's no good place to put the V-belt pump unless you make a bracket and stick it under the PS pump, which there isn't much room for unless you put it almost towards the battery - or put it where the AC is supposed to go. The only issue with electric is that you need to dump the generator, etc etc, then loose the factory safety feature for the starter. I suppose a Powergen would solve all problems, but they're $$$. Anyways, what year Mercedes pump do you recommend?