Vacuum operated wipers

[Joe Flanagan]

I was just looking at the control for my wipers, the thing that's mounted up under the dashboard. There is a 1/4" hose attached, which runs through the firewall and into the engine compartment. There is a fitting on the top of the intake manifold that matches the fitting on the end of the hose. Looks like that's where it goes. But I'm aware that the wiper system is also connected to my fuel pump, which does dual action for both fuel and wipers. I checked my manual but it seems they only cover electric wipers. Does anyone have an exploded diagram of how this is all put together? Thanks.

[TodFitch]

It is my understanding, never having had a vehicle with this setup, that the hose from the wiper would go to the fuel pump and then a separate hose would go from the fuel pump to the manifold.

Basically, the vacuum pump side of the fuel pump acts as a pass through when the manifold vacuum is sufficient and pumps when the manifold vacuum is insufficient. Consider it as a booster pump for the vacuum.

Now, as to which port on the fuel pump should be connected to the wiper and which to the manifold I could not guess without playing with the pump. I would think that if you had the engine running and no hoses on the two ports you could put your finger over each (or connect a vacuum gauge) and see which side is being sucked on. That would be where the hose to the wiper motor should attach.

[Joe Flanagan]

Consider it as a booster pump for the vacuum.

They do call it a fuel pump with vacuum booster so you must be correct.

[Plymouthy Adams]

the vacuum booster pump is a must for operation of vacuum wipers in hilly country..as the load on the engine climbing a long grade will require more fuel (open throttle, low speed condition) thus no or too little vacuum..heavy acceleration will give you the same effect...the early fuel economy/miser guages (remember the little yellow economy light) this was just a indicator showing that your engine speed bsed on relation to the throttle plate position was less than x vacuum resulting in wasted fuel..

[oldmopar]

here is some good info on how they operate

Wipers

[Joe Flanagan]

Excellent. Thank you. Just what I was looking for.

[oldmopar]

That is a great site below is a link to all of what they have on line. The 1st link the "master service tech" answers many questions that have been asked on the forum

http://www.imperialclub.com/Repair/Lit/index.htm

Edited December 27, 2009 by oldmopar

[bearheart]

A tip for slow vac wipers: Back in my old days when the wiper wasn't working very good we would put a few drops of light oil in through the opening and it would lube/swell the seals to make it operate like new again.

[greg g]

A vacuum canister like ford and GM used to have under the hoods to run heater controls and such, spliced int the line also helps. You can get 10 or more swipes out of your wipers even with the pedal to the metal.

[Greenbomb]

What years and models of Ford and GM had the vacuum canisters? That sounds like a slick idea.

Flo

[Bobtjr(dale)]

What years and models of Ford and GM had the vacuum canisters? That sounds like a slick idea.

Flo

Guys, I am planning to use a vacuum canister from an s-10 they are a small

sphere about 3.5 inches in diameter. It will hide under dash right beside the vacuum motor. In an 80's s-10 the heater controls are operated by vacuum.

Your local parts store has replacements for $20. or less.

5 years ago I bought one for $14.00.

Also I am adding a one-way valve to help preserve vacuum in the ball. So that when the motor has a vacuum loss, ie... climbing hills the reserve is kept.

Dale

ps. I have done this before it works.

I believe grumpy Don C. has done this one as well.

[Bobtjr(dale)]

I agree totally about adding a light oil to the vacuum line.

I use air conditioning oil its designed to condition rubber not destroy it

thanks Dale

[TodFitch]

Guys, I am planning to use a vacuum canister from an s-10 they are a small

sphere about 3.5 inches in diameter. It will hide under dash right beside the vacuum motor. In an 80's s-10 the heater controls are operated by vacuum.

Your local parts store has replacements for $20. or less.

5 years ago I bought one for $14.00.

Also I am adding a one-way valve to help preserve vacuum in the ball. So that when the motor has a vacuum loss, ie... climbing hills the reserve is kept.

Dale

ps. I have done this before it works.

I believe grumpy Don C. has done this one as well.

I picked up one of those 3.5 inch diameter vacuum reservoirs and had it on the car for a little while. It did not have enough capacity to make much difference and the darned thing rattled under some throttle change conditions. Just enough noise to be annoying.

I am considering making a reservoir from scratch with some PVC pipe that would be larger. But I haven't decided where I can hide it yet. Maybe in the windshield header area (my wiper mounts above the windshield). The one-way/check valve could be mounted elsewhere so if it rattles I don't have to listen to it.

[Don Coatney]

Dale

ps. I have done this before it works.

I believe grumpy Don C. has done this one as well.

[greg g]

just look uder the hoods, looks like a jusice can with the vacuum lines attached either on the firewal or the iner fender. VW's ad Audi's also have a plastic one bungied to the under side of the hood on a lot of 90's stuff. Looks like a ping pong ball storage tray.

Jeeps have a plastic domeshaped one behind the pass side headlight.

[martybose]

I bought a commercial power brake vacuum canister similar to Don's, and found a place at the lower right end of the firewall that is triangular shaped under the passenger footwell. There's a vertical body brace there, so I bolted the canister to the back side of the brace. There's a large hose to it from the intake manifold, and a small one that goes to the wiper motor. It works well, and is practically invisible.

Marty

[Bobtjr(dale)]

Beautiful installation,

Thought I remembered seeing the cannister in ok.

However I have been known to have sometimers:rolleyes:

Dale