Fuel pump with vacuum unit queston....

[BobT-47P15]

From earlier discussions - there is one model of fuel pump that had an

additional vacuum chamber on the bottom to give boost to the wipers

when in hilly terrain.

A previous quote - {" 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."}

Was this pump with vacuum chamber used as standard on certain years

or models, or was it more of an option. Or perhaps purchased at the

parts store later? I don't see it mentioned or shown in my parts

manual. Thanks.

[Joe Flanagan]

Bob, my 49 Special Deluxe came with it. The chamber for the wipers sits on top. I've seen other 49 Plymouths with it as well. What you quoted describes my understanding of how they work: Primarily off vacuum from the intake manifold, then off the pump when the vacuum from the intake collapses.

[blueskies]

Bob-

I don't know the years these were used either, but my '50 had one, and I'm assuming it was original equipment...

(reload for pic)

It had hard lines from the pump up to the manifold and firewall for the wipers.

You can just barely see the lines in the top of this pic, one of them does a 180 bend and goes into the intake manifold, the other goes up and out of the pic to the rubber wiper line that runs through the firewall.

One more

Pete

[Johnny S]

The AC number for the pump Bob is 9418. There are a couple other numbers that cross as well. One version has a glass sediment bowl (earlier model) and the newer models do not. I've actually seen (and have one) other version that works as well but don't know off the top of my head what the number is. Could check it out if you are interested. Here are the numbers I usually look for: 1523670, 1523648, 9418, 506x, 506. The first two are casting numbers .. sometimes they are listed with that only. The last two .... I think the 506x is the version with the sediment bowl and the vacumn assist. I'm not quite sure on the one that is just "506" it may be a version without vacumn assist. The standard pump number is 588 for the replacement OEM non-vacumn pump.

[james49ply]

I put one on my 48, got it from ATLAS, pricey, but helps a bit, need to get a good wiper motor and it will work all the time. I put one on a 49 Buick, wipers work even under hard acceleration.

[Brandon S]

Was considering getting one of these pricey things but looking in the Master Parts List also see they have a different heat shield, "bracket" and "insulator" which who knows where that can be found?  So this is more for assisting with the wipers than pushing more fuel to the carb?  The latter is my problem with my mechanical- got one from Bernbaum but it wasn't pumping to keep the float bowl full enough to run so found a NOS AC one that's coming in but wasn't cheap either.  I hope it's not a worn cam lobe. 

[greg g]

might be a clogged filter on the pickup in the tank.  Have you done the standard fuel flow test as outlined in the service manual?  What is the condition of the small piece of rubber fuel line between the front crossmember and the pump inlet?

[Brandon S]

Thanks for the reply Greg- all new lines- stainless fuel and rubber flex hoses.  Have a borrowed air compressor so going to try.  Coated the tank in Kreem and don't remember a strainer in there...

[desoto1939]

Here is a good one for you all:  The 39 Dodge/Desoto and Chrysler all had electric wiper motor. The 39 Ply stillretained the vacuum wiper motor.

 

Some point in time after 39 I think they all went back to a vacuum wiper motor, do not know why. Can anyone verify a year after 39 when they went back to vacuum.

 

Rich Hartung

Desoto1939@aol.com

[james curl]

The 41 Dodge luxury Liner that I took my engine out of had factory turn signals and electric wipers.

[_shel_ny]

 

 

Some point in time after 39 I think they all went back to a vacuum wiper motor, do not know why. Can anyone verify a year after 39 when they went back to vacuum.

 

If you are into jig saw puzzles, this may help.