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I just noticed a auction for a M38 vacuum wiper pump. Great idea because none of my vehicles with a fuel pump assist works worth a darn. The wipers all work fine until you step on the gas a dump the manifold vacuum. Has anyone used one of these? Sad part is they want more for this pump than a good electric wiper motor. You could put the pump under the dash and never see it. Keep the original look that way. Any experience here? Is it real or bogus on a Jeep? John

24V pump??

Doesn't say. I did a search on ebay and found another that was for a WW2 truck. Made by Trico. It has a electric motor similar to a heater blower motor powering a vacuum pump. Only 250.00! John

Vacuum wipers work more the adequately as long as all is in tip top shape. If the paddles are gone in the motors they will not handle heavy windshield rain, wind or snow loads and they will always quit when you accelerate and reduce the manifold pressure. If the jeep is a daily driver and good visibility is needed then either maintain the system tip top or switch to electric. The addition of an electric vacuum pump will not guarantee the wipers will function adequately for your needs. If the wiper motors are weak the additional vacuum will make them faster but they won't handle heavy loads. The best remedial effort you can make is to rebuild the motors and the vac side of the fuel pump and add a good size vacuum reservoir to your plumbing. As a rule of thumb if you can easily operate the wipers manually by just rotating your wrist and not using your forearms then the paddles are too worn.

Keep in mind that you want 10" of vac at 200 RPM and 12" of vac at 1500 RPM. Since she idles around 600 you should always see 11 to 12" vac.

I installed a set of electric 24V Bosch electric units with acceptable results.
They are a bit noisy but at least I can see....
Pete has these available on his site : http://www.debellajeepparts.com/m38spec.htm



They will require you to furnish an adapter as the mounting hole span is wider than the stock spacing (for the Trico unit).

As a single speed and when coupled to a "Momentary ON"-OFF-ON switch prove effective on my frequent driver. These are available at Saturn Surplus: http://saturnsurplus.com/electrical/on-off-moment.htm



If your not to concerned with stock appearance, the contemporary wiper arms shown below work very well with the torque of the Bosch units.
These are available at Saturn Surplus: http://saturnsurplus.com/vehicles/sat-51-062c.htm

Bosch in my opinion makes the best electric wiper motor, no doubt. The english had poor Lucas lights and the slogan was: " a gentleman does not motor about after dark". I wonder if the Jeep slogan should be: " just don't drive in the rain". I tried your tip Wes, on adding some motor oil through the vacuum inlet port, and it helped greatly. Not only are the vacuum motors wimpy, so are the stock blades and arms. Modified's method for a real bad weather Jeep is the way to go. Thanks, John

Lucas electrics-On-Bright-Dim-Off. In that order when you flip a switch..
51 Healy Sprite back in about '67.