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M38 fuel pump

Posted: Wed Nov 30, 2011 7:37 am
by henrydes
I have a M38a fuel pump on an M38 with the machanical primer lever. I would like to remove the lever arm as it gets in the way of the tubing for the windshield wipers. Is there a safe way of doing this so as not to damage the pump.

Posted: Wed Nov 30, 2011 9:51 am
by wilfreeman
I think I read take it out and plug it somewhere, but I'm not positive. I'm sure Wes will know and will chime in shortly. I have a pump that is missing the lever - I would like to rebuild it and use it, so I'd like to know the answer too.

Posted: Wed Nov 30, 2011 11:13 am
by wesk
It's a very handy item if you let the jeep sit a lot. You are the first person to complain of any interference issue with it. The pump would have to be removed and partially disassembled to remove the lever and it's associated parts.

In the photo below you can see that the front vacuum fitting is angled towards the engine and the tube should run between the block and the exhaust manifold. There should be no interference issue at all.

Image

Posted: Wed Nov 30, 2011 1:42 pm
by Bretto
I have a 3a fuel pump so dont have either the stock pump or a primer dash pump. Do they do different tasks?

Posted: Wed Nov 30, 2011 2:03 pm
by evanso1975
As I understand, the dash primer pump was for priming the fuel in cold weather. Willys stopped fitting the dash primer pump to the M38 around December '51 (maybe that's why the M38A1's had the lever?). The M38 fuel pump didn't have the lever on it.
There should be no interference issue at all.
You may possibly have a clash if you're trying to fit an M38A1 fuel pump to an M38 engine. The original post isn't clear as to the jeep in question. The fuel pump I got for my M38 is an M38A1 pump, but somebody hacksawed the handle off just near the pivot. :x So I can't confirm if there's a clash or not.

Posted: Wed Nov 30, 2011 3:44 pm
by wesk
The dash primer was for cold weather priming directly into the intake manifold. This system although factory installation was discontinued mid M38 production was very often installed in the field on vehicles assigned to cold climates and was a required part of the arctic heater kits.

The carb mounted hand pump lever was for refilling the carb bowl after the engine was not run for long periods.

Although the M38 didn't originally come with the hand lever fuel pump it was often used as the superseding pump in the field by the Army.

Yes if it's an M38 it can be a slight issue but is easily worked around by using the fitting used on the A1 installation and bending the wiper line accordingly. Or you could bend the lower half of the handle outwards away from the pump.

Image
M38 engine

fule pump

Posted: Wed Nov 30, 2011 4:24 pm
by henrydes
On my question about removing the lever on the fuel pump because of interfearence to the vacume lines...look at your picture of the left side, the vacume lines are outside of the manifold...This pump is on a M38????

Posted: Wed Nov 30, 2011 4:29 pm
by wesk
You must have posted without seeing my second post above your last post! :wink:

Go back to your original post and edit it to remove that A after M38.

I have listed your reasonable options already above.