Fuel pump question.

USCGmatt · Post by **USCGmatt** » Wed Aug 20, 2008 5:57 pm

Is it safe to run the engine with just the fuel pump hooked up (vacuum side ports left open) or will this ruin the pump? My M38 has been civilianized and I am slowly bringing it back to stock. My old pump (electric) went bad so it needed changing. Thanks for the help.

Matt

Post by **Ryan_Miller** » Wed Aug 20, 2008 7:49 pm

I would think that should be OK as long as it does not suck anything into the pump.

Post by **wesk** » Wed Aug 20, 2008 10:00 pm

If you have the military distributor installed then you should connect the inlet side of the vac pump to the wiper "T" and connect the wiper "T" to the distributor and wipers. Then connect the outlet side of the vac pump to the port on the rear end of the intake manifold. This will at least insure proper ventilation for the distributor.

USCGmatt · Post by **USCGmatt** » Thu Aug 21, 2008 5:56 am

Thanks for the quick replys. The only military accessory as of this point is the pump. Thanks again

Matt

Post by **wesk** » Thu Aug 21, 2008 8:13 am

Then do not plug the ports. Use the axle housing style vent caps to keep dirt out and allow air to flow.

The vent cap shown here in the middle flow through vent should also be used in the two lower vac pump ports if they are not to be used.

SteveJ · Post by **SteveJ** » Mon Aug 25, 2008 1:05 pm

Hello Wes

My pump does not have a priming lever. Was it usual to see one on the M38?

thanks

Post by **wesk** » Mon Aug 25, 2008 5:40 pm

No. The dual fuel/vac pump priming handle showed up originally on the M38A1. It will fit either jeep and was often installed as a replacement in the field in both jeeps.

USCGmatt · Post by **USCGmatt** » Wed Aug 27, 2008 5:28 pm

One more question, well hopefully. I started the jeep up and it ran great for about 5 min then fuel sprayed out the vent on top of the carb. I noticed the fuel in the filter after the pump looked like carmel but not thick at all. I pulled the carb apart and found the float stuck. I then cleaned it up and reassembled the carb. I used an electric pump to suck fuel through the pump and filter, after about a pint the fuel looked good. But the float still sticks unless you tap it every little while. Is there some sort of presertive in the pump for storage? I bought this pump from Midwest about 6 months ago and it has been in a box until install. The carb was rebuilt at the same time the pump was purchased (from Midwest also). Thanks for all of the help.

Matt