willysmjeeps.com

I posted this in my project thread, but figured it better to put it here.

I bought a fuel pump from EBay (https://www.ebay.com/itm/300844203386 ) and received it. The lever doesn't seem to move very much. Is there some sort of release pin or something I am missing?

Also, should I cap or leave the vacuum tubes open since I don't yet have wipers to run it to?

It's a good idea to not cap the vacuum portion of the pump. If you follow the vacuum plumbing properly you will still need to run all lines from the pump to the intake and the pump to the wiper "T" and from the wiper "T" to the distributor and from the distributor to the air cleaner inlet. You can cap the wiper side of the wiper "T" until you need to hook up wipers. The distributor plumbing insures the ionized (explosive) gases do not remain trapped in the distributor housing. Also helps with cooling the coil.

The manual primer does not move very much. The arm actuates a small piston-like device that pushes on the diaphragm. This is a new reproduction unit. You shouldn’t be missing anything.

Your link is to a civilian dual vac/fuel pump not a M38A1 unit with a hand primer.
https://www.ebay.com/itm/300844203386






This is a military M38A1 dual vac/fuel pump with hand primer lever.

Which one of these pumps do you actually have?

The civilian one. I meant to explain that it is the pump lever that is not moving, not the primer handle. Sorry for any confusion.

The pump lever is very hard to move by hand. Even snug in a vise(careful not to crack housing) it is very hard to move. I was testing vac pressure and had a tube as leverage so I could pump mine during testing

if I am in a hurry I clamp the pump's lever in the vise and pump the pump housing.

One item that always seems to get overlooked is the pump actuating cam at the front end of the cam. This cam will often be found worn down almost circular offering hardly any pump stroke at all.