Packard Forum Index » Post-War (1946-54)

Does it take a lot of force to move the arm? I remember after putting mine back together I tried the arm and there was a lot of resistance. I almost thought I put it back together incorrectly. Really had to bear down on it to move it.

the only way i can move them is to put the pump in the vice and use channelocks on the arms to get enough leverage. Both pumps take about the same amount of force.

Easier way and safer is to put the contact pad of the arm in a vise and move the pump. Channel locks if they slip can score the contact pad. Holding the pump yoiu get plenty of leverage plus you have some fingers free to cover the ports toc heck for vacuum/pressure

I went back out tonight with a plan to rebuild the early pump.

But then i found the kit doesn't fit EITHER pump.

So i started at the basics. I took the mighty vac and found it took very little vacuum to instantly get fuel from the line. No Problem there.

Rolled both motors around so the cam lobe was pushing the pump out and compared, both being pushed out about 3/4" from the block without forcing it in. (Must have had the lobe on the opposite side for other installs, never felt resistance.)

Took both pumps apart. Had trouble with the new one and set it aside.

Took the early apart, and it was very clean and diaphragms very good condition with some writing on them. Had to be rebuilt at some point, maybe 10-15 years ago when they did the first restore.

Worked it on the bench and easily putting out 5-6 psi bench testing. Put it back on the car (no gaskets or spacer, test fit.)

Rolled it over, little bit of air coming out of vacuum pump exhaust, maybe 1 psi pressure, very little on the fuel pump.

Thought for a minute and put some fuel in the carb bowl, then hooked the fuel line up to the fuel pump inlet.

Fired the motor, instantly spraying fuel everywhere. EVERYWHERE.

I've lost about 2 gallons of fuel over the last couple days to these experiments. Ugh. Love the lemon flavored simple green.

My theory is that both of these pumps are weak, but it didn't show because there was always fuel in the carb bowl to fire the motor, which cranked the cam over fast enough once it fired to start pumping.

I think that my real problem wasn't that the fuel pump wasn't pumping...it wasn't pumping enough at a slow roll over rate to get fuel moving in a completely dry system.

I will likely exchange the fuel pump that's not in pieces even though it is working, for the piece of mind of a new fuel/vacuum pump that will likely move some fuel, even if it's just the starter rolling things over.

In the meantime, i'll finish buttoning up the tranny linkage and getting that filled the rest of the way and hooking the new coolers up to it so i can let it run for more than a split second without worrying i'm going to hurt something back there.

Thank you ALL for the advice, I've certainly learned more about the fuel/vacuum system on this car than I intended to. If all goes well and you guys make it to Warren, i'll buy a round of beer!

Talked to MM today, and they confirmed that any pump would work and pump, and there should be no difference in vacuum or amount of fuel pumped, etc, but they can't confirm arm action throw length or anything. I told them my setup, and ordered a pump for the 50 style (that uses compression fittings for everything vs some rubber vaccum lines.)

Saves me from putting the later pump i kind of got frustrated with together for a core, since i can send the 50 back in as is.

Thanks all for the help and tips! I feel foolish i didn't try to use the engine to move the fuel sooner, i guess i assumed that the starter would be enough to start the process.

" i guess i assumed that the starter would be enough to start the process."

Yes, it should have been. That's usualy the way fule pump pressure tests are conducted using a gauge. Using starter only.

EDIT: Note that the manual probably says to run the engine. I get pressure readings just fine by just using starter.

I'm betting when the new pump gets here, it'll pump fine without firing the engine. Probobly wear in the valves in the pump somewhere? Diaphrams seemed nice. Did notice that the pump didn't hold pressure that well in tests, but i don't know if it's supposed to.

Cortcomp said I told them my setup, and ordered a pump for the 50 style (that uses compression fittings for everything vs some rubber vaccum lines.)

I've never seen use of compression fittings on a Packard except for some Bijur chassis oiler lines. I suspect you meant flare fittings?

That is exactly what i meant, sorry. The inverter flare type used on brake lines etc, correct? I meant screw in hard line fittings for vacuum and fuel, vs just slip on rubber fittings for vacuum.

I'm always using the wrong fitting terms, i'm not that well versed. I wish AN would have been the standard since the get go and nothing else had been made...i always have to bring fittings to the parts store so they know what i'm trying to do.