Packard Forum Index » General

Our 1936 packard 12 cyl sedan had low oil pressure10-15 lbs but otherwise runs well. The engine apears to be original and unmolested but who knowes.

The oil pump was removed, disassembled and found to be within the tolerances specified in the manual.The pump was reassembled with new gaskets and reinstalled. The oil filter was full of crap and we addressed this.

Before restarting the car is there a procedure for priming the pump etc?

1stpackard, Tom




1stpackard

Tom

Tom,

I'm most familiar with the 8's vs. 12's but I can offer a few suggestions:

I always run a repaired pump before putting it back on the car. I have a pressure gauge attached to the pump output and have the pump in a can of oil. I run the pump up to 1000 - 1500 rpm (1/2 engine speed)and adjust the pressure relief (if it's on the pump).

If you pressure relief valve isn't on the pump I've check the valve spring, plunger / and or ball for wear.

The low pressure reading could be caused by the pump, fault gauge, improperly adjusted pressure relief valve or worn bearings.

If you can borrow a mechanical gauge check it against the dash gauge to make sure you have an accurate reading.

Before starting you may want to pull the plugs and spin the engine over to make sure you have oil pressure before starting it.

On some modern cars you can make a tool to go down to the pump and spin it with a drill to prime the system before starting. On the pre-war 8's the pump gear is below the camshaft so pulling the distributor to spin the pump shaft will not work.

Regards,

Dave

Dave,
Thank you for the note. I now understand the problem and have been advised on how to prime the pump.

Our 14 series packard has a gear type pump which sits above the oil reservoir / oil pan. The pump is mechanical driven and cannot draw a vacuum when empty. The procedure as described to me but not yet implemented, is to stuff the pump with petroleum jelly or a suitable grease before installing. When ready to start for the first time provide an external source / supply of oil under pressure through the oil filter line or similar external port. The external pump should be pumping prior to starting the engine.

We has not gotten to the point of restarting the engine.

Thank you for the time to write.

Tom

The 320 and 384 pumps, being partially immersed in the crankcase oil, normally self-prime automatically and very easily, just crank the engine w/o ignition until pressure shows on the gauge. I believe the Twelve is the same with the intake screen just above the screen access plate in the oil pan. And yes, packing a pump with a light grease to enable it to easily self-prime is still a pretty standard practice among the knowledgeable engine rebuilders.

There is a special publication now in print about the intracasies of the Twelve oiling system and I'd recommend you get a copy.

Could you please give the title of the paper or an address for information / ordering?
Thanks, Tom

Advertised regularly in The Packard Club newsletter publication. Let us know what you think of it after you've had the opportunity assess it, please.

Attach file:

---

  (118.34 KB)

Thank you for the information and address.
1stpackard, Tom

I guess I see the question as: What do I do if there is no pressure? I had a problem of priming the oil pump on my '47 Custom Clipper with the 356 engine. I know the V-12 is a much different type of engine, but the following may be helpful to you.

I had had the oil pan and screen off for cleaning and it had been several weeks before I was able to restart the engine. Cranking the engine with the spark plugs removed to get oil pressure in the system before starting it revealed that there was no pressure being registered on the gauge. I removed a main bearing oil gallery plug and no oil was being spurt out when the engine was cranked. I posted the problem on this site and got many suggestions. The one I followed was to introduce some oil into the system by removing the oil pressure sending unit. With necessary plumbing I pumped in a quart of oil. This solved the problem, the pump was able to prime and produce flow and pressure. I checked it by again watching if any oil came out of the gallery plug fitting. Cranking the engine made a nice mess on the floor.

This is what I had to do for my engine. I hope you (and others) find it helpful.

(o{I}o)