Priming 55 oil pump

[Jeff Rosansky CLC #28373]

 I am going to pull the pan so the pickup tube will be out of the oil for a while. My schedule is shot so it may be a couple of days before I can get it back together and several more before it is ready to finally run.  I am concerned about the pump losing prime and the resulting start.  I know I can pull  the distributor to prime it but it
is in the back and I am short. Is just spinning the starter with plugs out sufficient? I am going to put a temporary oil pressure gauge in for now. Would it help if I put some oil in thru the oil pressure sending unit port? It seems that should backfill both the pump as well as downstream of the sending units location. It last ran about 3 weeks ago for just a few minutes.
Any thoughts? Should I be concerned about this?
Jeff

[cadman56]

Morning jeff,
I can't tell you if adding oil backwards through the oil pressure sender port will work or not.  It very well may.  I have always pulled the dizzy as you mention.
A couple of things to look for when you get the pan off:
  The pick up is designed to 'float' so it will swivel in the pump.  You may want to check for sludge/carbon build up in the screen and clean it.
  There is a thick felt washer between the pump and a flange on the pickup.  It is always hard.  That felt washer is the seal between the pickup and the pump.  Replace it before you go back together.
Good luck,  Larry

[Jay Friedman]

To be absolutely sure, when you have the oil pump removed take off its bottom plate and stuff as much Vaseline as you can into the pump body.  (You can buy a jar of it in a pharmacy and elsewhere.)  Then re-install the bottom plate.  This will prime the pump and, unlike oil, will not leak out.  When you start the motor you'll have instant oil pressure and the Vaseline will melt away as the oil warms up.  I always do this when rebuilding a motor and / or when I take apart the oil pump. 

[Jeepers Creepers]

If the engine has been running, there wouldn't be any great need to prime.

No different to the car sitting for a couple of weeks in the garage.

If you are really concerned, prior to doing the work, run a litre of STP, Lucas Oil Products or something similar, anti-friction goop through it.

[Bob Kielar]

I recently replaced the rear main seal on my 55 Fleetwood. I buttoned everything up and added fresh oil. I cranked the engine over 5 or 6 times with the coil wire pulled so the caddy would not start. The oil pressure light went out put the coil wire back in place and everything has been running fine.

Keep Cruzin
Bob Kielar

[Jeff Rosansky CLC #28373]

Ok, thanks.
I dont know the internal design but figured if i have the sending unit off it would allow access to the oil system and I mite as well take advantage of it.
My hope here was to not get to the involvement level of pulling the pump. I just want to to drop the pan and clean the sludge out of it. The pan will be off for a few hours because I may take the pan somewhere else to clean it depending on how bad it is. I want to do it this weekend but the starter is off being rebuilt and the guy went on vacation so it won't be ready until next week.
I'll just do it and spin it with the starter and plugs out.
Jeff

[bcroe]

I believe that pump sits submerged in oil, like an Olds.  In that case
there is no worry to prime it, no vaseline needed.  It will just take a
couple extra turns to blow the air out.  With a recently run engine,
I'd just spin it with ignition disconnected till the light goes out,
and you are ready. 

The pumps mounted outboard are a much bigger problem; the
vaseline usually works on them.  I don't care to take them all apart,
so I wheel a new engine up to my car and connect a high pressure
hose between the 2 oil pressure ports.  I let the car idle for half a
minute or till a quart of oil moves over to the new engine.  Then I
shut the car off, and spin the new engine with the starter (no plugs)
until a quart of oil moves back.  Job finished.  Bruce Roe

[The Tassie Devil(le)]

Back-filling the oiling system through the oil pressure port most likely will not work, as these days, the oil filters have a anti-drain-back valve inside them, and therefore all you would be filling is the filter, and whatever else is on the path backwards, and forwards, until the excess from the "leaking areas" drain into the sump.

Bruce.

[bcroe]

Back-filling the oiling system through the oil pressure port most likely will not work, as these days, the oil filters have a anti-drain-back valve inside them, and therefore all you would be filling is the filter, and whatever else is on the path backwards, and forwards, until the excess from the "leaking areas" drain into the sump.    Bruce. >   

Well after all, filling whatever is backwards and forwards is the idea.  I have
heard of bypass valves for a blocked filter, is there in addition an anti-drain-
back valve too?  If a filter can be completely effective in blocking oil to the
pump, I would need to add to my procedure to using a filter not having an
anti-drain-back valve.  I must have used the type, as it has primed a pump
on several engines to date.  Bruce Roe

[savemy67]

Hello Jeff,

I to am not gifted with a basketball player's height.  I remember what a pain in the back it was to get at the distributor in my small block Chevy's back in the day.

If you remove the spark plugs, I think you should also ground the high tension lead from the coil so there is no chance of a spark occurring at the end of a plug wire.  Some fuel may be drawn through the carburetor and expelled through a spark plug hole into your engine bay.

As others have mentioned, you can use your starter to crank the engine, but be sure your battery is in top notch shape.  If you have a mechanical oil pressure gauge, you may want to plumb it in where the oil pressure sending unit was installed.

I know the '60s shop manuals have an oil circuit diagram.  If you have the manual for your '55, see if it also has an oil circuit diagram.  The diagrams and text can be helpful in understanding how the engine oiling system works.  Good luck.

Respectfully submitted,
Christopher Winter

[Jeff Rosansky CLC #28373]

It has the bypass type filter on the top of the engine. That's why I was wondering if it would drain down backwards.
Jeff

[The Tassie Devil(le)]

Oops, I forgot that the spin-on Filters with the anti-drain-back feature couldn't be used until 1960.

Prior to that, the canister type were used, and sat up high.

Definitely a brain fade.

Bruce.

[Roger Zimmermann]

Why the hassle? When I replaced the rear seal on my '56 and '57, the engine was of course still installed into the car. I filled the oil pan with the needed quantity of oil and started the engine. The oil pressure came relatively quick.

[bcroe]

Why the hassle? When I replaced the rear seal on my '56 and '57, the engine was of course still installed into the car. I filled the oil pan with the needed quantity of oil and started the engine. The oil pressure came relatively quick. 

The hassle is about priming a new engine with outboard pump, neither of which
applies to your cases.  Bruce Roe