Oil pump failure?

thethee

Well-Known Member
Joined
Feb 13, 2021
Messages
808
Reaction score
796
Location
Netherlands
Hi all, could really use some help here.

This weekend I finished the install of the timing chain in my 440. Since it was also leaking oil badly took the opportunity to also replace main seals so it sat for a while with the pan off. Was a little nervous since I never did this before, but she started right up. Problem is the oil pressure warning light stays on.

The oil pressure sending unit is new. The new oil is 10w40 and it reads just under the full mark on the dipstick. The oil filter is a new Wix 51068 and I pre filled it before installation. When I removed the filter and cranked the engine on the starter no oil is coming out of the pump outlet. It had good oil pressure before I took it apart.

I plan on pulling the oil pump, or am I missing something here?

-Theo
 

detmatt

Old Man with a Hat
FCBO Gold Member
Joined
Nov 14, 2010
Messages
27,078
Reaction score
24,538
Put the old sending unit back on and see what happens.
 

MEV

Active Member
Joined
Mar 28, 2015
Messages
325
Reaction score
426
Location
WA
temporarily install a mechanical gauge, just run a line from the same port as the sending unit was in, you can extend the line and sit in the car and check it.
 

thethee

Well-Known Member
Joined
Feb 13, 2021
Messages
808
Reaction score
796
Location
Netherlands

bigmoparjeff

Senior Member
Joined
Aug 9, 2017
Messages
2,478
Reaction score
3,282
Location
Dublin, PA
I agree with traintech55.

I've had it happen to me in the past. It likely would pick up prime eventually, but you could damage the engine by then. Your best bet is the priming tool. Oil pumps aren't that expensive, and it might not be a bad idea to just replace yours, but you would still want to get the tool and prime it first.

The second choice, not as good option, would be to pull off your pump and inspect it. If it looks ok, pack the inside with petroleum jelly, reinstall and start it up.

If you decide to get a new pump, buy a Melling. There have been issues with other brands lately.

I've seen some odd oil pump problems. My '69 Imperial would be fine until it reached a certain temperature, then the pressure would instantly drop to zero. If I let the car cool down, then restart it, the pressure would be fine again until it warmed up. A new pump solved the problem. The previous owner of my '67 Imperial told me that at one time he changed the oil on the car and it refused to re-prime, so he had to have the oil pump replaced. The oil pressure had been fine up to that point.

Jeff
 

thethee

Well-Known Member
Joined
Feb 13, 2021
Messages
808
Reaction score
796
Location
Netherlands
Okay, I will look into priming the pump first.
About that tool, could I just make one myself? Shipping costs from the US are generally pretty steep so rather avoid them. Also, how difficult would it be to remove the drive gear with the engine in the car?
 

thethee

Well-Known Member
Joined
Feb 13, 2021
Messages
808
Reaction score
796
Location
Netherlands
I did fill the filter but maybe just not enough.

What is the allen key size for the prime tool, 5/16?
 

413

Senior Member
Joined
Jan 28, 2019
Messages
1,355
Reaction score
1,467
Location
NW USA
Prime the pump is the only way to go. You don’t need to pack it with anything first.

yes 5/16 hex you can make one from a round rod. I made them before with a grinder, and grind 3 flats on top so it won’t spin in the drill.
Turn it CC and when you get pressure it will put a good load on the drill, and the oil filter can will not flex anymore if you squeeze it with your hand.
 

stubs300

Senior Member
Joined
Oct 30, 2011
Messages
3,421
Reaction score
2,999
Location
Free America
I had a no pressure problem after doing a oil change, come to find out that I sheared the dist. shaft where it goes into the oil pump. A new one fixed the problem. Good Luck
 

Slap Stick

Active Member
Joined
Dec 3, 2020
Messages
253
Reaction score
164
Location
St. Charles county, MO
Get a 5/16 socket bit with an extension and using an adaptor to the 3/8 socket attachment chuck it in your drill motor.
You probably already have everything in your tool box.

You said you PRE filled the filter. You still need to fill it.:poke:
 

413

Senior Member
Joined
Jan 28, 2019
Messages
1,355
Reaction score
1,467
Location
NW USA
Get a 5/16 socket bit with an extension and using an adaptor to the 3/8 socket attachment chuck it in your drill motor.
You probably already have everything in your tool box.

You said you PRE filled the filter. You still need to fill it.:poke:
How is this going to get past the bushing in the block? It will not fit.
 

HWYCRZR

Senior Member
FCBO Gold Member
Joined
May 13, 2015
Messages
4,458
Reaction score
5,982
Location
Fargo, ND
Hardware store,or home builder store, (Not familiar with hardware stores in the Netherlands). drywall or plaster mixer with hex shaft is about the right size at least in NA. Cut about 10-12” off of it, use what you cut off to prime.
 

73Coupe

Senior Member
Joined
Nov 12, 2014
Messages
2,209
Reaction score
2,394
Location
San Luis Obispo, CA
You could have gotten foreign matter stuck in the relief valve, with the pan off and performing repairs, there might have been old plastic timing gear bits floating around. It just takes a speck the size of a large sand grain to hold the relief open, therefore killing the pressure. This happened to me.
Did you inspect and clean the pickup screen?
 
Last edited:
Top