Oil Pump Priming

[jamesmdavis]

Good Day All:

I am about to replace the rigid lines from the oil pump to the oil filter and from the oil filter to the engine block. I assume that I will lose prime during this process. I never have had to prime the old girl before. Lucky! My unit has no prime plug. What are some of the ways to do this without opening the pump itself? Thanks.

Jim Davis TC 7225 Peachtree City, GA

[Steve Simmons]

I didn't have to prime my pump when I replaced the lines. I would just crank it over without starting and see what happens. If you do have to prime the pump, there are two ways I have done it.

First is to remove the pump cap and pack some Vaseline in the vanes. The other way is to buy a pressurized garden sprayer and fill it with oil. Connect the hose to the lower banjo fitting, where the oil pressure line goes. Pump up pressure and when you see oil come out of the rocker arms, you should be good to go.

[Duncan M]

The garden sprayer method has been around. Can make one hell of a mess. Another well known TC or early TD method I have found easy for priming the oil pump- is to remove the oil supply line, and on the pump end where the supply line went, insert a funnel. A nice selection of funnels is helpful. Put car in top gear and fill the funnel with oil, and then push the car backwards. Depending on how much your funnel holds, you may wish to add more oil before all the oil is sucked in. With a flexible supply line you could also just remove the filter end, and with the loose end raised up, stick the funnel in there. This method is much too simple for most folks around here.

[jamesmdavis]

Hello All:

Thanks for the suggestions. The oil lines are replaced. Really simple installation for the protection it gives.

However, one glitch raised its head. After changing out the lines, I cranked the starter without the ignition being on
and saw the oil pressure begin to rise. I started her up and the oil pressure went to 40 psi which is normally 60psi at this stage. It remained at 40 psi even during a short drive to get her to operating temperature.

Is there an air bubble in the oil system partially blocking the flow? How would one get rid of it? Is the gauge partially blocked or in need of repair? How can I tell? The installation was so minor I can't think of how I could have screwed that up, although I do have a talent along that line. Suggestions would be greatly appreciated.

Jim Davis
TC7225
Lordy its hot in Peachtree City, GA

[Gene Gillam]

Jim,

Doubt that an air bubble would cause a 20lb change in pressure. If I remember correctly when I switched to the flexible lines my pressure read lower too...I eventually went back to the solid oil lines. And although 40lbs seems low it's actually plenty.

Gene

[dirk w dondorp]

could it be, that the diameter difference in solid lines versus flex. lines causes the difference ( ressistance?)
Dirk

[Norman Tuck]

I purchased flexible oil lines from a provider on the list and had the same results, lower oil pressure. I blew through the lines and realized that they had more resistance than the steel lines. The new lines had a smaller internal diameter which restricted the flow. I did not feel comfortable running with reduced oil pressure, and I returned the flex lines to the provider for a full refund.
I then purchased a set of beautiful. braided flexible lines from Doug Pelton at From the Frame Up. After installing these lines I had full oil pressure and am very pleased with the look of the lines, the ease of installation with the rubberized seals that came with the lines, the security of having lines that won't split with vibration, and, of course, having full oil pressure.
I have no relationship with From the Frame Up, other than being a customer.

Norman

[frenchblatter]

If I may drift a bit all this talk about priming pumps reminds me of priming a pump, a sewage pump. When I was in the motor trade my office was at a large garages under an office block in Whitechapel Road, in the East End of London. The sewage and water drained into a large sump under the ground floor of the offices and was pumped up to the mains sewage in the road. No matter how many times I told the mechanics (about 18 of them) not to pour waste oil down the drains they did and it blocked the pick up pipe in the tank. The old boy, Alf who was the maintenance man for the offices would call me to sort it out. We descended into the bowels of the building via a small hatch and rungs set in the walls of the underground chamber. The procedure was to turn the pump off, undo the pick up pipe and clean the gunge stuck to the gauze filter on the bottom, refit the pipe and prime the pump. The priming was done by removing a small butterfly cap from the top and pouring some water in, about 6 plastic cups full. On this particular occasion I had filled with water and was about to put the cap on when Alf, thinking I'd finished (he was always "fussing" around me whilst I did this ) switched the pump on. I got soaked in water based raw sewage. I had to get one of the lads from the garage to go out and buy me new trousers, shirt, underpants and socks, I stank!. The smell didn't come off me for a week. Thanks Alf.

[jamesmdavis]

Hi All: Quite a bit of water has pasted under the bridge since this string started. In that time I have tried other line replacements. All had the same pressure drop. Finally, I procured a set of fittings which allowed me to make test lines which maintained the same (approx 8mm) line ID throughout the fittings and the lines. I had found that replacement lines had ID reductions, particularly at the fittings.

Whereas on cold start the original brass pipes registered 60 psi and the replacement lines registered 40 psi, the test lines registered 65-70 psi. After a hot run the pressure on the original pipes registered 40 psi and the replacement lines registered 30-40 psi, while the test lines registered 50-55 psi. This was all done with a new oil pump which delivers the "goods". Needless to say, I have kept the test lines on. The test lines have braided hoses which are AN sized and fittings which are bsp/AN. They look very similar to the replacement lines currently available. I hope this is useful information to the group.

Jim Davis
TC7225
Houston

[Kenmgtc]

Jim, i have run into almost the exact same issue, a 15 PSI pressure drop across the board using flex lines recently purchased from FTFU.

Where did you get your "test lines" from and can they make another set?

I will PM you as well as this thread is so old i'm not sure it will update you.

Thanks,
Ken

[Steve Simmons]

I experienced a drop in pressure with flexible lines also, but after 20,000 miles then engine is doing fine. Bores and bearings looked good when I inspected them at about 10,000.

[Kenmgtc]

Good to know Steve and I’m trying to justify it to myself. It’s just concerning to look at after being used to much better pressures. I’m going to try fitting the solid ones today which were kind of challenging... need to pick up a tubing bender first.