Verify oil pump working

M

Magoo2

Member
What is the easiest way to verify your oil pump is working properly? I don’t have an oil pressure gauge installed.
 
Either momentarily remove the plug where a pressure gauge line would attach or loosen the oil return tube and run the engine. Could get messy.
WHY??
Paul in CT
 
I’m just second guessing myself. I rebuilt the oil pump and reinstalled it. And was thinking I really don’t know if the pump is working.
 
What about temperature tracking? Wouldn't the oil return tube heat up faster if it's flowing oil? Otherwise, a dry tube out in the air would stay closer to ambient.

Get a laser thermometer (under $35 most places) and hopefully you have a friend with a Model A for control. Start the control from cold and plot the temp vs time of the oil tube, along with the adjacent block temps. Then compare that to yours. As the oil warms, the pipe should warm, and the trend should be similar.

Not very precise as ambient temp, airflow, oil flow and differences in how the control engine disperses heat vs yours all enter into it, but if you see a strong correlation, and verify it by comparing the tube to the oil pan temps, it might tell you what you want to know.
 
Watch the oil flow:
 

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The pump is submerged in oil in the pan, if it is turning, it is pumping. If it is not turning, the bearings will soon be alarmingly noisy.
 
1931 flamingo said:
Either momentarily remove the plug where a pressure gauge line would attach or loosen the oil return tube and run the engine. Could get messy.
WHY??
Paul in CT
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I agree with Paul. This is the easiest and in my view best way to assure the pump is working.

Plus remember that the Model A oil pump moves a lot of oil. You could have a mess.

Good luck.
 
You don’t have to run the engine. Take the plug out and have someone hit the starter for a moment with the key off. The oil should flow out a little. Not much mess at all. I’m sure you did a good job.
 
If you rebuilt it and don't have any parts left over sitting on the work bench I'm thinking it's working.
 
Its a gear pump, almost bulletproof. If it is turning it is working. All it does is deliver oil to the valve gallery. Everything is gravity fed from there.
 
Mister Moose said:
Or spend under $10 for a gauge plus a few adapters at the hardware store. Mount it on the engine temporarily to do the test, replace with the plug. Here's a 0-30 psi gauge for $6.90:

https://www.supplyhouse.com/Winters...M-Dual-Scale-Economy-Pressure-Gauge-0-30-PSI?
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Make it a permanent install, not that hard to do. You'll see 2 to 10 psi pressure when you start the engine depending on temperature. After warm up pressure will drop to near zero when idling and may go up a little at higher rpm. Otherwise give your car an oil bath as others have suggested by removing the the block plug.
 
I did what Katy did... old tube, about $3 worth of parts to give a quick visual indication. I had rebuilt a pump with a kit from Brattons on my new AER engine and did the messy way, and it seemed way too long to get oil flow. So I bought a new pump from Brattons and installed my visual tube, and I had oil in 20 seconds. Much greater oil flow from a new pump vs my rebuild. And it was a pretty easy rebuild. Like some of the other posters, I felt that a gear pump submerged in oil is foolproof; now I’ll never use anything but a quality new pump.
 
Bruce_MO said:
I did what Katy did..
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Actually, all I did was install the vinyl tube. When I bought this A it had a piece of rubber hose on it. I suspect that some PO had a "short" version of the oil return tube and needed a "long" version for this engine, so they just cut it and used the rubber hose to extend it. I didn't like the idea of the rubber hose being exposed to hot oil so that's why I replaced it w/vinyl. Being able to see the oil flow is just a side benefit.
 
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