Testing cub oil pressure gauge?

[Dale Finch]

I seem to have a collection of oil pressure vauges from cubs and super a. Is there a way to bench test them? Maybe using air from compressor?

[Don McCombs]

Secure the gauge in a vise. Use an old (or new) tubeless tire valve stem to place firmly over the "inlet" port on the gauge. Set your compressor regulator to 35 pounds. Apply the air chuck to the valve stem and observe the results.

[Dale Finch]

Thanks. Wasn't sure if air would cause any problems.

[Don McCombs]

Air and oil are both fluids. Air is compressable and oil is not. But, at that scale, I don't think the difference would be noticeable.

[Dale Finch]

Great! Going out to crank up the compressor!

[John *.?-!.* cub owner]

Don't just test it at 35 pounds. I had one that at 35 pounds was correct, but at 15 to 20 would read 0. Even on a good engine, oil pressure when hot and at idle dropping to 10 or 15 pounds is not unusual, and is ok.

[Don McCombs]

I agree with John. Just don't apply 150 psi to it.

[staninlowerAL]

You can also use a 1/8 NPT fitting. Screw the gauge in one side and a quick connect fitting on the other side. You can take it a step further by installing a small valve in the air line next to the NPT fitting so you can control the air and not shock the gauge. You can go one more step and make the NPT fitting a tee and screw a known good gauge in for a comparison check.

[Dale Finch]

The good news...I lucked out...I had an air gun with a detachable nozzle tip which had the same pipe threads as the oil p-gauge.

I screwed the gauge onto the gun, which had a trigger, and starting at 10psi, slowly increased the pressure in incriments. That's the good news.

The bad news is that all of them are questionable, with one being way off the readings. That is assuming my Makita air compressor gauge is in anyway accurate! I ended up using one that read a tad lower than the compressor gauge, but seemed to respond linearly on the scale. It'll have to do for now.

[Jim Becker]

Compressor gauges aren't known for particularly good accuracy. Your "questionable" gauges more be more accurate. It would be helpful if you could cross check with a decent tire gauge.

[John *.?-!.* cub owner]

Compressor gauges aren't known for particularly good accuracy. Your "questionable" gauges more be more accurate. It would be helpful if you could cross check with a decent tire gauge.

it would take a little creativity to connect them, but most of the inexpensive digital gauges are very accurate.