Will I damage a hose if I clamp it shut to do a cylinder leak down test?

[lhfarm]

I know the normal method is extend the cylinder, then remove the hose to test for leak-down. I don't have a disconnect or any method to remove the hose while maintaining pressure. Will I damage the hose if I us vice grips or clamps to act as the disconnect?

Thanks,

 

[k0ua]

I know the normal method is extend the cylinder, then remove the hose to test for leak-down. I don't have a disconnect or any method to remove the hose while maintaining pressure. Will I damage the hose if I us vice grips or clamps to act as the disconnect?

Thanks,

I think so yes.

 

[RickB]

Yes you will damage the hose. You will also have no idea whether it is completely pinched off. I do leakdown tests with a non-contact infrared thermometer without any other tools. 100% effective when done properly.

 

[aircommuter]

Do you want to know if the cylinder is leaking internally?

 

[Tx Jim]

Rick
Would you please explain your procedure for using infrared thermometer for this test?
Thanks,Jim

 

[lhfarm]

Do you want to know if the cylinder is leaking internally?

Yes. Trying to determine if the cylinder or control valve is leaking. Lift drops even when the jeep is running, so assuming it is the cylinder.

I too would like to hear about Rick's test.

 

[RickB]

Do you want to know if the cylinder is leaking internally?

Best to start with a cold system. Start power unit, extend or retract cylinder fully, whichever is most convenient.

Hold system over relief for brief periods, on/off so as not to overheat oil supply or damage pump. Two or three minutes of cycles is usually sufficient

Oil rushing over a failed piston seal will warm the cylinder barrel in the area of piston contact.

As little as 5 to 10 degrees temp differential at the piston proves a failed piston seal.

Some piston seal failures leak only one way, it may be necessary to test in both directions.

Great for diagnosing loader cylinder failures where it is not cost effective to rebuild or even disassemble two cylinders when one has failed.

No oil spilled, no wrenches, no dirty hands.

Absolutely never had a false positive result with a $50 IR gun. Will also pinpoint valve problems by eliminating a cylinder as a culprit.

 

[RickB]

Yes. Trying to determine if the cylinder or control valve is leaking. Lift drops even when the jeep is running, so assuming it is the cylinder.

I too would like to hear about Rick's test.

Single acting or double acting cylinder?

 

[lhfarm]

Single acting or double acting cylinder?

Single action - but this is an antique cylinder on my 1949 Jeep. Instead of a drain or breather, it has a hose at the bottom, which empties into the top of the reservoir. Long story, but it lifts great, but starts to drop immediately. Thanks for this great tip. I'll do some testing and get back to you.

 

[aczlan]

Single action - but this is an antique cylinder on my 1949 Jeep. Instead of a drain or breather, it has a hose at the bottom, which empties into the top of the reservoir. Long story, but it lifts great, but starts to drop immediately. Thanks for this great tip. I'll do some testing and get back to you.

Why not just disconnect the bottom hose and see if any fluid comes out of it?

Aaron Z