How can I test a loader for cylinder vs control valve leakage??

[oldnslo]

Yes, I can support the FEL with a jack, then remove it.

What do mean by ç*¥nplug quick disconnect in the cap end of the cylinders?

I meant that you need to determine which hose connects to the cap or (lift end) of the cylinder and then unhook or unplug that quick disconnect. This will isolate the cap end of the cylinder from the valve. By leaving the rod end hose connected you have a path for the oil to return to tank IF the piston seals are leaking.

 

[WranglerX]

A way to test a cylinder....

Bypass testing a hydraulic cylinder - YouTube

Dale

 

[4lane]

I meant that you need to determine which hose connects to the cap or (lift end) of the cylinder and then unhook or unplug that quick disconnect. This will isolate the cap end of the cylinder from the valve. By leaving the rod end hose connected you have a path for the oil to return to tank IF the piston seals are leaking.

I see. I believe you're describing DL Meisen's test: Bypass testing a hydraulic cylinder - YouTube, by unplugging the disconnect circled here in blue, correct?

 

[Oldoak]

A way to test a cylinder....

Bypass testing a hydraulic cylinder - YouTube

Dale

Excellent demonstration by someone who really knows what they are talking about.........and teaching! :thumbsup:

 

[oldnslo]

I see. I believe you're describing DL Meisen's test: Bypass testing a hydraulic cylinder - YouTube, by unplugging the disconnect circled here in blue, correct?

View attachment 558172

4 lane,
What I suggested is a very similar concept except you will be using the weight of the loader to create the pressure & not using the tractor hydraulics.

The line circled in blue in the line that you need to trace back to one of the quick disconnects located by the loader mounting frame. Unplugging the quick disconnect should be easier that removing and then plugging the fittings at the cylinder.

 

[4lane]

4 lane,
What I suggested is a very similar concept except you will be using the weight of the loader to create the pressure & not using the tractor hydraulics.

The line circled in blue in the line that you need to trace back to one of the quick disconnects located by the loader mounting frame. Unplugging the quick disconnect should be easier that removing and then plugging the fittings at the cylinder.

Understood, thank you.

 

[4570Man]

You’re making this too hard. It’s impossible to push the rod into the cylinder without leaking oil past the valve or leaking externally.

 

[oldnslo]

Youæ±*e making this too hard. Itç—´ impossible to push the rod into the cylinder without leaking oil past the valve or leaking externally.

By doing this test You are using the loader and valve to determine what if anything is leaking. If the loader drifts down the seals on the piston and the valve are leaking. By fixing the seals on the cylinder you have eliminated one leak path. The unknown is still the valve leakage on the blind or cap end of the cylinder. Trying to eliminate one leak point using the loader which is something I know 4lane has.

Sorry if this seems to complicated.

 

[4570Man]

It’s impossible for the cylinder to retract without the valve leaking or external leakage. There’s no need to suffer through trying to get the quick connects re connected under pressure. It doesn’t prove anything that’s not already proven. It’s still possible for the cylinder to extend with the quick connects undone. If the cylinder seals are bad it’s going to pass oil past the seals into the other end. Since the cylinder volume is getting larger no oil needs to move out of the cylinder. Again it’s impossible for the rod to retract without pushing oil out of the cylinder rather it goes out the end or out the valve. Since it’s apparently not leaking out the end that means the valve is leaking. I’d bet money that the loader stays up indefinitely with the quick connects unplugged assuming no oil leaks out.

 

[CalG]

I'm with 4570Man

Simple "volume issue" You can NOT put a liter of oil plus 1/2 liter volume of steel shafting into a 1 liter volume cylinder.

The oil must go somewhere!