Hydraulic Issues Continued

[oldnslo]

Do hear any noise at all that is unusual or different when trying to operate the FEL or 3 point? Possible sound like water rushing out of a garden hose..


Depending on how they are made it is possible pump is losing prime after sitting for a period of time but not real common. The way to Check for that is to crack a fitting open on the outlet or pressure line of the pump, then turn engine over to see if any oil comes out. If you mechanical fuel shut off easy to keep engine from starting.

 

[Beaverplt]

I haven't heard any unusual noises. I can easily open the fitting on the outflow side of the pump. i'll try that tomorrow.

 

[rScotty]

So, I'm back with the same old problem. I needed to move several yards of mulch but the hydraulics on "Bubba" (Swmbo's name for it) would do nothing. I've attempted several times over the past four days and still nothing. I have for the past few years thought this is a problem with the FEL. It dawned on me today that it's not just the loader. My three point hitch does not raise either. The filter is clean. The transhydraulic fluid is only a year old. I'm totally lost at this point. Any ideas? Thanks

I'd get a 5000 psi pressure gauge, a hydraulic Tee, and the fittings to put that gauge in the pressure line on the output of the hydraulic pump. Cost about $50 on Amazon. See if you have any pressure.

Please DO NOT simply loosen connectors to see if they leak without incredible precaustions. Make sure tractor cannot start. Use some serious shielding. Hydraulic spray from a loose connection can cut like a knife and happens instantly. Do a google search and read up on that danger before doing any hydraulic leak tests yourself. It's Very Scary stuff. You cannot be too careful with hydraulic pressure. More dangerous than a cobra. An invisible thin spray can penetrate the skin and cost a limb or worse.
Please do not put Swmbo in danger.

Usually when the system completely stops working without weird noises it is a suction line leak. Some aged connection is letting air into the line somewhere between the output of the cleanable filter in the transmission and the input to the hydraulic pump.

If so, you can often find it because the area of the leak will be wet with oil after sitting overnight.

rScotty

 

[oldnslo]

Rscotty
You are 100% correct on high pressure leaks being dangerous. In this case there is no pressure since nothing is moving which points towards a flow loss. Intention was to see if pump lost prime either from air leak in inlet or from sitting over time and oil drained back to tank.

This is an open center system so will be low pressure until a function is activated.

 

[LouNY]

We often tend to fill hydraulics above the full line living and working on steep hills over full works better then almost full. It does sound like a suction leak to the pump as well as the possibility of pump wear contributing to a weaker suction so less priming capability.

 

[Beaverplt]

Today I loosened the bolts on the outflow side of the pump. Turned off the fuel and cranked the starter. With it being on open center system I wasn't worried about a high pressure spray, but I did make sure all the levers were in a neutral position. There was a brief pause, then a gush of fluid. Perhaps the pause was an air pocket? I tightened it up and started the tractor. The hydraulics worked fine.
I'm looking for possible air leaks. I recently repaired one of the lift cylinders on the FEL and the other 3 are good. One area I should look at closer is the PTO. I don't use it, so I tend to forget about it. Thanks guys for the assistance. I'll let you know if I find anything.

 

[rScotty]

Today I loosened the bolts on the outflow side of the pump. Turned off the fuel and cranked the starter. With it being on open center system I wasn't worried about a high pressure spray, but I did make sure all the levers were in a neutral position. There was a brief pause, then a gush of fluid. Perhaps the pause was an air pocket? I tightened it up and started the tractor. The hydraulics worked fine.
I'm looking for possible air leaks. I recently repaired one of the lift cylinders on the FEL and the other 3 are good. One area I should look at closer is the PTO. I don't use it, so I tend to forget about it. Thanks guys for the assistance. I'll let you know if I find anything.

Real interesting - especially about the brief pause followed by flow. BTW, thanks both for the follow-up and also for being cognizant of my high pressure spray concerns. I experienced a spray once.

Not sure how the suction line is built on your tractor. On mine there is a short steel tubing at the filter and the same at the pump with a rubber hose section clamped to connect them. Lots are that way, and the rubber gets old and starts leaking from invisible cracks on the inside surface of the rubber where it slides over the tubing.

The diagnostic is seeing oil wetness at the end of the hose. Not enough to drip, just enough to wet the hose and tubing. Worth checking.

rScotty

 

[oldnslo]

Today I loosened the bolts on the outflow side of the pump. Turned off the fuel and cranked the starter. With it being on open center system I wasn't worried about a high pressure spray, but I did make sure all the levers were in a neutral position. There was a brief pause, then a gush of fluid. Perhaps the pause was an air pocket? I tightened it up and started the tractor. The hydraulics worked fine.
I'm looking for possible air leaks. I recently repaired one of the lift cylinders on the FEL and the other 3 are good. One area I should look at closer is the PTO. I don't use it, so I tend to forget about it. Thanks guys for the assistance. I'll let you know if I find anything.

That test does point towards your pump losing prime now the challenging part is to determine why and or where this is happening. If pump is dead quiet during operation any inlet air leak is small or you would hear the pump cavitate which is similar sound to a rock crusher.

If pump is getting worn I would expect some performance loss like wouldn’t lift a bucket of dirt.

Now that it is working a quick simple test for worn pump is dead head a function for 10 - 15 seconds and then immediately feel the pump housing to see if significantly warmer than the inlet and outlet lines. A worn slipping pump will get warm pretty quick. If you have thermal heat gun they work also and won’t get burnt fingers..

 

[wdchyd]

The proper flow/load meter temporarily installed inline just after pump (or before the first valve) would tell you instantly if it’s the pump or something else downstream.

 

[wdchyd]

The delayed gush would definetly indicate a suction leak and oil draining back to reservoir when its not used