Is the leak in the room with us now? Mystery hy-tran leak.

[MinnesotaEric]

My HST tractor is consuming 3-4 quarts of hy-tran every few hours of doing loader work. The hy-tran is shared for the steering, hydraulics, and HST. The skid plate is off so nothing is pooling on top of it.

First, the dye I used last fall to find two hydraulic leaks off of the pump has been diluted to the point where I cannot see anything with a black light. So I may need to order more dye and do it all over again.

Second, there are no obvious leaks, puddles, or drips on the underside of the tractor.

Third, the right boom cylinder does leak but it appears to be a weep that I cannot account for the amount of fluid I'm losing.

Up on blocks, I focused on the weeping boom cylinder by cycling it up and down a bunch of times, and forcing the machine to relief on the top and bottom of the stroke. I got what amounts to a whole drip, and that it.

I am making slash piles so the tractor loader is bouncing with the tractor as I carry slash over uneven ground, but back at my tinkerage I don't have a good way to simulate carrying a load other than to grab a log and drive up and down my driveway and see if the cylinder suddenly leaks a ton, but while in use, I have not noticed any leak down of the loader even when sitting for a bit, let alone when using it.

Even so, the machine is consistently going through hy-tran. Anybody got any ideas or weird experiences that may shed some light on my mystery leak?

 

[zzvyb6]

are you burning it ? Park the machine and leave it running at a fast idle for an hour or so after topping off the oil level. No steering, no loader work, no 3 point activity means you are burning it, unless the tires are really stating to balloon out....

 

[MinnesotaEric]

are you burning it ? Park the machine and leave it running at a fast idle for an hour or so after topping off the oil level. No steering, no loader work, no 3 point activity means you are burning it, unless the tires are really stating to balloon out....

Okay, you have me: how could the machine be burning hy-tran?

 

[zzvyb6]

Okay, you have me: how could the machine be burning hy-tran?

For 1, check your pump to see if it could get near air-in or crankcase suction cracks or seals. So rpm dependent only.

For 2, There may be leak dripping on the exhaust manifold so it's evaporating almost instantaneously. Can you smell it?

For 3, your fuel pump may be getting of oil via some bad gasket or crack, or plugged check-valve. If so, the loss rate would be power output dependent, meaning nothing at idle, but heavy at full power output.

For 4, Leak or exchange in the oil cooler, so evaporating when running hot.

 

[dodge man]

How is the pump setup? Mine for example is near the back of the tractor driven by a driveshaft so I don’t think it possible I could burn any.

 

[rScotty]

Hydraulic fluid can get into the engine crankcase when an engine-driven hydraulic pump has a bad internal seal on the pump drive. It's not uncommon, and not difficult to fix.
The usual symptom is that the crankcase oil level rises. It doesn't sound like you have noticed that as a problem, but it is worth checking.

 

[MinnesotaEric]

After my opening post, I pressure-washed my tractor to make sure everything was oil-free and dry, and then the weather turned cold and windy and if it wasn't cold and windy, it was cold, raining, and windy. So roll forward two weeks...

Yesterday, I idled the tractor for an hour hoping to discover a leak that explains my mystery leak. I exercised the third function a bunch of times to relief, and inspected the bits for the third function that I made for my tractor years ago (it still looks and works better than Kioti's own third function kit). I also exercised the three-point up and down.

The result? nothing. No leaks anywhere.

Today I walked out thinking I would put the entire tractor up on jack stands and allow the tractor to "drive" thinking that the tractor moving had something to do with the missing Hy-tran fluid and noticed two puddles.

Long story short: the left three-point cylinder is leaking and the fluid is dripping down the left lower arm.

So now I've got to order in a rebuild kit and puzzle out how to R&R the lefthand three-point hydraulic ram. In the meantime, I can do my hy-tran service.