John Deere 26G losing hydraulic oil with no visible leaks

[BREE26]

Hi all,

Having issues with my 2018 John Deere 26g. Bought at auction and fluid level was in good shape at the time. Noticed level down a bit after going through some basic maintenance and adding a thumb in the barn so topped off before initially using the machine. Used for a few hours the first day all seemed well. The second day started to notice a bit of a winding noise coming from the pump. Did not use again for about a week noticed bucket cylinder gradually not holding and showing very low oil level. Refilled and noticed the noise getting louder. Do not want to operate any further until I address the pump noise. Checked the engine oil not seeing anything milky looking or air bubbles and not really seeing an increase in fluid level in engine oil. Is it worth sending the oil to the lab to be tested? Am I moving in the right direction as far as troubleshooting? any advice or tips greatly appreciated.

Thanks again

 

[mg2361]

Are either of the planetary gearboxes on the drive motors filling up with oil?

For the noise, start by making sure all the hose clamps for the pump's inlet are secure.

Also, check the suction screen that is in the tank. That would be accessed from the same cover you fill the reservoir from.

You can get a free copy of the operators manual here

 

[BREE26]

So I did pull the level plug briefly yesterday before I went to work and noticed it had some pressure on the right side gearbox then ran out of time before i had to leave. Felt like that was not normal. Today pulled samples and right side has about 5-8 oz of excess oil out of level plug that I am assuming is contaminated. Not sure if I can send these out to the lab and they determine if it is contaminated with specifically hydraulic oil or just contaminated based on viscosity. The left side gear box had a lit bit of excess but not like the right side. This seems like I'm headed more in the right direction and I really appreciate your advice. If it is ending up in the gear box can you change the seals on these or do you have to order a remanufactured final drive assembly? Is it possible the pump noise is it overworking to try to push the overfilled final drive?


Thanks again

 

[mg2361]

Did the amount of excess fluid in the final match what you added to the hydraulics? 5-8 ounces is not much. Sounds like you had added way more oil than that to the reservoir. Does the area behind the sprockets show any signs of oil leakage? Sometimes leak there get lost in the dirt.

Did you check to see if any oil was leaking from the center joint under the center of the machine? Sometimes leaks occur externally, but are not noticed due to the oil dripping into the dirt while moving around. Are you sure there is not any oil laying in the bowels of the machine and not making to the ground because of accumulated dirt?

An oil sample of the finals will show a viscosity error if the hydraulic oil is getting into the finals.

Is it possible the pump noise is it overworking to try to push the overfilled final drive?

No.

However, I would be concerned about the noise. Cavitation will wreak havoc on the system. I would be worried about this before the oil loss, unless the oil loss is due to a loose clamp on a suction line.

 

[BREE26]

You’re correct I did add more than that to the reservoir for sure. I’ll have to do a more thorough inspection of the center joint I didn’t really see anything initially. I agree the cavitation is a big concern. When I added fluid to the reservoir I wasn’t able to bleed at the pump from where previous owner stripped the Allen head bleed plug. The manual suggests bleeding every time but read a few places not a big deal unless doing a complete flush. Any thoughts on it being air from opening the reservoir?

 

[mg2361]

Any thoughts on it being air from opening the reservoir?

Opening the reservoir does not introduce air into the hydraulic system. Cavitation can be air from a hose clamp leak on the suction side or a vacuum from a restricted suction screen, among other things. Make sure you check these things.

Do take note that some of the Deere mini's have had hydraulic whining complaints (50G in particular) to only find out the noise is normal. Annoying, but normal. I had a 50G that Deere had me install a second set of noise insulating panels over top of the originals to make a customer happy.

 

[BREE26]

I did manage to get all my samples together and just looking at them compared to one another right side drive looks like water in a mason jar as far as viscosity compared to left side and motor oil. Again i really appreciate your time and advice. Just one more maybe dumb question. When I added the thumb it was pre packed with hydraulic fluid it discharged and bled some fluid out when adding connections would this be a point of entry for air or am I overthinking this? Thanks again

 

[mg2361]

Not likely your issue. You would have had some air, but it should have worked itself out after a couple of cycles.