M6800 Hydraulics not working in cold 20F. Tractor 20 years old. 1350 hours.

[Gus1957]

Hello,

I've read other posts on this topic. My tractor sits a lot and outside all the time after 2 days of 10F nights, day was 20F and I started tractor.
Moved about 100' putting loader into a snow bank to move it and all hydraulics went dead: steering, F/R shifter, 3 pt and loader.

My neighbor brought down his Landini and pushed me back to near barn.

Today its 44F: Tractor started and hydraulics are all working.

There could be a tinge of milky on rear dip stick but hard to tell being a short surface and light oil.

In the past 2 years I've blow 2 different hydraulic hoses and when I replaced them did a complete drain and changed both filters.

I'm going to do another complete drain including filters and new oil.

Question:

If I can get the small set screw type plug out of the steel line under the hydraulic pump and I use air to blow line back to transmission case will that work/ or do I need to disconnect both steel line flanges from under the pump.

Thank you for the help!

 

[North Idaho Wolfman]

You don't need to blow anything out it will drain when you pull the filters.

When you lost hydraulics to the loader did you also loose steering and three point control?

What fluid are you using?

Check these connections for wet spots, if it's sucking air then it will cavitate the pump.

 

[Gus1957]

You don't need to blow anything out it will drain when you pull the filters.

When you lost hydraulics to the loader did you also loose steering and three point control?

What fluid are you using?

Check these connections for wet spots, if it's sucking air then it will cavitate the pump.

View attachment 144449

Thank you for the input.

Always Kubota Oil SUDT.

I'm thinking I should get Part 050 Orings - break the line and check it out.

Lost all hydraulic functions. Steering 1st, loader, F/R Shuttle and 3 pt.

 

[North Idaho Wolfman]

Thank you for the input.

Always Kubota Oil SUDT.

I'm thinking I should get Part 050 Orings - break the line and check it out.

Lost all hydraulic functions. Steering 1st, loader, F/R Shuttle and 3 pt.

All signs are pointing to suction issue and cavitation the pumps, it doesn't take much air to do it.

Check the motor oil and make sure it's not overfull, a bad main shaft seal on the pump will cause that.

 

[Gus1957]

All signs are pointing to suction issue and cavitation the pumps, it doesn't take much air to do it.

Check the motor oil and make sure it's not overfull, a bad main shaft seal on the pump will cause that.

Engine oil is good.
It is 35F today and moved a couple heavy loads of firewood with no problems.
Waiting for 5F to give it another test Saturday.

The O-rings in-between the steel line sections >. I can't see that joint because of the loader frame there.

How are those lines coupled? Nut and flared fitting?

Thank you for the help !

 

[North Idaho Wolfman]

Engine oil is good.
It is 35F today and moved a couple heavy loads of firewood with no problems.
Waiting for 5F to give it another test Saturday.

The O-rings in-between the steel line sections >. I can't see that joint because of the loader frame there.

How are those lines coupled? Nut and flared fitting?

Thank you for the help !

The fitting is just a slip fit.

 

[Gus1957]

Follow Up: So far it appears to be just junk in the hydraulic fluid as all hydraulic systems working after changing fluid and filters. Color of oil was not clear. Worked and functioned properly right after the change moving buckets of firewood. Then it sat for 3 days in the cold back down to 10F. Started yesterday at 30F and plowed driveway with no issue.. This is the 3rd year in a row of completely changing oil and filters in a bout 150 hours. Surprised I could get that much junk from 1 cylinder off the disc.

 

[North Idaho Wolfman]

Follow Up: So far it appears to be just junk in the hydraulic fluid as all hydraulic systems working after changing fluid and filters. Color of oil was not clear. Worked and functioned properly right after the change moving buckets of firewood. Then it sat for 3 days in the cold back down to 10F. Started yesterday at 30F and plowed driveway with no issue.. This is the 3rd year in a row of completely changing oil and filters in a bout 150 hours. Surprised I could get that much junk from 1 cylinder off the disc.

I bet your getting more from condensation than anything else.
Check the vents on the hydraulic system.
Your model has 2 vents and both are equally important.

 

[amschind]

I had everything go dead and found that it was nasty hydraulic fluid and clogged filters. Drained fluid, replaced filters and all worked as it should. FYI, the fluid on my dipstick looked like it came new from the bottle, but the stuff at the bottom was a milkshake. In terms of assessing the fluid, the information you need is clustered around the drain plug and filters, but the dipstick won't tell you much unless it is REALLY bad.

 

[North Idaho Wolfman]

Somehow I missed posting this?
These are the 2 vents.

 

[Gus1957]

TY. Interesting. Since my tractor sits outside I'm on my 2nd tractor seat that is falling apart. I usually throw a dry feed bag on it before getting on. And when I do water dumps out the bottom of it. I've got to check that vent area under it.