3 PT Hitch Piston Repair

[ScottyChip]

Hi All

I am looking for some help and advice. My 3pt hitch arms slowly sink, when using tractor at 1800 rpm, at idle or when shutdown. I have been told that it may be the o-rings around the 3 pt piston.
My question, is this a repair that a handy man mechanic can tackle?
I have no problem doing major repairs on lab equipment at work, but have never tackled tractor / automotive type repairs.
Are there any special tools that I may need, should my work area be really clean?
Here is a schematic of the area.
Thanks, ScottyChip

 

[HydroTek]

Clean is always good, but "clean room" clean is not necessary. Nothing difficult about replacing piston O-rings, tho I usually see a chip or other particle in the control valve that is the cause of drift.
Use caution when taking anything anything off the control valve, some of the adjustments are sensitive. You can measure or count turns if you remove a valve spool.
An old mechanic I worked with, would say "He ain't got nothing like it is, so go in like you intend to fix it ..or leave it alone"

 

[ScottyChip]

Thanks HydroTek.

If never occurred to me that the control valve may be the problem. Is there anything that I can do to narrow it down? other symptoms that might point me to the source of the problem?

 

[kebo]

I guess you've checked your rockshaft valve adjustment? You probably realize that it controls the rate of descent of your attachment so it could be set wrong.

I can't tell you how to determine the exact cause of your problem (assuming the rockshaft valve is correct and you have proper hyd fluid level), but it would be good to know what's wrong before you tear into it. On some of the older tractors, there is an inspection port on the side of the tunnel that you can remove and look inside, while the lift is up. (Obviously just look with flexible lights and mirrors, no hands inside!) Sometimes you can see where it may be leaking from, such as the standpipe, or maybe from beneath the piston. But, that applied to the older MF's, it doesn't really look like you have one on yours. Good luck!

 

[Soundguy]

not sure what tractor you have.. but on old fors.. a lil clean is all you need. heck.. I've pulled lift cover and flipped them over onto the tire and rebuilt them right there..


soundguy

 

[HydroTek]

Thanks HydroTek.

If never occurred to me that the control valve may be the problem. Is there anything that I can do to narrow it down? other symptoms that might point me to the source of the problem?

Nope ..Kubota didn't provide any way to see inside the housing to look for leaks. Two strong men can lift the housing out by hand, not really that heavy, just a bit awkward to handle, two can keep from pinching fingers All valving for this unit is located under the 3pt housing ..gonna have to get in there.

Kebo that works fine on older MF tractors for sure, but not on this one.

Soundguy Yup ..been there, done that one too

 

[mjncad]

ScottyChip:

I don't know if you're close to Bay Robert's or not; but if so and you don't want to tackle this repair or let the dealer do it; you might contact Paul Short at Specialty Repairs.

Paul's' skills are second to none.

 

[ScottyChip]

To answer a couple of questions, I am going to assume that the rockshaft valve is the one under the seat used to adjust how quickly the 3 pt hitch drops? If I close it completely the 3pt hitch still drops. Hydraulic fliud is find, I keep checking thinking that if it drops I have found the source of my problem.
Thanks, mjncad, I am about an 45 minutes drive from Bay Roberts, the dealer is only about a few minutes drive.
Do you guys think I can do more damage by not doing a repair? will the hydraulic pump have to work harder if there is a constant slow leak?

 

[HydroTek]

To answer a couple of questions, I am going to assume that the rockshaft valve is the one under the seat used to adjust how quickly the 3 pt hitch drops? If I close it completely the 3pt hitch still drops. Hydraulic fliud is find, I keep checking thinking that if it drops I have found the source of my problem.
Thanks, mjncad, I am about an 45 minutes drive from Bay Roberts, the dealer is only about a few minutes drive.
Do you guys think I can do more damage by not doing a repair? will the hydraulic pump have to work harder if there is a constant slow leak?

Your Kubota has an internal lift cylinder, when you close the drop rate valve, you isolate the lift valve from the circuit. sounds like a sure thing that you have a leak at the lift cylinder. The seal is pretty easy to replace, if that is the problem.
.