Mower woes

[kuboman]

I just bought a new GF1800 front mount mower, everything works great except.
After everything gets warmed up the pto will momentarily shut off when I raise the mower deck and then re-engage. I believe this is the same drive train they use on some of the smaller BX tractors. Just wondering if anyone else has had a similar problem and if so what was done to correct it.
I just want a little info before I go hassle the dealer for warranty work.

 

[David_Kb7uns]

I am guessing, but since it has a hydraulic PTO clutch and it looses pressure to clutch when using other hydraulic functions, you should be looking at a restriction in flow at the hydraulic filter or maybe wrong fluid viscosity. Check to make sure that you are using a Kubota hydro filters and Super UDT or I think Premium UDT up north.

David Kb7uns

 

[kuboman]

I am guessing, but since it has a hydraulic PTO clutch and it looses pressure to clutch when using other hydraulic functions, you should be looking at a restriction in flow at the hydraulic filter or maybe wrong fluid viscosity. Check to make sure that you are using a Kubota hydro filters and Super UDT or I think Premium UDT up north.

David Kb7uns

I bought it new this spring so it should have the proper oil in it.
Possible that the charge pump is weak or a valve is sticking.

 

[David_Kb7uns]

Not sure if it is like a BX where there is a priority flow valve that may not be working right. But the not working until warm would make me look at filter flow or too thick of oil still.

David Kb7uns

 

[kuboman]

Well I need to clarify. The pto shuts off even with cold oil, it is worse with warm oil. I also discovered that the mower deck lift is weak too so I am thinking the main relief is weak and needs to be set up.

 

[oldnslo]

Well I need to clarify. The pto shuts off even with cold oil, it is worse with warm oil. I also discovered that the mower deck lift is weak too so I am thinking the main relief is weak and needs to be set up.

If this is new I would have the dealer fix it. Some dealers are real quick to blame you and try to get out of warranty work.

I am not familiar with the GF series but do they have a seperate pump for lifting the mower deck or are all of the functions driven off of the charge pump circuit? If charge pump stop using it until the problem is resolved. If you are not getting proper charge to the HST it will be severely damaged in a short amount of time.

Roy

 

[kuboman]

If this is new I would have the dealer fix it. Some dealers are real quick to blame you and try to get out of warranty work.

I am not familiar with the GF series but do they have a seperate pump for lifting the mower deck or are all of the functions driven off of the charge pump circuit? If charge pump stop using it until the problem is resolved. If you are not getting proper charge to the HST it will be severely damaged in a short amount of time.

Roy

It uses the charge pump for the hydraulic functions. I am sure it is fine. I am quite sure is is a simple relief valve fix.

 

[oldnslo]

It uses the charge pump for the hydraulic functions. I am sure it is fine. I am quite sure is is a simple relief valve fix.

If the relief valve is stuck open and you loose flow this would be true. Unless your dealer is hours away why wouldn't you want the dealer to repair this? That way you would have the repair on record so if the PTO fails again their is some history.

Roy

 

[kuboman]

If the relief valve is stuck open and you loose flow this would be true. Unless your dealer is hours away why wouldn't you want the dealer to repair this? That way you would have the repair on record so if the PTO fails again their is some history.

Roy

Well I do want the dealer to repair it but they are balking at the idea. First they argued that anything is the matter now they just won't return my calls. Seems simpler just to repair it myself. If that is how Kubota is for warranty work then I have nothing to lose by doing it myself

 

[EE_Bota]

It uses the charge pump for the hydraulic functions. I am sure it is fine. I am quite sure is is a simple relief valve fix.

Then your system is not like my BX2200 system, unless the relief valve you mention is the PTO relief valve, or unless you main relief valve cannot even hold 68 psi.

Sounds almost like the priority flow valve has lost it's sense of priority. My tractor, the PTO requires almost zero flow and 68 psi. Yet, due to the design of the system, it is entitled to priority flow of 1.8 gpm, potentially at full system pressure, which never really develops because it is relieved by the PTO relief valve at 68psi as hydrostatic makeup flow.