Hydraulic oil temp

[Donm560]

I am having a problem with my bx1800 mower stopping mowing (mid pto shaft stops turning) after about 30 minutes of mowing. I have rebuilt PTO clutch and replaced fluids and filter. It seems to only do this in temps above about 85 degrees. Was told by a tech this is due to high hydraulic fluid temp causing PTO pressure valve to allow bypass. I have replaced the PTO bypass spring and ball at the fluid filter. Was thinking about extending and looping a hydraulic hose to hopefully allow more cooling of the transmission fluid? Could this help and if so which hose would be best to extend?
TIA
Don

 

[Edke6bnl]

could you add an oil cooler with fan to the return side?

 

[85Hokie]

I am having a problem with my bx1800 mower stopping mowing (mid pto shaft stops turning) after about 30 minutes of mowing. I have rebuilt PTO clutch and replaced fluids and filter. It seems to only do this in temps above about 85 degrees. Was told by a tech this is due to high hydraulic fluid temp causing PTO pressure valve to allow bypass. I have replaced the PTO bypass spring and ball at the fluid filter. Was thinking about extending and looping a hydraulic hose to hopefully allow more cooling of the transmission fluid? Could this help and if so which hose would be best to extend?
TIA
Don

What hydraulic oil are you using? S-UDT2?

 

[Hkb82]

I think by extending the hose you’re only gonna extend your run time by about 3 min. I’d be trying to find the culprit of the issue instead of a bypass to the problem.

 

[TheOldHokie]

I am having a problem with my bx1800 mower stopping mowing (mid pto shaft stops turning) after about 30 minutes of mowing. I have rebuilt PTO clutch and replaced fluids and filter. It seems to only do this in temps above about 85 degrees. Was told by a tech this is due to high hydraulic fluid temp causing PTO pressure valve to allow bypass. I have replaced the PTO bypass spring and ball at the fluid filter. Was thinking about extending and looping a hydraulic hose to hopefully allow more cooling of the transmission fluid? Could this help and if so which hose would be best to extend?
TIA
Don

I think I would be verifying the pressure loss is coming from the rrlief valve with an actual measurement. Relief valves are mighty reliable positive shutoff devices.

Dan

 

[JimDeL]

Is the fan intact?

 

[Dan Australia]

Hi Don,

Wondering if you found your problem as I'm having the same thing happening?

Cheerss,
Dan

 

[Donm560]

I have not found the problem yet, bought a gauge and fitting to check the pressure but haven't gotten to that yet. Was thinking about extending the hose with a metal section for cooling. My fluid is the UDT2 that Kubota calls to be used in that particular model and the fan appears to be working fine. I hope to check the pressure before going further but would like for it to be warmer to reproduce the conditions as in cooler weather it seems to work fine.

 

[North Idaho Wolfman]

Hi Don,

Wondering if you found your problem as I'm having the same thing happening?

Cheerss,
Dan

Comparing issues on a BX2360 to a BX1800 is quite a leap, there is a ton of differences in those 2 models.

You might want to start your own thread on it.