L4060 Lost all Hydraulics, No steering, No Drive - Pump sounds like it's cavitating?

[Joematys]

Hi all, new to this forum.. owned an old new holland my whole life.. This is our second year with our 2017 Kubota L4060. After warming it up this morning ( outside) backed it up and all the hydraulics went dead. Lots of fluid and clean.. It shows many air bubbles on it if you let it idle, in the fluid that is. The hydraulics will slowly and jittery intermittently move the tractor back and forth and control everything but the steering.. The pump sounds as if it is sucking air or low on fluid. If you rev it up at all it does nothing. On the display it no longer shows range position L, M,H and the auto throttle will no longer work.. And for some reason when you turn the key it only turns over to start once in a while now?? Any ideas?? ECU?

Many symptoms after one small 10' expedition in reverse.

Thanks in advance!!

-Joe

 

[kubotafreak]

The hydraulics are mechanical, with the system operational any time the engine is running. As far as the system cavitating, I would check for any leaks. This is the easiest way to pinpoint air ingress. Knocked off filter base(bottom right), hose before pump, and hoses at the front cooler are suspect. As far as range selection, their is a linkage under the seat pan that has a sensor on it for the gear. I would look and make sure the linkage is not bent/ripped off. The starting if HST is very sensitive for pedal neutral. So don't rest your foot on the pedal when starting. If you have a third function, these fittings under the loader frame are very vulnerable to being damaged as well.

 

[85Hokie]

I would find the return TO THE pump..... somewhere you are sucking in air

 

[lugbolt]

the pump is on the side of the engine. RH side as you are sitting on it. It has a large diameter suction pipe that goes to it, and that pipe has a rubber elbow that connects the pipe to the pump. The pipe and the rubber coupler are the suction side of the pump and is a possible culprit (hole in the rubber part). Run your hand around the back side of the rubber hose and see if you feel any wetness or cracking or holes. If you find a leak there (it'll be an air leak more than a fluid leak) replace it. If no leaks are found start the engine and observe that rubber hose. Does it collapse? If it does, you have a restriction on the suction side of the system-meaning likely contaminated fluid or plugged filters.

 

[Joematys]

Appreciate everybody's help! Rubber return line connector had a split in it going into the pump. Works now!

 

[ACDII]

Isn't it great when it is something simple and cheap!

 

[kubotafreak]

Please see the attached for the hst range calibration. The directions are very specific, you must meet all the starting constraints, and follow the instructions to the letter.

 

[Joematys]

Isn't it great when it is something simple and cheap!

Gotta love it when you win!!