What Happens When a Hydraulic Pump Can't Get Oil

[Winmac]

It's unlikely a frozen sump would cause this but if the oil in the pump was frozen, it's possible.

 

[David_Kb7uns]

Some Grand L series Kubota tractors had a problem when using tractor for extended periods of time with a front down attitude down a hill or such the pump drive gear and shaft were starved of oil and the pump drive shaft would shear off The Kubota fix was to put on a new pump holder with a port drilled between the gear and bearings with a supply line with restrictor coming off a new oil filter holder. So do check the pump drive shaft and bearings also there could be a problem there.

David Kb7uns

 

[Industrial Toys]

It seems that the damage was limited to a sheared off key. No bigggie, but I am stilll curious why. The tractor worked fine, was parked overnight in very cold conditions and then failed on start up.

 

[J_J]

Well now, can a frozen pump even turn?

Perhaps the pump froze because of some water in the fluid. The engine would turn over, but the shaft might shear off or strip the gears.

 

[Industrial Toys]

He did report that his hyd fluid was very milky and he intends to change it.