m444 suddenly lost hydraulics

[mightymouse]

Was moving snow for about 30 minutes with no issues then suddenly lost all hydraulics. No obvious leaks. Motor to pump coupler is engaged and turning pump. Fluid level is ok. How can i test the pump? What is the best path for troubleshooting? Why do these break downs always happen during a blizzard? Thank you for the help

 

[mightymouse]

I removed the vacuum gauge plug from the oil filter housing and ran the engine. There was no hydraulic fluid movement. I'm guessing the hydraulic pump is out? I will remove the pump tomorrow and take a look.

 

[Tazza]

I removed the vacuum gauge plug from the oil filter housing and ran the engine. There was no hydraulic fluid movement. I'm guessing the hydraulic pump is out? I will remove the pump tomorrow and take a look.

It does sound like the pump or the linkage to the pump is broken. I know the pump for 74x series, the splines that engage the pump are quite small and do fail.