Kubota g1800s lawn tractor weak hydraulics

[straytcat]

Hi all, noob here. I've got a hydraulic problem with my g1800s lawn tractor. It has one single acting cylinder for lifting the deck, and raising and lowering the 46 inch snowblower. It has no problem lifting the deck, and lifting the mounting plate for the snowblower without the snowblower attached.
when I attach the snowblower, it won't lift it off the ground. The hydro drive works well, no issues., Is there a separate pump for the lift, or does all the hydraulics run off the same pump? Thanks.

 

[lmichael]

May just be a simple seal issue

 

[GreensvilleJay]

had a quik look at the parts online....
when was the oil changed and filters cleaned/replaced
is oil level 'full'
check pressure at the cylinder, is it to 'spec'
in Canada ,that SA cylinder is $2,000 !!!!

 

[Hugo Habicht]

Hi,

the lifting cylinder has an extra pump called "auxiliary pump". It sits at the back of the drive pump. The HST drive has it's own pump controlled by the pedal. As far as I remember the auxiliary pump should have a pressure of 35 bar at 1800 rpm.



You find a workshop manual on "kubotabooks.com".

Kind regards,
Hugo

 

[GreensvilleJay]

hmm 35 bar is about 500 PSI

 

[Hugo Habicht]

hmm 35 bar is about 500 PSI

That is correct...

 

[lugbolt]

Use a good quality digital pressure gauge, set the throttle to maximum RPM and read your maximum pressure. Chances are that it'll be on the lower side of spec. You can adjust it using a shim (washer) under the relief spring. If you can't get enough washers in there to get the pressure up to the high end of spec, the pump is probably wore out. Remember these things are 30+ years old now so we cannot expect them to work like new, but we can expect to have to work on them from time to time.

I'm going through this as we speak with my mom's G1800.