YM2000 Hydraulics stuck in up position

wombat · Aug 27, 2007

G'day folks.
I've got a bit of a problem with the little Yanny this week.

I drilled some post holes for my neighbor on Sunday
The soil was hard and we had been putting some extra weight on the PHD by lowering his FEL bucket onto it. This worked a treat but may have overworked the yannys hydraulics.
When I headed home I noticed that the implement was stuck at the top of its travel.
When I got home I tried to lower the PHD unsuccessfully so I switched the tractor off and still couldn't lower it. It will usually bleed down for me.

Also when I tried to start the tractor again there was a "whirring" noise coming from the gearbox, the tractor didn't want to run and it soon flattenned the battery.

The piston that sticks out of the back of the pushrod assembly floats free instead of being "spring loaded". ie I can push it in and it stays in.

I've got a manual and figure it's the spool, the stop valve or the piston that is seized.

I'll be pulling it down this week when I get back down the farm[I live 200km away].

Any tips or suggestions?
The oil was changed for new gearbox/hydaulic oil 20 hours ago.
I cleaned the screen at that time. It was filthy.
No obvious leaks.
Will the spool spit ballbearing allove the place when I pull it out.
Any special tools required?

Thanks for any help.

wombat · Aug 31, 2007

OK so I got down to the farm yesterday.

The 3point arms had dropped down so the hydraulics had depressurised.

I pulled the top off the hydraulics and the spool was stuck in the bore.

I tapped it out with a brass punch and polished it lightly inside and out with some very fine wet and dry sandpaper.

It went back in and moved freely.

I replaced the O-rings and put it all back together.

Battery is still flat so I haven't had a chance to see if that's the only thing wrong.

Wombat

wombat · Sep 9, 2007

Got back to the farm this weekend with a new battery.
75AH, 700cca.
Started up first time with lots of cranking power.
Hydraulics worked like a charm. Seemed smoother than before but that might have been wishful thinking.
Hitched up the 5' tiller and cleaned up the vegetable patch.
Planted Spuds, sweet potato and onions.
That tiller is my heaviest implement and the tractor had no problems.
The drop speed adjuster is a lot easier to adjust now that it has been cleaned and a new O ring put in.
It's so easy working on this tractor.

Thanks for listening

Wombat