8011 hydraulics don't lift loads when hot

Hi All:
New here and of course have a problem. Here are the symptoms:

Upon startup, cold 3pth will not lift. Place nose of tractor down and it will lift (prime?)

When worked (ploughing, or no till drill) 3pth lifts slow then will not have power to lift plough (KV 4 furrow).

It has light oil in hydraulic system TDF type.

I was thinking:
Replace oil with 90-140 going thicker than the 80wt recommended.

Pull pump and reface sides of gear pump to up pressure.

Or could it be a leaking lift cylinder. I don't think so because the remotes get slow and lack lifting power too.

Any suggrstions would be very welcome.
Ken

The oil pump on the UR2 chassis is mounted behind the clutch housing, so the oil level must be low.
top up the oil before the oil pump wears out.

Dont reface an oil pump, replacement is more reliable with less work and cost. These pumps can be bought for 250 Euro grey market, and even cheaper if you buy them directly from Zetor's subcontractor in Poland.

Renze:

Thanks for your interest. I pulled the pump and have one on order. I did open it up for a looksee. Lots of side play in the drive shaft and quite a bit of end play on the gears. It must just sit and spin in the oil and have little or no suck and low pressure when it does pick up the oil. Short of a lot of milling and fiddling I think replacing it is the way to go. I could put in thick oil but it never would be right and in the middle of no-till work I don't need problems.

I pick up the pump wed and it should be in by the weekend so I'll let you know.

Do not run the thicker gear oil as it will cause all sorts of problems long term.

Renze:

I went for the new pump. Aftermarket from Poland. Of course a little trouble in paradise!

1 the lower pickup turbe from pump to housing was too big on one end so that was a while getting a fit. But, alas, pump is in.

2 Pressure pipe that threads into the new pump won't go in without grinding off a bump on the tractor casting. ( unless they make more than one adaptor kit) But it will go.

3 Once in this pipe will not adapt to the tractor pressure line without its length being reduced. A cut, clean, fit and braze adventure. ( unless they make more than one adaptor kit) or I got the wrong one.

Could I have been given the wrong adaptor kit? The lower elbow for the pump pickup after a little work went in well and that part is okay it too was in the adaptor kit.

Hmmmmmmm

What did you pay for it ?

$335 cdn plus tax, plus adaptor kit $45cnd.

The pump is in but not hooked up to tractor steel line. I see the line is rigid and very hard to take off (battery box, battery removal etc) If I did and cut and re-brazed ball end it would have to be exact in length as there is no lateral movement of the rigid line nor flex in the Sparex adaptor pipe and fitting.

I'm off to a hydraulic shop to see if they can make up a hose with the male end going into the pump, the hose (about 18" ) coming out of the pump housing and going to the existing steel tractor line with a female end to screw into its existing fitting. Doing it this way I avoid: grinding tractor case, shortening steel line and eliminate two unions. Your thoughts?

The Sparex adaptor kit is looking more like a paper weight.
Hope this will help others. Oh, my tractor is stock with no previous hydraulic mods, I am the second owner.

New aftermarket pump in and working fine. A great improvement in lift speed and capacity. No delay when starting tractor. Using TDH fluid.

Took a chance with Sparex adaptor kit (had to buy copper washers, not with kit). Measured, cut and brazed ball end on original presssure line from pump. Got lucky. This is not just a bolt on kit, you must custom fit the pressure line ( it is too long). This means removal of, or shortening and brazing in place, the pressure line that feeds the hydraulics.

Good luck to all that must go this route.