NEW HOLLAND TL90A AND TL80 HYDRAULIS
- Thread starter TEXAS243
- Start date
It depends a lot on what kind of valve controls your hydraulics on that big of a machine. On a smaller rig I had years ago it was usually some gunk in the spool valve that controlled lift, lower and float. It may be something easier like a worn bypass valve spring or the valve may just be out of adjustment on yours.
I think the hydraulics controls are bad or a bypass is shut off. Change the oil and filter on the tl90 worked good for about an hour then the pump quit working altogether. I sure miss the old ones with the cross valves. I don't know if the value is big enough to handle a 15 ft. I have 2 tn65 with cross valves and the mower hydraulics work fast. I not sure about these new tractors.
TexasAirCooler
Member
Does your's have a flow control under the seat like the smaller tractors?
TL Hydraulics
You said you are using batwing mowers. Anytime you are operating single acting cylinders, as you are to raise/lower the wings, it is necessary to set up the tractor valve for single acting cylinders. It requires backing out a bolt on the tractor control valve. This is explained in the operators manual.
If this is not done, whenever you are lowering the wing it is putting the tractor hydraulic pump in high pressure mode and eventually will ruin the pump. I suspect you may be at that point. To check the pump you need to attach a flow meter to the tractor remotes and see what flow you are getting at zero pressure (say at 1500 ERPM's). Then increase the pressure to 2000 PSI on the flow meter and see what flow you are getting again at 1500 ERPM's. If it is less that 80% of the flow at zero pressure your hydraulic pump is failing.
You said you are using batwing mowers. Anytime you are operating single acting cylinders, as you are to raise/lower the wings, it is necessary to set up the tractor valve for single acting cylinders. It requires backing out a bolt on the tractor control valve. This is explained in the operators manual.
If this is not done, whenever you are lowering the wing it is putting the tractor hydraulic pump in high pressure mode and eventually will ruin the pump. I suspect you may be at that point. To check the pump you need to attach a flow meter to the tractor remotes and see what flow you are getting at zero pressure (say at 1500 ERPM's). Then increase the pressure to 2000 PSI on the flow meter and see what flow you are getting again at 1500 ERPM's. If it is less that 80% of the flow at zero pressure your hydraulic pump is failing.
You might try running your tractors with the hydraulic filler cap off, but not in the dirt. I am having the same problems slow hydraulic response, three point hitch will not lift, front loader slow. I took the filler cap off and drove around in the yard and all hydraulics came back strong. I am thinking that this system on these tractors needs a vent of some sort to keep from having a vacuum in the rear end housings. I was also told that the large suck pipe leading to the hydraulic pump can crack along the seam and will allow the pump to suck air and cause hydraulic problems.
Good luck with a fix
glbmsu
Good luck with a fix
glbmsu