TC33D Hydraulic Power Problems

[jw1965]

First off, brand new here so if I am doing this wrong, let me know.

We have a New Holland TC33D, Hydrostatic, year 1999 I believe. Great tractor, love it, never had an issue until 2 summers ago. We lent it to the neighbor and when we got it back we noticed a loss of power. We had to turn the flat head screw on the bypass valve on passenger side frame to shift power to either the front or back. We can't run the 3-point rear hitch and the loader at the same time. Never touched this valve the first 6-8 years so clearly something changed. We replaced this bypass valve and still no change. When mowing we turn the screw as far as we can to get the most power but still have enough to lift the mower. The tractor lacks a lot of power mowing...or any other time. The fluid and filter is changed every year. We had it to local New Holland dealer and can't remember what he did but it didn't fix it. We are baffled. Is there a pressure valve, by-pass valve or something that was tripped or needs replaced? Any help? Thanks Jeff.

 

[Spicer]

Jeff,

I believe you are talking about the diverter valve.
If you have a front end loader turn the screw to the 11 O'clock position and if no loader is present then turn it to the 1 O'clock position.

Important:
While testing lower the three point hitch to eliminate any problems with the HPL valve.

Mike

 

[jw1965]

Mike, what is really weird is that we didn't even now the diverter valve was on the tractor. We hooked up loader, Mid Mower, rototiller...all never touching the valve and always had full power. Now even moving the screw back to 1:00 it barely has enough power to get itself up the hill let alone plowing snow or mowing at the same time. Very frustrated with it.

 

[paine]

Any luck with figuring out your problem?

 

[jw1965]

No not yet. It's very frustrating. Any suggestions? We have used filters from Napa every year for maintenance...wondering if that is an issue...

 

[J_J]

Mike, what is really weird is that we didn't even now the diverter valve was on the tractor. We hooked up loader, Mid Mower, rototiller...all never touching the valve and always had full power. Now even moving the screw back to 1:00 it barely has enough power to get itself up the hill let alone plowing snow or mowing at the same time. Very frustrated with it.

My Kubota has a similar valve called the hyd blk.

If no loader, the screw is one way, and if loader is installed the screw is in another position.

You screw may be half position, and routing half of the flow to the loader and the other half of the flow to the 3pt.

Try turning the screw max left and see if the 3pt only operates, or both the 3pt and the loader work.

If your pump is good, and full engine speed, the pump will put out full GPM, and the flow has to go somewhere.

A flow meter and pressure gage will tell you a lot about your hyd system.

If yo have a weak hyd system, it could be the pump, or valve, and if only the component is weak, it might be the component like a cyl seals, or motor seals, etc.

A good Hyd gauge is necessary to troubleshoot and monitor the hyd system.

If you know pump flow and the engine is at max, remove a loader cyl hose and place in a bucket and measure flow, and if it is half, maybe that screw is mid way.