Super C Touch Control Problem

I'm working on a Super C for a friend and am not experienced with these tractors at all. I finally got it running after about 40-hrs of work. The hydraulic system does not work. The pump is getting, what I consider, very hot. Hot enough you can't touch it without burning yourself. Is this high temp normal? Any suggestions on where to start for troubleshooting?

Have you checked for hydraulic fluid in the system? You fill the system on the left side of the Touch Control unit under the fuel tank through a hex head plug which is about 1" across the flats. Is there evidence of leaking fluid anywhere on the system? The pump also has a main leak path through an o-ring on the front shaft into the crankcase. You will need to provide more information as to what works if anything after checking for fluid in the system. Hope this gets you started, Hal.

Hal; thanks for the reply. The hydraulic fluid is within 1/2" of the filler plug. No evidence of leaking fluid. All linkage appears to be fine and functional. I noted the fluid in the reservoir did not warm up with the engine (temp gauge is broken, but I felt the fluid with my finger). Pump is hot. Is this normal?

Pump should not be hot unless the hydraulics are working really hard. If the engine is laboring and the pump is hot, then that indicates that something is stopped up, or the system needs adjustment. The stops on the system are supposed to be set so that when the rockshaft arms reach the set point with the levers, that the control valve relieves the pressure from the pump. It sounds like the pump is under pressure all the time causing it to overheat. When the system is not active, the pump should only be circulating the fluid without pressure. There are some plugs on the hydraulic manifold where it attaches to the reservoir. You can remove one of those and put in a pressure gage to see what is going on.

Haas; thanks, makes sense. Engine has been a little hard starting and seemed to be laboring a little. Like I said I have no experience with these tractors so I'm blind and don't know what "normal" is. I'll be out in the shop today checking that out. You mentioned adjustments; are there any reference manuals/schematics for the hydraulic system? The owners manual only covers usage and basic maintenance. The I&T Manual has nothing on the touch control system.

I sent you an email so let me know if you don't receive it, Hal.

Here"s the latest. Thanks a million Hal

Symptoms:
1) Engine cranks harder then it should. Not bad, but you can tell something is not right.
2) Hydraulic Pump gets VERY hot VERY quick after starting engine (within 15 seconds).
3) Rocker arms don"t move at all.

Purchased a hydraulic pressure gauge 0-3000 psi, 2" hydraulic hose with 1/4" fittings on each end.

Performed the touch-control test procedures precisely IAW the Service Manual with a load of 300 lbs on the rocker arms.

Started the tractor and the pressure pegged my gauge at 3000 psi. Immediately shut off the tractor and cleaned out my shorts! Gauge didn"t break, but I"m sure the calibration is off a little now? I should have been better prepared for this because I noticed the gauge jumping to about 2500 psi while cranking. Hindsight is when I saw that, I should have put on a gauge with a higher psi rating.

Took the load off the rocker arms and restarted the tractor. Hydraulic pressure started at approx 2500 psi then steadily dropped to 475 psi over about a 30 second period. As the pressure dropped you could hear the engine idle increase as it wasn't laboring as much. Pressure remained at 475 for a little over a minute so I shut her down as the hydraulic pump was smoking hot. IAW the book pressure, without a load on, should be in the 15-40 lb range.

Diagnosis: Faulty safety valve. Hydraulic pump works well.

So I guess my next step is to purchase rebuild parts and proceed with a hydraulic cylinder block rebuild.

I"m open to suggestions if anyone has experience with this.

Thanks;
T.Brown