QuestionQUESTION: Hi Arnie, Thanks for volunteering to take questions. I do look forward to your reply!
This Case 2390 has lost hydraulic pressure all together. Nothing that is powered via the hydraulics works. No 3 pt, no clutch, etc.
I'm thinking the pump has gone bad. Does that sound right?
Is it possible that an oil pickup screen is plugged?
Since the hydraulics are totally inoperative I didn't think that was it.
How hard is it to either repair or replace the pump on this tractor?
I can get a used pump but they are not cheap.
Thanks! Dave
ANSWER: Hello,
The pressure flow compensated hydraulics on these tractors take some detective work to properly diagnose. First of all, does the steering work because that is supplied by a separate pump. If nothing works including the steering, then it's possible that the gears that drive the pumps have failed and the pumps are not turning. You can verify by taking the small gear pump off the end of the large piston pump and cranking the engine over to see if the shaft turns. To check if it's starving for oil, you would have to install a gauge in the tube between the charge pump and the piston pump. The gauge screws in where the pressure sending unit goes. There should be about 25-30 psi charge pressure with a minumum of 15 psi when there is flow being used out the remote valves. If there is no charge pressure, the charge pump may have failed or the key may have sheared if the shaft is turning in the check procedure previously mentioned. The charge pump is located inside the transmission housing behind the piston pump. The piston pump has to be removed to pull it out. Besides the hydraulic filters, there is a suction screen inside the transmission housing, but the tractor would have to be split between the transmission and rear end to get at it. If charge pressure is OK, then there has to be about 600 psi low pressure standby from the piston pump. The line has to be removed from the compensator valve and capped off, and a gauge installed in one of the remotes to check it. It's possible the compensator valve has a broken spring or some other problem. Last but not least, the piston pump. There is really no way to check it other than to remove it and take it apart to inspect it.
Good luck.
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QUESTION: Arnie, one more question if I could....
These Case tractors engines in the 2390 .. when do they typically need to be rebuilt. Is 6000 hours getting close? This engine runs ok with no smoking when it runs.
Thanks, Dave
Answer It has always been a pretty reliable engine and was used in many models for many years. When it is due for an overhaul depends on alot of variables such as how hard it was worked and how well it was maintained, so there really is no good answer that I can give. I have seen engines with less than 3,000 hrs that were in pretty sad shape and needed to be completely rebuilt. I have also seen some with as much as 9,000 hrs that were still in pretty decent shape and had never been apart. If it runs good, and doesn't smoke or use oil, get as much life out of it as you can.
