I have a 1992 Case 590 Turbo. When I start it and run it, it has full power as it always had. After about 1 hour of loader use, it starts losing power and will no longer push dirt and it barely will move forward or back. My suspicion is the pump in the torque converter is going bad, i.e., when the fluid gets hot, it is thinner and the pump has a harder time moving fluid and keeping pressure up. Is this the correct assumption? Also, if I have the pump replaced, should I go ahead and have the torque converter replaced too?
It could be the torque converter and I'd replace the pump at the same time . It's a 4.5 hr. job.
It sounds like you are correct about the pump. You probably need to check trans pressure to make sure though. Also does the engine bogg down or does it rev up when machine looses power?
Also when it looses power, check the fluid on the dipstick for aeration. That also could cause your symptoms.
I am able to rev the engine when it looses power but it doesn't help increase the power. Engine doesn't seem to bogg down, I have full control of the throttle even when it is losing power. I guess I need to tell you that the power is lost slowly over a period of about 30 minutes after I run it for about an hour.
Then I would suggest you test your pump pressure.