DanDan00
New Member
Case 850K runs strong for about 45 mins to an hr. Charge pressure is around 350-400 when cold. When you start moving it’ll start to drop below 300 but still strong, I can read forward motor pressure is 5000+psi, if you try pushing hard when it’s cold. As you continue to work the machine, and everything warms up, the charge pressure will drop to as low as 125 to where it doesn’t want to push anything but maybe a 1/4 blade, prob even less. And forward pressure is maybe 1000psi. Trans temp will climb tell it’s all the way up to the red. Also, if your just moving around the field, going straight, it will get up to speed, charge pressure will be around 250-300, but as soon as you try to steer, even just a small amount, will cause the charge pump pressure to start dropping. Even far enough to make the dozer stop in its turn. If it’s really hot, it’ll just slow down and almost not want to turn. We have disconnected and caped the brake circuit, no change. We sent the 2 pumps out and had them checked, they said all was good. Found one motor had excessive case drain, changed that motor, still no change. Changed the filters 2 times and the hydraulic fluid. Cut the filter open, found nothing Checked the pre-screen in the tank. No metal was found.
Also, With the parking brake set, levers up, charge pressure will be at 125 at idle. If you release the brakes, levers down, it’ll climb to 300-350psi at idle. But if you place the machine in forward or reverse, it’ll drop back down to 175 ish pressure at idle. I’m suspecting a bad charge pump, but don’t want to throw anymore parts at it.
Also, With the parking brake set, levers up, charge pressure will be at 125 at idle. If you release the brakes, levers down, it’ll climb to 300-350psi at idle. But if you place the machine in forward or reverse, it’ll drop back down to 175 ish pressure at idle. I’m suspecting a bad charge pump, but don’t want to throw anymore parts at it.
