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.
The early "K" series machines had an issue with charge pumps and cooling system, which cause the hydrostats to go out. Some of the series 2's had the same issue. Case had an update on these machines and extended the warranty on the ones that were repaired. Now I'm not saying that your machine is in the serial number range and I can't say that the program is still available but anyway what is going on with yours is it sounds like the hydrostats are bad. Both motors and pumps will have to be rebuilt.
Like a fried of mine would say “jack up the radiator cap and put a new machine under it”
Thank you for the advice. It’s what I was afraid of. When we had the pumps tested, we have no idea how they tested them or for how long or really any information on it. And the company said they had to go threw them before they would test them on their machine, which I figured meant the internals are be good if it passes inspection.. Also, When I was reading the manual, it was saying that there is 2 charge pumps? One inside of each pump? I forgot to add that in the first post. Just curious. Thanks again.
Got one doing the same thing 850 k series 2 would like to know how it turns out
ive got an 850k same problem did you ever figure it out