Hello all. I have a cat 615 that an operator turned over. It was upside down for about 6hrs before i could get it back on its wheels. I did let it set for a couple of months. I replaced many brackets, lines and hoses on top of the neck. I started the machine and it started right up and sounds normal at idle. The steering would only turn left. I removed steering servo. the slide was stuck. cleaned it and reinstalled. I tested the machine and noticed it would not rev up. It seems to be in a strain. i drove the machine about 2 miles it its current location. It still sounded very much in a strain. water temp and oil pressure normal. Started trouble shooting problem. Checked turbo to see if it was struck or tight. Seemed to be normal. Removed aftercooler cleaned and reinstalled. started again with no no filter or muffler. was the same great idle but will not rev up. Removed injection pump had it built and reinstalled. test again same. I thought it could be restriction of hyd returning to the tank, so i have removed and checked all implement relief valves. All move free and look good. hyd fluid seems to be getting hot. All functions work and trans gears work. Does anyone have any ideas where to go from here go from here? Could it be in the torque converter? Pump vanes stuck? Thanks for any help!
Couple of things come to mind. Is the oil pressure high enough to allow the governor idle stop to retract and allow the engine to rev up? Does the engine have a Air/Fuel Ratio Controller? A bad diaphragm in the controller will affect rpm.
thanks for the reply, I will get a mechanical oil pressure gauge and install. I'm not sure on the controller. it is a 46z machine. i will look in my service manual. is it part of the injection pump. thanks again for your help. I never thought of oil pressure. The over head was oiling pretty good at idle. So i ASSUMED it was good.
If your hydraulic oil is getting hot and it seems to be in a strain, you have a hydraulic valve stuck somewhere causing the pressure to be directed through a relief valve or deadheading. Hydraulic seat valve, cushion hitch, implement controls, lift and lower, steering, eject... Did it bend a pressure hose or kink it? The 621s had the pumps driven off the transmission gears, not sure how the 615s were driven.
Thanks, I have taken out all the relief valves that I can find in the shop manual. They seem to fine. I did install an oil pressure gage and discovered it is over 100 psi. Could that relief valve be stuck. Maybe the hyd was getting hot when I tried using the machine at a very low rim. Thanks again