cooling fan will not come on and engine overheats
If all your hydraulic functions (drive, loader, bucket) work then I would be looking at the fan motor and possibly the charge pump (I think its the last pump in the stack, which would be the one closest to the front of the machine). Charge oil flows through the fan motor first on its way to the system. Normally the fan defaults to 100% in the event of a fan solenoid failure. I suppose its possible debris could have jammed the bypass wide open somehow. The other possibility would be that the charge pump or its shaft splines have failed. I would think you would see some issues with the hydrostatic drive system if you had no charge pump pressure. If you put up your serial number someone with SIS might be able to get you some more precise info.
He's confused the issue by creating a new thread. See here.......... HeavyEquipmentForums
Nige I created a new thread because I did not want to confuse the issue. This unit now has a brand new charge and hyd pump that fixed the other issue. Now, 92U you say debris could be blocking the bypass wide open, that could be because the old pump cratered and left my hyd filter looking like a silver mine
sn# 0272DPB5W00489
I understand that, but by not giving the back story behind how you got to this point you sent the hounds off on a false trail........... Did you do a full system cleanout when the pump was replaced.? That would be remove all hoses and hydraulic cylinders stripped, main control valve disassembled & cleaned, drive motors cleaned out, plus all the secondary valves - solenoid or otherwise. It's a major job, almost requires the whole machine to be disassembled. I'm guessing that you didn't. Try pulling the new hydraulic filter. I'm guessing you'll find a significant quantity of sparklies in it. I'm hoping the remaining contamination in the system hasn't taken your new pumps out yet.
If my memory serves correct the charge oil runs through the fan before it hits the filter. If you didn't remove and flush the hydraulic tank I wouldn't doubt some sparkles made it past the in tank pickup strainer.
In the process of trying to pull the bypass valve now but am gonna have to modify my 1 i/4 socket because it is not deep enough to clear the stem of the valve.