I have a 1997 750C Series 1 that was throwing a F640 Hydrostatic Pump Speed Sensor Fault. It would run for about 10 minutes then shut down completely. RDO said it was the B14 Hydrostatic pump speed sensor on the front Hydro pump. We replaced the speed sensor and cleared the code. It pushed great for about 20 mins then shut down again but this time it didn't through a code. Any ideas? Thanks.
There's a process to tightening the speed sensors on those machines you have to bottom them out and back them out a half a turn and then tighten collar nut, sometimes you have to play with the sensors either slightly further in or slightly further out.