I have a 1999 763F. During the Summer I installed a factory cab heater (the style that sits on the rear cab wall by the operator's left shoulder, Red Dot Model 2020). At the time I thought that it was putting out sufficient warm air, but now that Winter is here that is not the case. I may have the direction of the water flow wrong. The flow through the actual heater is good when checked with a garden hose connected to it. Can anyone let me know which port on top of the engine is the discharge (pressure) to the heater core and which one is the suction back to the engine. If you know which port on the actual heater is the inlet/suction that would also be very helpful. I've installed a 12 volt inline pump to assist the flow to the heater because the heater core sits above the engine as well as a capped tee by the heater core to allow bleeding the air from the line Thanks in advance for any advice on the issue.