Recently purchased a 1993 743B . As winter is quickly approaching, trying out the cab heater, but no heat! Had the machine running, top rad hose hot, but lines to heater ice cold. Tilted up the cab , bleed air from heater, still no heat. Just drained antifreeze, flushed out lines, water running freely. Had talked with the dealer, he had told me that this model has poor heat. I had cranked engine over with thermostat out, filled with water, it pushed out about 1" of water, and no more. Do these Kubota's have weak water pumps? Anyone out there with the same machine? Please advise