674D

If these engines have been maintained properly they will run problem free for many 1000s of hours. My brother has a 454D with the 3 cyl version of that engine and it has over 15,000 hrs and still running great. He also has a 684 with the same D239 and it has 8000 hrs and no problems with the engine. The power brakes and parking brake are more of a problem in that tractor than the engine. If someone drives the tractor with the parking brake on it will chew up the parking brake band which is in the transmission and the band bits will clog up the hydraulic filter. Check for coolant in the oil as if someone overheated it the "O" rings on the sleeves will shrink and crack and leak coolant into the crankcase.

If you do buy it be sure to add a Diesel fuel conditioner/lubricant to the fuel tank as these older Bosch injection pumps relied on the lubrication from the Diesel fuel to lubricate the injection pump but now with the newer low sulphur fuels there is not as much lubrication anymore. The lack of lubrication will cause the front lipseal on the injection pump to wear out and leak Diesel fuel into the crankcase.

JB2