CAT 279C Issues

CAT 279C with 4900 hours. Worked the machine clearing brush today for 5 hours or so. The last hour it started to lose power, especially in drive. It would bog down and the machine would barely move and then it would sputter like there was air in the fuel. It stalled a few times. When you start it back up, it has full power and hydraulics for a few minutes then it loses power again. Any ideas? It has a new fuel filter and there is no air or water in the lines.

CAT 279C Issues