Cat 950 SN 81J Fuel Issues

Cat 950 3304 engine

I am getting air in the fuel system after the machine sits for a few days. I have replaced the rubber lines, connections look good, new fuel filter, plus a new priming pump. Question, Is there any kind of a check valve on the pump that can be changed in the field. Once running the machine operates as normal. Any comments will be appreciated very much. Thank you Ray

Pretty sure those utilize a residual check valve to keep fuel from bleeding back to the tank. I think there’s a couple different styles depending on what style pump you have. Your parts book should break that out for you or contact your local dealer parts department. I believe the non sleeve metering pumps used a plastic check valve and spring under the side cover of the pump. Good luck!