cojack4646 Report post Posted April 20, 2014 Pump has been replace 3 times, why do pump keep going out? System flush, still have same problem. Share this post Link to post Share on other sites
wolfe10 Report post Posted April 20, 2014 coijack4646, Welcome to the FMCA Forum. #1 killer of HEUI pumps is low fuel pressure. This occurred most frequently on those chassis with a single fuel filter (2 micron element) which restricted fuel flow a LOT quicker than the two filter systems with a 10 or 30 micron element followed by a 2 micron element. An air leak on the suction side of the lift pump will have the same effect with lower PSI to the HEUI pump. But, three failures is really difficult to understand. Be sure they check fuel pressure from the lift pump -- heck even a pinched fuel hose could create a hard time for the pump. Share this post Link to post Share on other sites
