06 losing prime in fuel system

Air bubbles means it is sucking air. Check for rubber bits and pieces in fuel filters/housing, if so you will need to replace fuel line. if none, with the motor running you can take a can of starting fluid and spray around fuel line/filter mating surfaces and if a leak is found the motor should rev-up.

 

This happened once to me earlier this year, problem was the rubber gasket on the secondary fuel filter not being seated quite right and allowing air in. Did this happen immediately after a PM? That is what happened to my truck. Good luck, Jim

 

Bad fuel filter or separator. Like someone said air bubbles so you are sucking air. Change both again i would say.

 

fuel/water seperator has a check valve on the front side that sticks open pretty common. also if ou have leakage at the cups that can cause air in fuel issue, check out that valve first, then have the clear lines hooked up to the front of the head and check out the cups.

 

If injector cups leak you are gonna get fuel in your coolant tank also.

 

This will not make the engine rev, your thinki

THIS WILL NOT MAKE A DIESEL REV, your thinking of a car with a gas motor and that only works a the vacuum lines.

 

I am having issues finding where the air is getting in on a 2012 Mack CXU613 MP8. Any tips or advice?