How do you bleed air out of a 12 valve Cummins?
To bleed the system, first make sure you have at least 5 gallons of fuel in the tank, do not trust the gauge. Then locate the bleed bolt on the top of the fuel filter housing and loosen it. Now locate the primer on the lift pump. Pump the Primer on the lift pump until bubble free air comes out of the bleed bolt.
What to do if your Cummins engine won’t start?
Engine won’t start: Bleed the air out of the system If you are starting your Cummins for the first time, it is required to “bleed” the air out of the injector lines by loosening the injector line nut just enough to allow fuel and air to escape the line while you are cranking the engine. It is usually required to do at least 3 injector lines.
Can a supply line be loose on a Cummins Engine?
This is also a good way to verify that the injector pump’s shut down solenoid is allowing fuel to the injector. If your supply fuel line is loose, it is possible to draw air into the fuel system at that point, so if you suspect you are not getting rid of the air in the system check your supply line connections.
What causes a plunger to get stuck on a Cummins Engine?
There is a small plunger that can break or get stuck. If you have poor supply pressure, you may have a bad lift pump, or possibly restricted or leaky supply lines. If you have never ran the engine before, or the injector pump has been worked on- check the return line banjo bolt (shown in the pictures below).
What should the lift pump pressure be on a Cummins Engine?
These engines should have between 7-15 psi of lift pump fuel pressure. We have banjo bolts available that allow you to connect a gauge to your fuel system. If you have fuel at the injector, good fuel supply pressure, and you are fairly certain you have no more air in the system, you may have a weak injector pump or incorrect injector pump timing.