Last Updated on 2 months by Ollie Barker
Wonder how to prime a Duramax? On GM truck models, the Duramax fuel filter is a standard diesel fuel filter as it can keep the sediments out of the fuel injectors. However, if your Duramax can’t start after changing the fuel filter, air might be in the fuel system. So how to prime a Duramax to let it start again?
In short, locate the plastic bleeder screw on the primer cylinder’s top. Crack the bleeder and release the air. Continue doing this until the fuel pours out and the car starts.
Where Is the Primer Located?
The housing for the fuel filter is on the engine’s passenger side, and it has a built-in fuel plunger for priming the gasoline system after the fuel filter has been changed.
The fuel filter housing can be accessed by removing the inner fender on the vehicle’s passenger side.
Keep in mind that since the Duramax diesel from 2001 to 2016 lacked an electric lift pump, you must use this plunger to bleed the fuel system of air after installing a new filter. Also, before starting the car, the fuel system should be bled air to prevent further wear and tear on the high-pressure injection pump.
For vehicles from the 2001 to 2010 model years, GM advises changing the fuel filter and draining the fuel water separator every 15,000 miles. For cars from the 2011 to 2016 model years, GM suggests doing so every 22,500 miles.
How to Prime A Duramax
Tools needed: a screwdriver or 13mm socket
As mentioned above, the motor’s fuel filter assembly is located on the passenger side. You can find a plastic bleeder screw and primer cylinder on top.
Crack the bleeder and release the air after pumping the cylinder until it becomes firm.
Continue until fuel comes out and the truck starts to run. Getting enough fuel up there may require a few cycles of starting up and turning off before it continues to run.
If priming takes more than a minute, your filter head needs to be rebuilt. As they age, the “O” rings lose their capacity to seal. You can buy only the “O” rings, or you can get a package for under $50 that has enough new gasoline lines to replace the two from the filter head.
- Remember to bleed the air out with the engine off.
- It is not a good idea to put raw fuel in the filter. Just keep pumping it. Your injectors may be damaged by raw fuel.
2 Ways to Prime a Diesel Engine
A diesel engine can be primed manually or by ignition:
It becomes vital to remove any air bubbles that have entered your fuel system when you change the fuel filter.
To ensure that fuel is circulating in your fuel system, you need to prime the fuel filter. Unfortunately, people frequently make the error of cranking the engine to prime the pump, which can wear down your battery and occasionally result in your gasoline not being properly recirculated.
Most modern diesel engines come equipped with a manual primer pump and an air-bleed screw that can be used to prime the pump and bleed the air.
You must crank this screw while pumping the priming handle (this may require 50–500 pumps) until the hissing sound of escaping air stops to use these manual functions. You can then tighten the screw and try to turn the engine after this happens.
Using Ignition to Prime
Simple steps like turning the ignition key to “run” for a few seconds, shutting it off, and repeating this process up to four times can prime the fuel pump in some diesel engines.
After a few minutes, you can restart the engine using this method, which your manufacturer most likely suggests. Crank the engine, and it should start after the fourth or fifth spin. Before shutting off the engine and checking the gasoline filter for leaks, ensure you let the engine run for 30 seconds.