I just changed the secondary fuel filter (under the hood) Went to start the engine to purge the air before changing the primary filter (on the frame rail). I usually turn the key on until the pump stops then crank on 5-8 sec intervals until it starts. Ususally takes three to four cranks for the secondary filter. So far I have run the batteries down and only got it to fire a couple times for about 5 seconds so somehow there is air in the system which is not purging this time. I took the filter cap off and made sure the filter was fitted properly and at that time the fuel bowl was full. Any suggestions?

 

change top filter then frame filter THEN turn key to on position and count to 30 then turn key off- repeat this 6 times then turn key to start. this is the only way to puirge the air. check owners manual supplement for exact directions....

 

At this time I would suggest that you check the fuel cutoff switch to see if it tripped.

Depress it just to make sure and then try again.

 

Attempting to start the engine *does not* purge air from the fuel system, it introduces air to the HPFP which can damage it.

The purge method specified in the owner's manual is to cycle the key *without starting* the engine, which causes the fuel pump to run and push fuel through the system which causes the air in the system to be pushed back to the fuel tank via the fuel return line.

If you've pushed air further into the fuel system, it may require purging from either the low of high pressure sides of the system with the appropriate tools.

 

I agree with wp6529, best to not crank the engine until the system is purged. Also the procedure is to change both filters at once and then purge. If you purge the secondary filter and then replace the primary, you're still going to have to work the air through the primary and then the secondary before starting the engine.

 

I've found that following the owner's manual isn't enough to get the air out before cranking. On two occasions I've followed the book to purge the air then cranked the truck and had the truck stumble and die and be a pain to restart.

I now cycle the key for a few minutes. If you listen closely you can actually hear the air going back to the tank and tell when it is all out.

 

Did mine today, exactly as stated in the instructions in the diesel supplement manual. Drained the water separator, changed the frame rail filter, changed the filter on the top of the motor, cycled the key 6 times for 30 seconds at a time and it started right up like a champ...

 

I have always drained changed bottom filter first, run truck for a time ,than changed top. I feel this will not let air in system. Also any thing getting past bottom filter will be trapped in top, than installing new top filter will start clean.

 

Changing one filter at a time makes for a sloppy mess in the engine compartment too. Change and purge following instructions in the manual. You'll be a whole lot happier.