Air Headache

[84ord]

I Changed my IP and am having a reall nasty time getting the air out before the pump. I was told to bypass the secondary fuel filter so I did but still have problems. Any tips?

 

[tonkadoctor]

Pressurize the fuel tank (that your valve is set to pick up from) with low pressure air, 10 - 20 psi is usually plenty.

Use a air nozzle/blow gun on an air hose by holding it in the filler neck and seal it with a shop rag. The pressure will force fuel through the pickup pick up tubes and lines to the pump.

It works best if you have a helper that can bleed and retighten the lines once fuel gets to the pump and then crank it over.

It's an old school trick that works well on semi trucks.

 

[84ord]

What would be the cause of loosing your prime? I seems like whenever I get all the air out wait awhile theres more again

 

[Diesel JD]

Many possibilities. Rememeber its just like you ran that pump out of fuel when you install a new one. Follow this procedure: first make sure you are getting fuel to the back of the injector pump when you are cranking with the stock pump or at all times with the key on if you have an electric. After you have verified that you do, tighten this line, crack the lines at the injector pump on the front of it. Crank it over for 10 seconds 2 or 3 times and give it a respectable 2-3 minute cooldown. Tighten down the lines at the front of the pump after you see some fuel squirting from them or after about 3 cycles of this type of cranking. Afterwards, crank with the lines loose, leave them all loose until you see fuel dripping or bubbling/squirting from 3 or more lines, then tighten them all down, cycle the glow plugs twice and put your foot to the floor. Feather the throttle to keep it going until the idle smoothes out. If this doesn't work, do what Tonka says and pressurize the tank, but keep it to the 10-20 PSI he suggested, anything more might crack that old tank. Additionally, are you sure that you have at least 1/4 tank in both tanks? Clean dry fuel? It might help not to deplete the batts if you have a charger connected while bleeding, juts be careful for the connections if you do that,
J.D.

 

[Diesel JD]

As to losing prime this can come from any air/fuel leak in the supply lines or return system, teh leak off ts, a weak or defective lift pump diaphragm and probably some other things I'm forgetting.

 

[Full Monte]

If you'd put the particulars of your truck in your signature, it would help us figure out what model we're working on.

Do you have the old water separator on the firewall on the driver's side? It's famous for allowing air into the system. You can bypass it and lose that problem.