How can I bleed air from fuel line?

See


http://manuals.deere.com/omview/OMRE73927_19/?tM=HO


. Fuel tank must be full of fuel with the fuel shut-off valve open.
X9811
AG,OUO1043,272 -19-20OCT03-1/2

IMPORTANT: To avoid injection pump damage, DO NOT attempt to start the engine while bleeding the fuel system.

2. Loosen fuel return line (A). Loosen filter base bleed screw (D). Push priming pump (C) until fuel runs out smoothly without spitting, then tighten bleed screw (D).

3. Loosen injection pump bleed screw (B). Push priming pump (C) until fuel runs out smoothly without spitting, then tighten fuel return line (A) and bleed screw (B).

If you press and continue to press the primer bulb in the fuel line will it continue to run ? Will it run with the choke on ? Possible causes. Air entering the fuel line at the tiny o ring on the fuel connector, does the primer bulb in the fuel line go hard when pumped ?

Either loosing fuel pressure or most likely still has air in the system. Air in the lines and filters can cause a lot of frustration. Bleed all you can from the lines and then do the injectors last. I pressurize the tank with very low air pressure to bleed the system. Use a small air compressor on the fuel tank vent line with the fitting the line came off of plugged to make a little pressure on the tank, turning the pump off as you are in procedure so not to make too much pressure and bleed the filter fitting then the connection at injector pump then the injectors in order as you come to them from said pump. Once done, take the cap off the fuel tank and let the pressure off and re-hook the vent line to tank fill neck. Now that all air is out, it will start and run continuously. Air is evil to diesel systems.

we dont have this engine here, USA.
but i have the WG jeep book,
starting page 12 , chapter 14


FUEL INJECTION PUMP BLEEDING
(1) If the fuel injection pump has been replaced,
air should be bled at the overflow valve before
attempting to start engine.
(a) Loosen the overflow valve (Fig. 18) at the
rear of the injection pump.
(b) Place a towel below the valve.
WARNING: WHEN CRANKING THE ENGINE TO
BLEED AIR FROM THE INJECTION PUMP, THE
ENGINE MAY START. PLACE THE TRANSMISSION
IN NEUTRAL OR PARK AND SET PARKING BRAKE
BEFORE ENGAGING THE STARTER MOTOR.
CAUTION: Do not engage the starter motor for
more than 30 seconds at a time. Allow 2 minutes
between cranking intervals.
(2) Crank the engine for 30 seconds at a time to
allow air trapped in the injection pump to vent out
the fuel injector drain tubes. Continue this procedure
until the engine starts. Observe the previous WARNING
and CAUTION.
(3) Tighten overflow valve.
HIGH-PRESSURE FUEL LINE BLEEDING
WARNING: THE INJECTION PUMP SUPPLIES HIGH-
-PRESSURE FUEL OF APPROXIMATELY 45,000 KPA
(6,526 PSI) TO EACH INDIVIDUAL INJECTOR
THROUGH THE HIGH-PRESSURE LINES. FUEL
UNDER THIS AMOUNT OF PRESSURE CAN PENETRATE
THE SKIN AND CAUSE PERSONAL INJURY.
WEAR SAFETY GOGGLES AND ADEQUATE PROTECTIVE
CLOTHING AND AVOID CONTACT WITH
FUEL SPRAY WHEN BLEEDING HIGH-PRESSURE
FUEL LINES.
WARNING: DO NOT BLEED AIR FROM THE FUEL
SYSTEM OF A HOT ENGINE. DO NOT ALLOW FUEL
TO SPRAY ONTO THE EXHAUST MANIFOLD WHEN
BLEEDING AIR FROM THE FUEL SYSTEM.
Bleed air from one injector at time.
(1) Loosen the high-pressure fuel line fitting at
the injector (Fig. 19).
(2) Crank the engine until all air has been bled
from the line. Do not operate the starter motor
for longer than 30 seconds. Wait 2 minutes
between cranking intervals.
(3) Start the engine and bleed one injector at a
time until the engine runs smoothly.

end quote.
pump timing is on next page
or tank filter line priming before. above.

That's the flow chart I use working on Tanks. (M60 chassis, not Abrams M1A2)

Make sure the filter for fuel is clean, and there is no water. Make sure pickup tube/device to fuel pump is not restricted, and there are no cracks in tubing, etc, that can cause cavitation. (Air instead of fuel is being drawn in) In other words make sure the fuel pump is getting fuel.

Fuel pump line removed from fuel injector pump, run the pump, fill a clean jar. Measure amount based on time. How long to fill, how much.

(Look at your watch second hand. It is so much fuel per minute. Amount is what we're looking for here. Fuel Injector takes care of the pressure. You just want to see if the fuel pump is drawing fuel, and delivering it to the fuel injector pump )

Fuel pressure from fuel pump, could be bleeding down. Valves in fuel pump are no good. If fuel pump is not re-buildable, fuel pump is no good.

After fuel pump line is re-attached back to the injector pump, it is attached loosely. A half turn loose, or so. This is so you can bleed the air out. Allow the fuel pump to run for a few seconds, or a minute, and bleed the air out here. OR, you will be cracking each injector line loose, and bleeding air out. (No fun)

You can 'crack' an injector line loose, and check it's pressure. It is HIGH pressure now, so be forewarned. Use safety measures, and at least use a pair of safety glasses, and have a fire extinguisher CLOSE.

Shouldn't be any fires if no flames, or sparks are not present, but ALWAYS be prepared for the worse.
(Cigarette dropped in Diesel won't set it on fire. Spark near the fumes WILL)

I have seen a pickup sump line break, and drop the pickup sump for the fuel pump, down in the fuel tank. No fuel can be drawn by the fuel pump. Your fuel pump may be submerged in the fuel tank. Just offering hands on experience.
I have seen a lot of 'weird' things concerning military vehicles, and diesel engines. lol!

There is also a fuel pump (Diesel) pressure gauge you may be able to rent. Meter the fuel pressure from the fuel pump.

Fuel pump checks out the problem is the fuel injector pump, just as you have surmised.
Many have rebuild kits. They are no fun to rebuild. However cost of rebuild kit, is probably not much more than cost of rebuilt injector pump.

The military has equipment like the ditch witch. Civilian contractors use a Ditch Witch also. I do not work on them. Close as I get is a 1K Forklift. (Then 4k Forklifts, 10K, and 20K, plus all the wheeled vehicles, and track vehicles, Up To the Abrams, but Not Abrams)

Don't know if I have done any good. You seem to have your 'eye on the ball'.

Regards,
joecoolvette

[When you get everything back together, bleed the air out. Crack the fuel pump to fuel injector pump line, first. Air bled out here, then crack each injector line, ONE AT A TIME, and bleed the air out.
We 'cheat' sometimes. We have a fuel cap with an air valve mounted in it. Car tire air valve. Air is pressurized in fuel tank, of around 20 lbs, (Usually a 'guess-timate'), and forces air through the fuel system, and out. Takes a while, but I usually don't have to crack any lines to bleed air out.

Regards,
joecoolvette

This is not unusual on a diesel. What happens is there is air in the system. If this vehicle has an electric fuel pump loosen line where fuel enters injection pump then turn ignition key to the on position and watch for fuel to appear and then quickly tighten line before turning off key. Then try to start. If does not have electric fuel pump will need a second person. One will loosen line and watch while other cranks vehicle until you get fuel and tighten line before the other person releases ignition switch unless vehicle starts first. If that doesn't do the job do this where line hooks onto each injector. Probably will not have to do this to all injectors but could run rough until all the air gets out of everything. I have farmed with diesel tractor for 25 years and dad I drove the gm vehicles with the 5.7. You normally don't start a diesel without bleeding the air out of the lines although some will self bleed most won't. Hope this does the trick.

Possible that there is an AIR LOCK and so you will need to bleed off the air within for the fuel to flow into the pump. So remove the fuel line and allow fuel to flow or blow into the fuel tank.( must **** out the fuel )
once the fuel comes over the pump will hold on.
Next time make sure that the tank does not run dry.

This is NOT good! You can try bleeding the fuel system first. More than likely, air is trapped in the fuel lines, injector, and injector lines. Bleed at the fuel pump, (On the fuel pump to injector pump side), then the injector pump, then each line.

(You have to loosen the fitting to each line to each part, then when the air is bled out, and fuel comes through steadily, close it)

I also suggest an attorney to resolve the problem, as there may be damage. Pistons could have holes in them. Do a compression check.

Usually diesel's have 16:1 ratio compression. Today's gasoline engines have anywhere from 8:1, to 8.5:1, to maybe 9.0:1, (Maybe)

I'm willing to bet though, that you just have air in the system, and it needs to be fully bled out.
There is NO half stepping on this!
You have to start at the source, loosen each fitting, bleed the air out, and continue on down the line.