Bubbles in a fuel pro 382. Detroit 60 series

Prior to this getting worse, I was seeing a lot of bubbles in the filter housing.The next day, I couldnt crank it up.I tried with ether and still couldnt.Called a mobile service and was able to get me going with ether.
I got back home and changed the suction line that comes from the fuel separator to the fuel pump, and I also chnaged out the fuel filter.I am not seeing bubbles , but I am wondering if I have solved my problem.After the change, I drove around for an hr.Shut it off and cranked it back up and I am not seeing fuel in the glass.I am wondering if this fuel will rise up a little bit for the system to remain primed.I guess I wouldnt know until I crank it up tomorrow.I seriously doubt its the check valve , because that check valve at least waits a couple of hrs and you usually dont see bubbles in the glass.My question is, incase I loose my prime from the Davco in the morning, how will I diagnose this in finding the air leak/bad hose on the suction line?If this truck cranks in the morning then I know that short suction line that I changed(that line did looked frail) was bad.Someone mentioned pressurizing the fuel line to find the bad hose.Any ideas on how to do this?

 

It cranked right up.
problem fixed!!!

 

Pour some fuel in the Davco bowl. When filter is new fuel is below filter almost, as it goes up the filter that means time to change when fuel is at top of filter. Make sure to change your o rings. I'm guessing you had air getting in before you changes thing.

 

Yep, I just learned all this.Yes, I had a major bubble before all these changes.The suction line or the dome must have fixed the problem.Suction line, pressure line, fuel pressure in PSI, crossover T fitting,return lines and check valve...............................I learned a lot from this experience.The only thing I need to learn is how to pressurize the system to detect a bad suction line

 

You can pressurize the system through went tube on one of the tank

 

What I’ve done on my KW is remove one of the vent tubes on top of the fuel tank and screw in an air line fitting. Then on the other tank, remove the vent tube and screw in a plug so air can’t escape. Now attach an air hose WITH A REGULATOR to the fitting on the first tank. You want to regulate down to just a few PSI. Seems like we use 15 PSI when we do this in the shop. DO NOT hit it with 120 PSI.

Now turn the key on to open the fuel shutoff solenoid but don’t start the truck. Now apply your 15 PSI of air and search for leaks. May take a while but a bad hose or fitting should begin to drip.

 

Sorry, guys this problem has not been fixed as I thought.I noticed this 2 days after my last posting.I left it with the mechanic.It's still loosing it's prime in the Davco.Took it to the mech and he plugged his pro link.Injectors are fine from the scanner.From research, I was thinking vent tube but another mechanic said it shouldn't cause it to loose prime and not start.Mech. will update me in a couple of days.Not sure, it may even be injector O ring as another mech suggested.I have changed all the fuel lines except 2 suction lines on the seconday.I didnt see that much leak from those hoses.My mech. will keep me updated.

 

Is your davco empty in the morning???

How do you come to the conclusion you loose your prime in the davco??

 

Yes, , my davco is empty in the morning.Hard to also start.I dont even know why one mech said check valve.I have never seen a check valve act up while idling.All my symptoms and what I have done is in this thread.............................hard to start in the morning, sometimes starving for fuel while idling but drives normal on the hwy

 

Your davco has a white plastic check ball inside the unit on the side closest to your fuel tanks. Replace it. Or at least make sure it has no junk in it .

Your davco should never be empty in the morning. Only way that is possible is if that check valve is not functioning