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Topic: Bleeding air from generator fuel system (Read 431 times) previous topic - next topic

Bleeding air from generator fuel system

Good morning everyone
I have a Powertech 10K generator and would like to know how to properly bleed the fuel line.
In the manual (picture) it shows the procedure for "gravity fed tanks" but does not mention the ones with fuel pumps.
I have been changing the fuel filter and filling the new one with diesel but I know there is still some air.
I think the bleed screw is located just to the left of the speed control lever. It doesn't look like it's been used to much since there is no paint missing.
Once I am ready to bleed the air and have the vent plug opened, do I literally turn the engine on or is there a way to operate the fuel pump without running the engine?

Thanks
Frank
Frank & Daisy
NO LONGER  "looking for the perfect Foretravel
36' or less non slide preferred."  She has been found and is ours.
2003 U320 36' non slide  Unit 6103
Cummins ISM 450
Allison 4000MH

Re: Bleeding air from generator fuel system

Reply #1 –
Try and start the engine with the bleed valve closed,if it starts and runs ok you do not need to bleed the "air"it would have passed thru the system.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: Bleeding air from generator fuel system

Reply #2 –
When I changed my filters I just started it,it ran for a few seconds and died. I restarted it and it ran fine from there. I changed some fuel line this week from the pump to the filter and filter to engine, fuel drained out as I was doing it but it started right up. May check you fuel line, on mine between the fuel pump and filter the hose was up against the motor Rubbing. Probably been that way since new. It had been rubbing so long it had rubbed thru the wire loom covering the hose and hose causing a small leak in the hose....


Keith
The selected media item is not currently available.Keith & Jo
2003 U320T 4025 PBBS Designer series
Build 6203    Cummins 500hp
2000 U320 4010 WTFE / Build 5762 —Sold—
Motorcade #18070   
Pasadena, Texas
2015 Jeep Wrangler Sahara-Sunset Orange pearl coat
Don't argue with a fool, people watching might not be able to tell the difference.

Re: Bleeding air from generator fuel system

Reply #3 –
Quote from: Lt403 –
Good morning everyone
I have a Powertech 10K generator and would like to know how to properly bleed the fuel line.
In the manual (picture) it shows the procedure for "gravity fed tanks" but does not mention the ones with fuel pumps.
I have been changing the fuel filter and filling the new one with diesel but I know there is still some air.
I think the bleed screw is located just to the left of the speed control lever. It doesn't look like it's been used to much since there is no paint missing.
Once I am ready to bleed the air and have the vent plug opened, do I literally turn the engine on or is there a way to operate the fuel pump without running the engine?

Thanks
Frank
With the generator in the glow position, the electric fuel pump should run and enable you to bleed the air out.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Bleeding air from generator fuel system

Reply #4 –
When I recently changed my fuel lines the genset just started without any bleeding necessary.

Re: Bleeding air from generator fuel system

Reply #5 –
I have a fuel water separator before my fuel filter and when I drained it some the other day the generator was not happy when I restarted it. It shut down and when I restarted it it "coughed" for a while before running smoothly.
Doesn't that hurt the engine?
Frank & Daisy
NO LONGER  "looking for the perfect Foretravel
36' or less non slide preferred."  She has been found and is ours.
2003 U320 36' non slide  Unit 6103
Cummins ISM 450
Allison 4000MH

Re: Bleeding air from generator fuel system

Reply #6 –
As several others have said, the approximately 9 seconds that the fuel pump runs prior to the starter kicking in is enough time to push any air past the injectors.  Worst case, it dies and you initiate a second start cycle and it almost always runs then. 

Before I replaced my fuel lines I had an air leak that necessitated me thoroughly bleeding the system each time I started the generator.  To bleed the system I ran a 12 volt line to the fuel pump so I could run it without initiating the start sequence.  The first time or two I simply loosened the banjo bolt on the fuel return line at the last injector as I learned in the "old school".  Once all the bubbles quit coming out and you have clear fuel running out, you tighten the bolt and you are ready to run.  Of course this makes a real mess.  It didn't take me long to realize that rather than loosening the banjo bolt and having the air/fuel spill out all over everything, I could just run the fuel pump for several minutes with the system closed.  That way the air/fuel would just flow back to the fuel tank, no muss no fuss.  Of course there is no way to actually see when all the air is purged but several minutes always cleared it and no fuel wasted. 
Jan & Richard Witt
1999 U-320  36ft WTFE
Build Number: 5478 Motorcade: 16599
2011 Jeep Wrangler Unlimited w/Air Force One
Jan: NO5U, Richard:KA5RIW
The selected media item is not currently available.

Re: Bleeding air from generator fuel system

Reply #7 –
It doesn't hurt anything, if it gets too much air it will stop and need to be bled. On my Isuzu you have to crack the fuel lines at the injectors to get things smoothed out.
Bruce, Linda, and Macy
Zoey RIP 1/20/19
1999 U295 40' build #5400
2017 silver Jeep Wrangler, 1260 watts of solar on top
Moving around the country
 

Re: Bleeding air from generator fuel system

Reply #8 –
Quote from: Jan & Richard –
As several others have said, the approximately 9 seconds that the fuel pump runs prior to the starter kicking in is enough time to push any air past the injectors.  Worst case, it dies and you initiate a second start cycle and it almost always runs then. 

Before I replaced my fuel lines I had an air leak that necessitated me thoroughly bleeding the system each time I started the generator.  To bleed the system I ran a 12 volt line to the fuel pump so I could run it without initiating the start sequence.  The first time or two I simply loosened the banjo bolt on the fuel return line at the last injector as I learned in the "old school".  Once all the bubbles quit coming out and you have clear fuel running out, you tighten the bolt and you are ready to run.  Of course this makes a real mess.  It didn't take me long to realize that rather than loosening the banjo bolt and having the air/fuel spill out all over everything, I could just run the fuel pump for several minutes with the system closed.  That way the air/fuel would just flow back to the fuel tank, no muss no fuss.  Of course there is no way to actually see when all the air is purged but several minutes always cleared it and no fuel wasted. 
With the closed system, the electric pump may not generate enough pressure to unseat the fuel return valve and allow fuel and the unwanted air to head back to the tank. In the attached photo, the valve is shown. Some owners have said that the generator would only run smoothly with the valve partially open. This is because the generator feed line has cracks and is allowing air into the system.

If the generator is running well and just shut off to change filters, opening the valve with the glow plugs activated will allow the electric fuel pump to purge the air so when the valve is closed, the generator will start immediately. If the engine has shut down because of air in the system, an injector line may need to be cracked a quarter turn at the injector and the engine cranked. I usually let the engine run with one cracked until it runs half way smoothly and then tighten the pipe (while running).

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)