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Topic: Fuel continues to run out of line from main tank (Read 665 times) previous topic - next topic

Fuel continues to run out of line from main tank

Disconnected the generator fuel line that runs from the Racor Water Separator filter to the main tank in order to connect a union thereby bypassing the water separator filter.  I took an involuntary Diesel shower while the separated line from the main tank kept running and running a strong steady stream of fuel.  What causes this?  I don't recall ever having this problem; specifically when replacing the water separator filter.

What a mess it made while I tried to connect the union to the 2 lines.  Repeated the same mess when I disconnected the union to reconnect the fuel filter.
Fiddler
1959 Parris Island grad
40' 2001 U320 Build 5875
1999 Suburban K1500 toad
1986 Corvette Pacecar
ssoftail@comcast.net

Re: Fuel continues to run out of line from main tank

Reply #1
Sounds like a syphon. If the point of disconnection was lower than the fuel level in the tank and the line was filled with fuel, as soon as the line is disconnected it's like a hole in the side of the fuel tank.
J D Stevens
1997 U295 CAI 36' Build #5085
2002 Subaru Outback
Motorcade 16869
Bellville, TX

Re: Fuel continues to run out of line from main tank

Reply #2
Fiddler, Sorry to hear about the shower. I believe that you created a siphon , the line end is most likely lower than the dip tube in the tank.
Did the genny run with the filter bypassed ?
Gary B

Re: Fuel continues to run out of line from main tank

Reply #3

Bypassing the water separator filter did not solve the problem.  I've got 2 more lines to replace;

1- line connecting the fitting at the back of the generator housing to the water separator flter.  Note the other side of the fitting connects the line (just replaced) going to the fuel pump. 

2-  line going from the water separator filter to the main tank....not looking forward to this one; I can't get it to budge to see which fitting it attaches at the top of the main tank.

BTW, How do I break the siphon to avoid another shower?
Fiddler
1959 Parris Island grad
40' 2001 U320 Build 5875
1999 Suburban K1500 toad
1986 Corvette Pacecar
ssoftail@comcast.net

Re: Fuel continues to run out of line from main tank

Reply #4
Pinch the hose with pliers before disconnecting the fuel hose.
 Richard B.
Richard & Betty Bark & Keiko our Golden Doodle
2003 U320T 3820 PBDS
Build # 6215
MC # 16926
2016 Chevrolet Colorado 4X4 diesel

Re: Fuel continues to run out of line from main tank

Reply #5
Use vice grip pliers
Richard & Betty Bark & Keiko our Golden Doodle
2003 U320T 3820 PBDS
Build # 6215
MC # 16926
2016 Chevrolet Colorado 4X4 diesel

Re: Fuel continues to run out of line from main tank

Reply #6
Check Barry Beam's wed site,he has the diagram of the fuel tank layout.
The selected media item is not currently available.Bill&Doris 97 U270 36'
University of Parris Island Class of 66
Semper Fi  Build# 5174 MC#17094

Re: Fuel continues to run out of line from main tank

Reply #7
Sincere thx to all; great forum and great people on this site.    Checked Barry's documents on replacing generator fuel lines and it it proved to be an excellent reference.  Also, many thx for suggesting the lock pliers to pinch off the running fuel line;  the obvious is sometimes not so obvious when you've had too many birthdays I guess.  Looks like I've got some serious generator line replacement work ahead.
Fiddler
1959 Parris Island grad
40' 2001 U320 Build 5875
1999 Suburban K1500 toad
1986 Corvette Pacecar
ssoftail@comcast.net

 

Re: Fuel continues to run out of line from main tank

Reply #8
Looks like I've got some serious generator line replacement work ahead.
If your generator fuel lines need replacement, consider replacing the lines to the "big" engine, also. When our genny quit operating reliably, fuel lines were the problem. Turned out the big lines were cracking, also, and it was only going to be a short while before we would be stranded. To properly replace the generator lines, the fuel tank had to be pulled out. It made sense to replace ALL the lines and the fittings on top of the fuel tank while it was out.

Another way to avoid the siphon is to make sure the hose end that you disconnect is higher than the level of fuel in the tank. Seems to me that pinching a line might damage it. Downside of working with little fuel in the tank is that priming the line can be tough. FOT had a difficult time getting my "big" engine to start after replacing fuel lines. Fuel level in the tank was way low and it was probably uphill all the way to the engine. There was lots of cranking, pumping the priming pump, pressurizing the fuel tank, and opening an injector line to allow air to escape.
J D Stevens
1997 U295 CAI 36' Build #5085
2002 Subaru Outback
Motorcade 16869
Bellville, TX