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Diesel fuel lines/ How Long & What size

August 14, 2010, 10:14:15 pm

I am having to replace my fuel lines for the generator on the '96 U-320. How large and how long are the lines. Is it necessary to put high pressure lines on both the in coming lines and the return line. I was under the impression it only needs to be on the feed lines. I also want to know how large the size is. I've heard conflict in sizes. Thanks, in advance, for the help. 

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Re: Diesel fuel lines/ How Long & What size

Reply #1 – August 15, 2010, 09:51:58 am

I did that not too long ago, but I have already forgotten how long the hoses were, maybe I can find it later.  I don't think pressure matters very much on these lines as one is under suction and the other just taking fuel back to the tank.  What would be important is the hoses resistance to collapse when making sharp bends.  I replaced mine with the same hose FT used although it was rather expensive.  FT used a high quality hose that I think they thought would have a long life and be resistant to collapse, although it does have a high pressure rating. I think I bought 32 ft, but it was just enough.  The length could also depend on whether the fuel tank is at the back of the compartment or the front.  Mine was at the back.

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Re: Diesel fuel lines/ How Long & What size

Reply #2 – August 15, 2010, 12:48:32 pm

Gervin, I used normal NAPA Fuel hose as I could not find the stuff FT used, I think it was less than 15 feet on a GV, it solved the intermittent shut off problem and its been over a year since I did it in CO.
My best memory is that it was 5/8 hose.

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Re: Diesel fuel lines/ How Long & What size

Reply #3 – August 15, 2010, 03:29:26 pm

Just got back from the MH and found that the generator fuel hose is Aeroquip as installed by FT.  Couldn't see the number with out going under the vehicle, so I don't have that, nor could I find a bill with the length of hose I bought.  It is what aeroquip calls Socketless hose.  They make special barbed fittings and you just push the hose on the fitting and that's it, doesn't need a hose clamp.  However to remove it the hose must be slit at the fitting, so you lose about an inch of hose.  One must also be very careful not to nick the fitting when slitting the hose.  FT used them on the tank, but not on the generator.  I ordered a couple of fittings for the generator and installed them.  Later realized that this was not too smart if I ever have to remove the generator.  I think if I was doing this again, I would just use an ordinary fuel hose as I spent about $110 just for the hose and fittings.  The hose was about $3.35 a foot as the 2 fittings didn't cost much.  That was the lowest price I could find on the internet.

On my FT the pickup is at the center of the tank, difficult to get to.  The return is near the end of the tank.  There are some pictures in the photo/files of how I got in the compartment to get to the center tank fitting.  Look for a picture with my feet sticking out of the compartment.

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Re: Diesel fuel lines/ How Long & What size

Reply #4 – August 16, 2010, 03:08:27 pm

I replaced the generator fuel lines on my 1996 U320 in May. I used forty feet of standard 3/8 fuel line from Kragens and 3 feet of 5/16 fuel line and hose clamps. The OEM line was covered in a nylon braid but that did not stop the cracking on outside of bends. There are two 20 foot lenghts of 3/8inch between the tank and the generator (feed and return) The 3 feet of 5/16 was used on the generator itself. It would be possible to use only 36 feet of 3/8 line, but I wanted some slack available. The feed line was in the center/top of the fuel tank and new hose went to it with a hose clamp. The return was at the top on the driver's side of the tank and impossible to reach without removing the battery side bulkhead. I installed a coupling and left three feet of the old hose attached to the tank.

Wyatt

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