Author Topic: Fuel Hoses on Sending Unit  (Read 4442 times)

Offline jetmech

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Fuel Hoses on Sending Unit
« on: July 08, 2018, 11:58:09 PM »
I have an 86 Suburban that I am replacing the sending unit. Not enough room to put the hoses onto the sending unit. I can get the filler hose and vent hose but the three smaller hoses seem impossible to connect and clamp. I used the old hoses to make new ones same length. Do I have to make them longer so I can let the tank be lower in order to make the connection? Pretty sure the body was not on when they were connected at the factory. There must be a way to do this without lifting the body.
'86 Sub and '86 SWB C-10
1990 454 SS

Offline Irish_Alley

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Re: Fuel Hoses on Sending Unit
« Reply #1 on: July 09, 2018, 07:02:12 AM »
On my crew cab I attached one of the far gas tank bracket by one bolt this let it tilt. I then cut the length of hose and reattach everything back together. This is 100% wrong cause the hoses are too long and will kink. Don't do it that way. Lucky I have dual tanks, been meaning to drop the tank and redo the setup but just haven't found free time yet. I kinda want to know how others did it also
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Offline ehjorten

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Re: Fuel Hoses on Sending Unit
« Reply #2 on: July 09, 2018, 08:53:05 AM »
On the saddle tanks I have always just lowered them cautiously as much as the hoses would allow.  Usually balanced on a couple of jacks with a large board spanning between them.  Then you have to sort of get your arms and head in-between the body and tank and reach up in there and disconnect everything.  Usually the old hoses will be difficult to get off and you will have to cut them off.  It is probably a good idea to replace the old rubber hoses anyway.  Don't forget to disconnect the ground strap from the sending unit to the top flange of the rail and also disconnect the 2-pin Weatherpack connector.  Installation is the reverse.

On the issue of hose length...I have always just made up new hoses that are the same length and installed.  I have only ever had an issue with the driver's side tank.  The original hoses are shaped like a bell and new hoses, especially if you are fuel injected and using the stiffer FI hose, then they won't like to bend that way and can kink.  What I did on my crew cab was to make the hoses longer and make them go in a loop, but I am not familiar with the Suburban fuel tank installation.
-Erik-
1991 V3500 - Gen V TBI 454, 4L80E, NP205, 14 bolt FF, D60, 8" Lift on 35s
1977 K20 Silverado - 350, THM350, NP203, 14 bolt FF, D44, Stock Lift on 31s
1969 Chevelle Malibu Sport Coupe - EFI350, THM350
1968 Chevrolet Step-side Pickup - 300HP L6

Offline jetmech

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Re: Fuel Hoses on Sending Unit
« Reply #3 on: July 10, 2018, 12:12:36 PM »
The Suburban has a big square tank that fits tight between the frame rails with the fuel lines right in the center. A cross member front and back make it very difficult to reach the sending unit much less trying to attach lines and clamps. I think I am going to have to make the hoses longer and hope they will tuck in and not kink or raise the body a few inches. I like the idea of making them long enough to make a loop. This would give me plenty of room to get the job done.
'86 Sub and '86 SWB C-10
1990 454 SS

Offline blazer74

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Re: Fuel Hoses on Sending Unit
« Reply #4 on: July 10, 2018, 08:24:20 PM »
Try going in from the side?

Offline jetmech

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Re: Fuel Hoses on Sending Unit
« Reply #5 on: July 11, 2018, 12:10:07 AM »
In order to go below the frame rails and above the tank then the tank has to be tilted so much the hoses won't reach. Not enough room to reach in above the frame. I can reach in but not enough to get the hoses on. I am to the point of using longer hoses and hope for the best. Very frustrating and I know someone has run into this problem before. May be some old mechanic at the local dealership has done this.
'86 Sub and '86 SWB C-10
1990 454 SS

Offline bluevan

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Re: Fuel Hoses on Sending Unit
« Reply #6 on: July 11, 2018, 08:48:31 AM »
I don't have any suggestions, but I recently carved the floor out of an 89 k5 to get at the tank.  Here are some pictures that could possibly be used for reference so you can see what you are dealing with?  I imagine that subs are pretty much the same setup.
- Joel
1982 GMC K10 (work in progress)
1989 Chevy G20 Van
1994 Chevy Impala SS
1974 Landcruiser (Chevy powered)

Offline jetmech

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Re: Fuel Hoses on Sending Unit
« Reply #7 on: July 12, 2018, 12:09:58 AM »
Pretty much the same thing. My hoses are rubber and only about 8 inches long from the sending unit to the hard lines. By the way I found the filler hose and vent hose at O'rielly's if you need to get those. 1 3/4 filler and 5/8 vent on my '86.
'86 Sub and '86 SWB C-10
1990 454 SS

Offline blazer74

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Re: Fuel Hoses on Sending Unit
« Reply #8 on: July 12, 2018, 02:49:24 AM »
It is doable. Replaced all my sender hoses several years ago with the tank installed on a K5.

Also just removed the tank recently and was able to disconnect.

I’m 6’ and 195.

I don’t know how much different the Sub is but you may need to find someone that can reach in there.

Offline VileZambonie

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Re: Fuel Hoses on Sending Unit
« Reply #9 on: July 12, 2018, 05:37:25 AM »
I just replaced the fuel pump in my Suburban a few weeks ago and because my lift was tied up I did it in the driveway. You can absolutely reach the lines on top of the tank when you start to lower it down. As suggested, replace the hoses and get new (good) clamps. No need to make the hoses longer as they will kink when you put the tank back up.
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Offline jetmech

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Re: Fuel Hoses on Sending Unit
« Reply #10 on: July 19, 2018, 01:28:23 AM »
Thanks all, I got the lines in and it is running again. I loosened the hard lines along the frame and they moved over a few inches. That allowed me to tilt the tank down on one side enough to slide the lines on and then get clamps on them.
'86 Sub and '86 SWB C-10
1990 454 SS