Need Help - Fuel Leak - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**76sierraclassic** · 11-05-2004, 11:54 PM

Well, I have discovered that I have a somewhat substantial fuel leak back around my gas tank on my 76. I just crawled under the truck and it appears to be one, or possibly both, of the rubber lines that come from the sending unit in the tank somewhere before they hook up to the hard lines running up front.

I'm making the assumption that those hoses need to be replaced, but it doesn't look like that will be an easy task without dropping the gas tank. Is that correct? I can see where the hoses connect to the sending unit by looking between the bed and the cab, but I don't see away to get to them to replace them. If I do have to drop the tank to do this, I need to know how and what to watch out for (other than sparks of course). I've never done that before, and it's probably about 3/4 full or more.

Any tips or suggestions will be greatly appreciated.

Thanks,
Mike

cliffsta · 11-06-2004, 01:15 AM

I'm no expert, but maybe siphen the feul into a bucket or two to lighten the load?

rolson1039 · 11-07-2004, 09:54 AM

Assuming that the 76 is just like the 86 which ive done the tank on i found it easy enough to drop the tank using a large floor jack under it. There are several screws or bolts holding the tank filler to the bed side those come out, and theres a metal ground strap that needs to come off then you can take the eight bolts that hold the tank mounts and straps to the truck frame.
they are 9/16 head bolts once you get the tank down you have a ton of room to swap out the hoses. There are three different hoses sizes on there and i replaced my clamps too. You need a foot of each hose size on there. Using a foot of hose per size, there was a little extra on there which i was able to sort of loop so they didnt kink and make it difficult for fuel to flow.
You also have to make sure the fuel sender wires are properly hooked up too as those are what works your gas guage. the one wire you can reach from in between the cab and bed in a pinch but the black one needs to be done before you put the tank back.
hope this helps ya

blink32 · 11-07-2004, 10:08 AM

follow the above info, but I would use 2 jacks, 1 at either end, if you don't decide to siphon any gas out. And just make sure and unbolt the groundwire from the chassis for the sending unit, that will give you enough slack in everything to lower down the tank to access the other wire and hoses on top of the tank.

**76sierraclassic** · 11-07-2004, 11:03 AM

Thanks for the advice. I'll be giving this a shot tomorrow evening after work.

Mike

dark-star · 11-07-2004, 04:15 PM

6 or 8 bolts (varies) on the heavy bracket side next to the frame, yes make sure you loosen the ground wire to the tank and make sure you clean that area so you get a good ground when reinstalling or your gauge won't read, i use one floor jack and a long piece of 1" X 6" AND YOU'LL BE FINE, IT IS A LOT EASIER TO DRAIN THE TANK DOWN WITH THE OLD GAR(ooops) garden hose or you can just take the large hose off the fuel filler which by the way you need to loosen from the side of the truck or pop the hoses where they enter the tank or you will stay in the up posistion, it really is easy for any do it yourselfer, just take your time and above all do not smoke or use ignition sources when attempting this

while your at it, look at your tank really close as the seams leak over time and now would be the best time to go buy a new tank, most local radiator shops have them at a decent price. jw

11-05-2004, 11:54 PM	#1
76sierraclassic Senior Member Join Date: Feb 2004 Location: White Hall, AR Posts: 316	Need Help - Fuel Leak Well, I have discovered that I have a somewhat substantial fuel leak back around my gas tank on my 76. I just crawled under the truck and it appears to be one, or possibly both, of the rubber lines that come from the sending unit in the tank somewhere before they hook up to the hard lines running up front. I'm making the assumption that those hoses need to be replaced, but it doesn't look like that will be an easy task without dropping the gas tank. Is that correct? I can see where the hoses connect to the sending unit by looking between the bed and the cab, but I don't see away to get to them to replace them. If I do have to drop the tank to do this, I need to know how and what to watch out for (other than sparks of course). I've never done that before, and it's probably about 3/4 full or more. Any tips or suggestions will be greatly appreciated. Thanks, Mike

11-06-2004, 01:15 AM	#2
cliffsta Stepsides RULE Join Date: Jul 2004 Location: Pineville, LA Posts: 1,921	I'm no expert, but maybe siphen the feul into a bucket or two to lighten the load? __________________ 1981 Chevy C10 Custom Deluxe Stepside 350 V8, headers, side exhausts, 3-speed auto SOLD 1980 Chevy C10 Custum Deluxe Stepside 305 V8, Edelbrock Performer Intake, Edelbrock 1406 600CFM 4-barrel, TH350C. Bent rod. SOLD 1984 GMC Sierra Classic Longbed 6.2L Diesel SOLD 2009 Kawasaki KLX-250S too many mods for this signature 1999 Honda Accord EX 4-cylinder, 17" Motegi Wheels 215/45/17 Sumitomo tires, Tein S-Tech lowering springs, KYB GR2 shocks, Acura TL 20mm rear swaybar, debadged, blackhoused headlights, Short-Ram Intake Cardomain of the Accord

11-07-2004, 09:54 AM	#3
rolson1039 Registered User Join Date: Oct 2002 Location: NJ Posts: 404	Assuming that the 76 is just like the 86 which ive done the tank on i found it easy enough to drop the tank using a large floor jack under it. There are several screws or bolts holding the tank filler to the bed side those come out, and theres a metal ground strap that needs to come off then you can take the eight bolts that hold the tank mounts and straps to the truck frame. they are 9/16 head bolts once you get the tank down you have a ton of room to swap out the hoses. There are three different hoses sizes on there and i replaced my clamps too. You need a foot of each hose size on there. Using a foot of hose per size, there was a little extra on there which i was able to sort of loop so they didnt kink and make it difficult for fuel to flow. You also have to make sure the fuel sender wires are properly hooked up too as those are what works your gas guage. the one wire you can reach from in between the cab and bed in a pinch but the black one needs to be done before you put the tank back. hope this helps ya __________________ so many trucks so little time!!!

11-07-2004, 04:15 PM	#6
dark-star Registered User Join Date: Jun 2004 Location: fargo N.D. Posts: 80	have fun 6 or 8 bolts (varies) on the heavy bracket side next to the frame, yes make sure you loosen the ground wire to the tank and make sure you clean that area so you get a good ground when reinstalling or your gauge won't read, i use one floor jack and a long piece of 1" X 6" AND YOU'LL BE FINE, IT IS A LOT EASIER TO DRAIN THE TANK DOWN WITH THE OLD GAR(ooops) garden hose or you can just take the large hose off the fuel filler which by the way you need to loosen from the side of the truck or pop the hoses where they enter the tank or you will stay in the up posistion, it really is easy for any do it yourselfer, just take your time and above all do not smoke or use ignition sources when attempting this while your at it, look at your tank really close as the seams leak over time and now would be the best time to go buy a new tank, most local radiator shops have them at a decent price. jw

11-07-2004, 10:08 AM	#4
blink32 Registered User Join Date: Dec 2003 Location: OTR Posts: 338	follow the above info, but I would use 2 jacks, 1 at either end, if you don't decide to siphon any gas out. And just make sure and unbolt the groundwire from the chassis for the sending unit, that will give you enough slack in everything to lower down the tank to access the other wire and hoses on top of the tank.

11-07-2004, 11:03 AM	#5
76sierraclassic Senior Member Join Date: Feb 2004 Location: White Hall, AR Posts: 316	Thanks for the advice. I'll be giving this a shot tomorrow evening after work. Mike



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