Fuel tank replacement

[Customdeluxe81]

Hi guys, my 1981 c10 long bed’s fuel tank is leaking and I’ve got all the parts to replace the tank but I have a couple questions. So if I look between the back of the cab and the front of the bed I can see there is two short rubber fuel lines, one fuel and one vapor, that go over the frame rail. Has any one replaced their tank and how did you deal with disconnecting and replacing these lines. It looks like they are impossible to get too with the bed still on. Any and all help/advice is welcome. As well as pix on how it’s done are welcome!
Thanks
Bill

[VileZambonie]

Typically you have a 3/8", 5/16" & 1/4" hose clamped on both ends. Now is the time to replace them. Once you begin to lower the tank, you can access the hoses. Make sure you don't kink them when reinstalling.

[Customdeluxe81]

So you mean the short metal lines that run from the tank to the passenger side frame rail? I was thinking they may be the key, I was going to remove them from the frame and see if that helped out. And I’m going to replace all the rubber hoses while I’m there.

[VileZambonie]

No, I am referring to the hoses (rubber) at the tank sending unit.

[Shifty]

It's easier to take out the bed bolts and tilt the bed back...you can get to everything with far less effort.

[Customdeluxe81]

The rubber hoses at the tank are less then 12” long, (more like 6/7” long) I don’t know how much they will get me being 40 years old they are most likely hard and brittle and not going to provide much in the way of movement.

Shifty; I had thought about taking the bed off to gain access, but thought that was a lot of trouble to change a fuel tank...

I’m going to start replacing the main fuel line as well as the tank this weekend
Thanks
Bill

[Shifty]

It's actually easier (with friend to help tilt it back), or an engine hoist or other overhead hoist, etc...just be sure to brace the bed .   Honestly, it's much easier, I've done it many times with my TBI trucks fuel pumps/hoses, etc...

[ehjorten]

I have done two trucks with dual tanks, by carefully lowering them down and then disconnecting. I have done this all by myself. It isn't that hard, but if you feel inclined to remove the bed or at least loosen it and move it back, that would be much easier in terms of working on, disconnecting, reconnecting, and routing the fuel hoses.

[Customdeluxe81]

Ehjorten, can you offer any hints on how the to get to the hoses with only one person because I’ll be doing this myself. I really don’t want have to move the bed at this time with only one person.  So what tricks do I need to learn? And from which angle should I attack this project? I know the book says to just drain the tank, support it, remove the bolts from the fuel tank supports and disconnect all wires and hoses and remove tank..... install in reverse. The short hoses that go over the frame look like they are going to be a night mare so advice from someone that has been there and done that would be welcome.
Thanks
Bill

[VileZambonie]

All you need is a 1/4" drive ratchet, long extension and your socket set & you can get to the clamps easily.

[Customdeluxe81]

Vile, that may work if these were regular hose clamps (when did Chevy use those ?) these are the annoying three tab spring clamps..... the ones that make you use bad words when you have to remove them. And once the clamps are removed those hoses have been on for 40 years, and, most likely, won’t come off easy. I find that I usually have to cut the hose or twist the hose to get it to break free.
Bill

[DanMcG]

You should replace the lines if they are original, so cut them and then remove the tank.

[Customdeluxe81]

Dan, there’s no question that I’m going to replace all of the rubber lines, that’s a no brainer, I even got the rubber tank fill and vent lines, as well as a new tank sender because I only want to do this job once.

[Shifty]

Once the lines are cut, the tank will drop, and you can install the clamp of your choosing.

[ehjorten]

Ehjorten, can you offer any hints on how the to get to the hoses with only one person because I’ll be doing this myself. I really don’t want have to move the bed at this time with only one person.  So what tricks do I need to learn? And from which angle should I attack this project? I know the book says to just drain the tank, support it, remove the bolts from the fuel tank supports and disconnect all wires and hoses and remove tank..... install in reverse. The short hoses that go over the frame look like they are going to be a night mare so advice from someone that has been there and done that would be welcome.
Thanks
Bill

Bill;

My technique involves at least one hydraulic jack. If you have two similar hydraulic jacks that would be more stable, but I put a long board on the jack and center it on the tank. It works best if the tank has minimal fuel in it. the fuel will want to slosh, so you have to sometimes watch the balance of the tank. Basically, take the tank loose at the frame brackets (tank still attached to the brackets). Earlier trucks seem to have weldnuts on the brackets so removing the bolts is a simple, one-sided affair, but on my 1991 for instance the brackets are held on with nuts and bolts and it makes the removal process a bit more trying. When you get it loose, you just slowly lower it with the jack, watching the balance of the tank and making adjustments as needed. As you lower it you watch the lines and sender/fuel pump connection.
Access to the hoses and electrical connection is from the front side of the tank. You will have to tilt the tank on the jack and then you can crawl under the truck and pop your head up in the space created between the bottom of the floor and the top of the tank as it is tilted. Disconnect everything and then lower it the rest of the way!
With the tank centered on the jack and long board it is stable enough that it won't fall off and the hoses connected won't allow it to tilt to the point that it will totally fall. That last hose connection you disconnect will allow the tank to be free, so when you do that, you have to keep an eye and/or hand on the tank. It is a little bit tippy and when the fuel sloshes from one end to the other it exaggerates it a bit, so you just have to be aware.
I don't feel like it it all that difficult to do by yourself, but maybe I am just super capable? I don't know. I do most things by myself and just get creative because I usually don't have a friend close by that is willing to help at the moment I need it. When I built my shop, I ended up setting all 25 trusses by my self!

It is a good idea to replace the hoses. If you are working on a fuel injection truck you want to use fuel injection rated hose. Be aware that fuel injection rated hose is kind of stiff and won't want to make the weird bends that the stock hoses have to make. When I did my '91 I just used hose that was the same length as the originals. I had one tank that the main fuel hose got kinked and wouldn't supply fuel at pressure. I had to take the tank down and redo the hose routing. When I did that with the fuel injection hose, I made the hoses longer and I made them go in a loop rather than what I will call a bell shape the shorter hoses needed to bend into. If you are dealing with a carbureted truck, like my '77, then you shouldn't have any issues with just making new hoses the same length as the original ones.

Oh...and I usually just slit cut the ends of those old hoses to get them off because I know I am going to replace them anyways, if they give me any grief on trying to remove them. That way you can still use the hose to measure for a new one.