Removing fuel tanks

[Old Guy Bill]

You've also got a sending unit ground wire that attaches to the frame...

 

[Radiohead]

I’ve unbolted the L brackets from the frame already expecting the the tank to drop down enough to cut the lines but the tank won’t drop, I’m assuming the lines are what’s holding it up there, the fill hose & vent hose are already cut off too. The metal lines are bolted down on both ends on top of the damn crossmember so no access there either.

The strap bolts stick out a little and have holes in the frame to catch on. If you have all the bolts for the brackets out, and give the tank a little man handling towards the center, it should fall out as far as your wires and hoses will let it. Don't put any pull on that ground wire, it's welded onto the sending unit and is a bitch to fix. Use a floor jack under the tank for support and it will be orders of magnitude easier.

 

[75gmck25]

I’ve had both tanks off my K25 to replace sending units, and if the tank is relatively empty it’s not a bad job.

- Disconnect the ground wire from the frame, and loosen up (but leave the nuts on) all the bolts that attach the L brackets to the frame. Also take the screws out that hold the filler neck to the truck bed.
- pull the tank outward until it’s it barely held on the frame bolts, and then slip a floor jack under it. The best type is a rolling scissor jack, since you have good control of how fast it drops. Use a short 2x8 or 2x10 between the jack and the tank to spread out the load.
- take the nuts off completely and then slide the tank further out so it drops off the bolts and onto the jack.
- shuffle the tank around a little so you can reach up and cut the old rubber lines with tin snips or whatever end cutter pliers you have.
- as you lower the tank down, disconnect the sending unit wire, and also guide the filler hose down around obstacles so it drops down with the tank. It always seems to catch on something.

Reinstallation is the reverse, but use longer rubber hoses to make it easier. It is best if the new hose is SAEJ30R7 (low pressure) or SAEJ30R9 (high pressure) EFI fuel hose because it will hold up better when used with ethanol-added fuel. Most parts stores have it by the foot, but I found it cheaper to buy 10 foot sections from an Amazon supplier.

 

[Broken85]

Reaching up & cutting the lines is a no go, I can barely get my hand up in there let alone cut anything, the tank has to be lowered to reach anything and the rubber lines are only about 3-4” long so the tank will not drop after brackets have been removed it just sets there and tilts to one side just a little bit but the wrong direction for me still reach lines, then I still have to be able to reassemble when I’m done with cab repairs. I’m not a newby I’ve been wrenching for 50 years and just retired from body shop after 24 years, I’ve looked at this from every possible angle and to me bed has to be moved.

I have always been able to reach the hoses to cut them by sticking my arm in the wheel well to get to the top of the tank. I haven’t had to take a bed off to drop a tank yet.

 

[ss454elco]

You may have to loosen the straps. I did with mine because the threaded end stuck through the frame.

 

[1978C10]

If you replace the tank it's easy to mount brackets incorrectly to the new tank and holes in frame won't match with bracket holes. Also I cut two 3/8 bolts into studs with a point screwed them into frame one on front location and one on rear to hold up tank and guide other bolts on. Also don't mix Brackets front to rear they are different.