In another thread here. https://classicoldsmobile.com/forums...ssions-180758/

I mentioned that my fuel gauge needle was stuck at the three o’clock position. @Fun71 provided a test that I used to determine that the gauge and wiring were OK, (thanks Kenneth!) so that meant I would need to drop the tank and take a look at fuel level sending unit. Not something I was joyfully looking forward to, but an inoperable fuel gauge isn’t a good thing either.

So, I put a two gallon fuel can in the trunk, and drove it out of gas. Put 2 gallons in, and drove it home. Then…

got into the tank removal process. Found that the tank looked to have been dropped once before. I found original strap hardware on one side, and replacement stuff on the other. One strap and hardware came out easy, the other took a Sawzall to cut the 3/8” bolt. One thing that really baffled me was the 1/4” hardened Sheetmetal screw at the back end of the strap. The threads had been worn away,(can’t see it, didn’t know it) and the screw just freely turned and did not back out. Not knowing what I had, I proceeded to hack away at the screw until I had it out. Learning what was going on, the other side I took visegrips and locked on to the head of the screw and pulled down on it while backing it out. Worked great!

Here is what the tank area looks like after dropping the tank.


I found three vent lines to the tank. One on each front corner (5/16”) and one in the middle, (3/8”) it was easiest to just take a real sharp knif and cut them in the middle, remove pieces later while on sawhorses and easier to work on. These vent lines went to a series of steel tube pipes right above the differential. None of them had hose clamps on them. Looked to me like just a way of providing expansion and contraction control. But all the old rubber was bad, so I pulled it all apart and replaced with new fuel line rubber. 3 feet of 5/16” and 3/8” will do entire tank area.




Here’s a close up of the fuel vents above the differential


Here are all the new fuel venting hoses above the differential, replaced. No hose clamps on any of them. But the tubes have a flare about an inch from the ends that prevent the new hoses from moving.



The old sending unit next to the new unit. I am not impressed with the plastic float. Looks like it could easily come lose from the wire arm.


I found that the old unit lost electrical continuity where the strap meets the electrical wire connector.


I took some stainless steel wire and McGivered the float a little better.


Old and new hardware. I found that Ace Hardware had the 1/4” hardened rear strap screw, in stainless steel. So a good upgrade. I would have bought the front 3/8” by 4” long bolts in stainless, if they had them. But had to settle on grade 8 bolts with a 3/8” nylock stainless steel nut. I am happy with this, as it should be a less corrosive arrangement.. The pencil is pointing to the Area on the 1/4” Sheetmetal screw where the threads are missing. So if you pull down while turning the screw, it will engage and back out.






The tank, ready to go back in place. Note the the new rubber vent and fuel lines.


I bought a new fuel sender wire harness off eBay.


Using a floor Jack and wood directly under the tank made it easier to position. Also, note that the rear wheels are sitting on 5” of wood, to provide the needed vertical distance to remove and replace.