Corvette Gas Tanks - Let's Get Tanked

The antisqueak strips are likely to need replacement, and a pair only costs $5. If your hold-down straps are rusted, a new set can be purchased for $40.

The gas tank sending unit has an internal coil of resistance wire that can eventually break due to wear from the slider. consider replacing the unit even if it is not rusted. The failed sending units I've dissected usually wore out at the quarter-tank level. I'd surmise the owners didn't like to fill their tanks. And that was when a gallon of gas cost only...oh, never mind.

The sending unit is held in place in the tank by a lock ring; a rubber seal goes between it and the tank. The fuel strainer comes with the sending unit, but it can also be ordered separately if the sending unit is not being replaced.

Parts located on the top of the tank include the overflow boot, nipple, drain hose, hose spring, and tie-down straps, available together in an Overflow Kit. The purpose of these parts is to drain any gas overflow to the ground during a fill-up, to avoid the exhaust, spare tire carrier, and other parts. The remaining top end parts are the filler neck gasket, screws with o-rings, and gas cap.

After draining the gas tank, remove the spare tire carrier and cover. Use caution when removing the long front bolts; you don't want to break loose their weld nuts inside the frame. A forthcoming article will detail restoration and replacement of these parts.

Slide the clamps out of the way, and then carefully break the hoses loose. If the hoses are being replaced, slit them longitudinally to ease removal. Wear safety goggles and keep your head away when removing the hoses to prevent gas getting into your eyes.

If there's a fuel-vapor separator on your tank, it's located on the top left side. Although it is a challenge to see or reach, treat it gently, especially when removing the hoses. If the separator is original, the plastic will be brittle, and replacements can be hard to find.

Oil the exposed threads and remove the bolt from each hold-down strap. There's no need to worry about the tank falling; it is still supported by the crossbar. While you're there, inspect the framerails for surface rust. When the tank's out, it's an opportune time to brush on the POR-15 rust preventative paint.

Remove the four bolts that attach the tank crossbar to the frame. A 9/16-inch box wrench can be slid inside the frame to hold the bolt head. Leave one bolt on each side connected by a thread, support the tank by hand (it's light when empty), and finish removing the crossbar. Lower the front side to remove the tank.

Two tabs determine the alignment of the sender in the tank. Press the sender against the rubber gasket and engage the lock ring by hand. Then use a punch or screwdriver to slowly tap the cam lock ring around until it is fully seated.

The threaded holes for the filler neck screws open into the tank, so make sure the o-rings are in good shape on each screw. To the left of the filler opening is a pressure-relief valve. This particular one took a while to seat properly.

There's nothing tricky about the installation; it's just the same steps in reverse order. However, before tightening the hold-down straps, check the position of the antisqueak strips between the tank and crossbar or frame, and check that the tank is centered in the frame.