If your fuel dash gauge starts to register intermittently, readings fluctuate, or it just plain quits, it can most often be traced back to the fuel tank sending unit. These units are always sitting in fuel. They are constantly moving and they are subjected to vibrations. This is why they are most often the cause for faulty or no readings on the dash gauge. Replacing a Corvette fuel tank sending unit is a relatively easy job that can be performed by anyone with a few good hand tools. When Project 64′s sending unit quit working, we contacted Zip Corvette Parts, Inc. They were able to supply all of the Corvette parts we needed to complete the job. Before you start, there are some things you should keep in mind. Run as much fuel as you can out of the gas tank. It is much easier to drain 4 or 5 gallons of gas than 20. Always work in a well ventilated area and wear eye protection. With those few tips in mind, let’s get started.
Click on the images for expanded views – it’s much easier on the eyes.
01: Here are the parts Zip sent: A reproduction Corvette sending unit, Sending Unit Gasket, the Locking Ring and the Locking Ring Wrench. You will also need a drain can compatible with fuel, some hand tools, rubber fuel hose and clamps, emery cloth or sandpaper, hydraulic jack, jack stands, eye protection, and, of course, a shop manual for your car.
02: Start by disconnecting the battery. Then remove the Corvette spare tire and carrier support from the car.
03: Now remove the spare tire carrier. It is held in by the carrier latch support assembly and four additional bolts.
04: Carefully cut the rubber hose that goes from the sending unit to the frame fuel line in half. Put a 3/8 bolt into the frame line end and let the sending unit end drain the remaining fuel in the tank into your drain pan. The reason I say to cut the rubber fuel hose instead of saving it, is that I never recommend re-using the old rubber fuel hose. It is much safer to use a new hose and it is much easier to do now than when everything is reassembled. Also, use a drain pan that is recommended for fuel use.
05: When the fuel is drained out, take the Corvette sending unit locking ring removal tool, place it on the locking ring tabs and unscrew the ring. This tool sure beats using a hammer and screwdriver which is a method some people still use.
06: It is a good idea to thoroughly clean the sending unit contacts. To remove the spade connector from its retainer, slip a small screwdriver into the receiving end, release the spade retainer tab. Now slide the spade connector out of the back of the retainer. You can now thoroughly clean the contact point. When you are finished, slide the connector back into the retainer and lock it into place.
07: Take a new gas hose and using the old hose as a guide, cut a new length of hose. It is also a good idea to replace the fuel hose clamps while you are at it. Zip Corvette has available gas tank sending unit hoses that are pre-cut with correct style hose clamps.
08: Before you install the new sending unit, it is a good idea to compare it to the old unit. Make sure the bends and connections are where they should be. It is easier to find out if there is a problem now then after you have installed it.
09: Here is something that you want to do before you install the sending unit into the tank. Connect the sending unit wires to the sending unit and re-connect the battery. Have a friend sit in the car. Turn the ignition on and watch the fuel gauge. Holding the sending unit in your hand, SLOWLY move the float on the unit. If everything is connected correctly and the dash gauge is good, the dash needle should move in accordance with the float. If it does, then you know everything is A-OK and you are ready to re-install the sending unit. If the gauge does not work correctly, then the problem lies with the wiring or the dash gauge. Remember to disconnect the sending unit wires and the battery before you continue.
10: Carefully slide the sending unit into the fuel tank. Make sure that you place the sending unit gasket onto the sending unit before you install it. (In this picture you can see it is already on the unit.) When the sending unit and gasket are in place, slide the locking ring down over the sending unit tabs.Then take the locking ring wrench and tighten the locking ring until the locking tabs rest against the tank stops. Now install the new fuel hose and clamps. Re-connect the sending unit wiring and re-install the spare tire carrier assembly. Re-connect the battery, replace the fuel and you are done. The fuel gauge is again working correctly and you are ready for more cruisin’!
1963-1967 Corvette Fuel Tank Sending Unit Replacement
Zip Corvette Parts
8067 Fast Lane | Mechanicsville, VA 23111 | (800) 962-9632
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