Q: I have a question on my 2004 Corvette. Several times while I am filling my gas tank the pump acts as if my tank is full (pump nozzle clicks off while filling) even when the tank is not full. Numerous Corvette owners that I have talked to about this problem have had the same problem or know someone who has had this trouble.
When I spoke with some owners they were saying that they would get different results at different gas stations. They said that at some fuel stations the pump nozzle would keep clicking off; however, other gas stations gave them no problems filling their tanks at all.
I also remember reading on the Internet where some owners talked about a service bulletin that required a filler hose replacement. I’ve searched for the thread but can’t find it. Could you clue me in on what the problem might be and how to fix it?
I also want to say that I have been receiving Vette magazine for 2 years, and love the magazine.
A: Tina, this is how the mechanism at the gas station works that causes the pump nozzle to click off while filling. Near the tip of the nozzle there is a small hole and a small pipe leads back from the hole into the handle. Suction is applied to this pipe using a venturi. When the tank is not full, air is being drawn through the hole by the vacuum and the air flows easily. When gasoline in the tank rises high enough to block the hole, a mechanical linkage in the handle senses the change in suction and flips the nozzle off.
You are correct, some gas station pumps have a very high flow rate, while other gas stations seem to have a more moderate flow rate. At the gas stations with a high flow rate, when you set the filler nozzle at its maximum they sometimes have a tendency to click off quick as the pressure builds up inside the tank.
You can try putting the gas nozzle not quite as deep into the filler neck of your vehicle. If that doesn’t help, about all you can do is set the nozzle on a lower fill setting to slow down the delivery. That should allow the tank to fill better.
There is a Technical Service Bulletin (TSB #04-06-04-031) that covers the backpressure from the fuel pump continuously causing the fueling nozzle to cut off prior to the fuel tank being full. This TSB covers Corvettes produced from 1997 through 2004.
The TSB repair includes replacing the fuel tank filler hose with part number 10353139 at a cost of approximately $118.89 for the part. This new hose has been redesigned to provide smoother flow conditions.
The Repair Procedure:
1. Safely raise and suitably support the vehicle according to the service manual.
2. Remove the left rear tire and wheel.
3. Remove the left rear wheelhouse panel.
4. Loosen the lower fuel tank filler hose clamp through the access hole in the body using a 1/4-inch ratchet and extension.
5. Loosen the upper fuel tank filler hose clamp.
6. Remove the fuel tank filler hose.
7. Install the new fuel tank filler hose.
8. Tighten the upper hose clamp to 35 in-lb.
9. Tighten the lower hose clamp through the access hole in the body using a 1/4-inch drive ratchet and extension. Also tighten this fuel filler hose clamp to 35 in-lb.
10. Install the left rear wheelhouse panel.
11. Install the left rear tire and wheel.
12. Lower the vehicle.
When you have removed the left rear wheelhouse panel to get to the clamp you will find there is an access hole in the frame you will need to go through to get to the inner clamp. I have had good luck in repairing several vehicles using this method. The total repair time is less than an hour.
So, Tina, I hope this answers your question and you can spend more time driving your Corvette than trying to fill the fuel tank.