GM 3.0 Diesel Fuel System Cap
GM Capless fuel system Dust/Moisture cap. Protect your vehicle's fuel system from unwanted dirt or water.
This is specifically for the Duramax Diesel capless fuel system on the Silverado Sierra 3.0L Duramax Diesel engine. If it doesn't have that specific engine in a Half-ton pickup I cannot guarantee fitment.
Made of 3D printed TPU material giving it a tough, reliable fit.
Newly Designed with a Magnet for attaching it to the fuel door when not in use.
Just slide it onto your fuel filler neck and it'll keep all the debris away.
FAQ:
Your cap does not come with an o-ring, why not?
Answer: Two reasons really, vacuum and pressure. Your fuel system is vented through the fuel fill. If the cap had an o-ring on it there is a chance that it would seal too well. By that I mean that as fuel leaves the fuel tank something needs to take the place of the fuel leaving the tank. That’s usually air. If the cap seals too well then air can’t get in and your engine will starve for fuel. Also while your vehicle is running it is returning some fuel to the tank via a fuel return line. This fuel is very hot which will increase the pressure in the tank. Since your tank is usually vented through the fuel fill and there is always some fuel leaving the tank while your vehicle is running this isn’t usually a problem. When you shut your vehicle off all of that fuel does what is called a hot soak or heat soak. Since there is no longer any airflow to cool the fuel down the temperature in the tank can rise causing pressure build up in the tank. If the cap seals too well the pressure can build up to such an extent that that fuel or fuel vapors will push out around the cap and spill on you or your vehicle. The vehicle fuel tank will then cool creating another vacuum on the tank possibly causing a hard start or no start condition again starving the vehicle of fuel.
If your cap doesn’t seal the system what is the point in having it?
The answer for this is threefold. Dust, Moisture and Inattention. Just because it isn’t a vapor seal doesn’t mean it isn’t working. The cap overlaps both the inside and the outside of the fuel filler making it almost impossible for water or dust to get in there. The third reason is probably the most expensive. It can be used as a stop-gap to keep someone from accidentally putting gas in your diesel truck or even worse DEF. Just the fact that something is on there and there is one additional movement to fuel your truck can be the difference between a normal day and one that costs you several thousand dollars.
Why is your cap made of plastic and not some other material like billet aluminum?
The biggest reason is that I am a 3D printing company and metal 3D printers are not up to the challenge of creating something like this out of metal at a reasonable cost. When it really comes down to it fuel caps have been made out of plastic for decades so while it doesn’t sound as cool to say that you have a plastic fuel cap it is very durable and will probably outlast the vehicle.
GM 3.0 Diesel Fuel System Cap
GM Capless fuel system Dust/Moisture cap. Protect your vehicle's fuel system from unwanted dirt or water.
This is specifically for the Duramax Diesel capless fuel system on the Silverado Sierra 3.0L Duramax Diesel engine. If it doesn't have that specific engine in a Half-ton pickup I cannot guarantee fitment.
Made of 3D printed TPU material giving it a tough, reliable fit.
Newly Designed with a Magnet for attaching it to the fuel door when not in use.
Just slide it onto your fuel filler neck and it'll keep all the debris away.
FAQ:
Your cap does not come with an o-ring, why not?
Answer: Two reasons really, vacuum and pressure. Your fuel system is vented through the fuel fill. If the cap had an o-ring on it there is a chance that it would seal too well. By that I mean that as fuel leaves the fuel tank something needs to take the place of the fuel leaving the tank. That’s usually air. If the cap seals too well then air can’t get in and your engine will starve for fuel. Also while your vehicle is running it is returning some fuel to the tank via a fuel return line. This fuel is very hot which will increase the pressure in the tank. Since your tank is usually vented through the fuel fill and there is always some fuel leaving the tank while your vehicle is running this isn’t usually a problem. When you shut your vehicle off all of that fuel does what is called a hot soak or heat soak. Since there is no longer any airflow to cool the fuel down the temperature in the tank can rise causing pressure build up in the tank. If the cap seals too well the pressure can build up to such an extent that that fuel or fuel vapors will push out around the cap and spill on you or your vehicle. The vehicle fuel tank will then cool creating another vacuum on the tank possibly causing a hard start or no start condition again starving the vehicle of fuel.
If your cap doesn’t seal the system what is the point in having it?
The answer for this is threefold. Dust, Moisture and Inattention. Just because it isn’t a vapor seal doesn’t mean it isn’t working. The cap overlaps both the inside and the outside of the fuel filler making it almost impossible for water or dust to get in there. The third reason is probably the most expensive. It can be used as a stop-gap to keep someone from accidentally putting gas in your diesel truck or even worse DEF. Just the fact that something is on there and there is one additional movement to fuel your truck can be the difference between a normal day and one that costs you several thousand dollars.
Why is your cap made of plastic and not some other material like billet aluminum?
The biggest reason is that I am a 3D printing company and metal 3D printers are not up to the challenge of creating something like this out of metal at a reasonable cost. When it really comes down to it fuel caps have been made out of plastic for decades so while it doesn’t sound as cool to say that you have a plastic fuel cap it is very durable and will probably outlast the vehicle.