How this system works:
The petrol cap and petrol tank is a very straightforward system. The petrol cap has outward thread (like a bolt), while the head of the petrol tank has inward-facing threading (like a nut). The petrol cap screws into the top of the petrol tank, which keeps the petrol securely in the tank, and keeps debris from contaminating your fuel tank. When you are at the petrol station and ready to fill up, the petrol cap easily unscrews so that you can top off your fuel tank.
Common reasons for this to happen:
There are three common reasons why your petrol cap might get stuck on:
- Vacuum sealed: Under certain conditions, your petrol tank can create a vacuum-like seal around the petrol cap, which seals the cap tight. This vacuum situation occurs when the pressure inside the petrol tank changes, which can happen due to extreme changes in weather or altitude, among other things. This high pressure situation creates a vacuum seal that makes it nearly impossible to unscrew your petrol cap.
- Poorly threaded cap: Be it out of haste or simply not noticing, sometimes people screw on their petrol caps incorrectly. If the thread does not match up, you can sometimes force the cap on, just like you can force a glass jar lid on even when you’re not screwing it on correctly. If this happens with your petrol cap, it can be extremely difficult to get off.
- Debris in the threading: If dirt, leaves, or any other form of debris contaminates the petrol cap and petrol tank threading, the cap can easily get stuck. This debris can get trapped in the threading, creating extra pressure and friction, making the cap resist that much more when you try to unscrew it.
What to expect:
A top-rated mobile mechanic will come to your home or office to determine the cause of the petrol cap that won’t open, and will then provide a detailed inspection report that includes the scope and cost of the necessary repairs.
How it’s done:
A mechanic will use a specialty wrench to help unscrew the petrol cap. After the cap is off, the mechanic will determine what the cause of the problem was, and repair or replace any damaged parts.
How important is this service?
If you can’t get your petrol cap off, you have a limited distance that you can drive. You never know when you’ll need your vehicle, so it’s never a good idea to be stuck with a finite number of miles. You should have your petrol cap fixed the moment you notice that it’s stuck, so that you can rely on your car anytime that you need it.