Repair / From Ekaterina Larina
- Malfunction of the fuel tank cap
Freezing of the gas tank flap - Hatch pin jamming
- Opening the lid without a key
Video: opening the lid without a key
- Required Tools
Video: drilling out a broken cover
- Replacing the gas tank flap
Video: replacing the gas tank flap
The gas filler cap does not affect the driving performance of the vehicle. Obviously, this is not as important a component as the engine or suspension. However, a faulty fuel tank cap can cause serious trouble for the car owner.
Fuel tank cap device
The gas tank cap is a fairly important element of the car's fuel system. Its design is determined by the design of the neck and the characteristics of the fuel system. The covers differ in the following parameters:
- by thread pitch;
- by type of thread (external or internal);
- by volume;
- according to the depth of immersion in the neck.
Standard covers are screwed into the neck of the tank.
The design of the covers also differs. The simplest ones perform only one function - they close the tank tightly and hermetically. More complex covers have valve mechanisms, locks and coded locking devices. Valves allow you to relieve excess fuel vapor pressure, and locks prevent access to the tank for unauthorized persons.
The fuel tank cap, made using modern technology, is designed to prevent the release of fuel fumes into the atmosphere.
The design of the fuel tank cap is developed individually for each car model
Detailed classification of gas tank caps
The motorist must understand that the cap is not just an element that blocks access to the tank. In a modern car, it also performs a number of other functions: it stabilizes the pressure inside the fuel tank, isolates gasoline or diesel fuel from the negative influence of the external environment, etc.
The fuel tank cap is an important functional element of the car.
The design of the element depends directly on the shape of the neck of the fuel tank. To the greatest extent, everything is determined by the diameter of the thread and the type (it can be external and internal). The depth of entry of the lid into the neck, volume, etc. also matters.
The cover material is always selected taking fire safety into account. This is especially important for cars equipped with gasoline systems. This type of fuel tends to explode under excessive pressure and is more sensitive to the effects of vapors.
Structurally, covers are divided into several types:
- The first option is the simplest. The lid is equipped with a single function - isolating the fuel liquid from the atmosphere.
- The second option is a complex system equipped with valves. The latter ensure stability of pressure inside the tank.
- Lids with lock. In addition to their basic functions, they protect the fuel tank from unauthorized entry.
- Models with memory. Such covers are specially designed for forgetful motorists; they are connected to the tank neck or hatch with a chain.
The cover with a plastic holder or chain is specially designed for forgetful car owners
In addition, covers are classified according to the type of locking mechanism:
- bayonet type, which close by changing the angle;
- threaded;
- shut-off, like on metal cans.
Bayonet and threaded caps are most often used. The first ones are easier to close and open, but they are rarely installed on passenger cars, mostly for tractors and trucks.
Threaded caps can be either internal or external threaded. The difference is in the location of the main and counter threads on the neck of the tank or the cylindrical surface of the lid.
Covers are also divided according to ventilation parameters:
- Valveless models are installed in fuel tanks that have autonomous systems for stabilizing pressure and capturing fuel vapors.
- Single-valve lids are equipped with tanks in which only a fuel vapor recovery system is used, but there is no separate stabilization system.
- Finally, lids with two valves are installed on tanks without autonomous systems. Their purpose is to stabilize the pressure when the gasoline level drops and to release fuel vapors.
Single-valve lids are most common these days. This is due to the design features of modern car models, equipped only with an autonomous fuel vapor recovery system.
Covers are also classified according to the type of theft protection:
- Standard options that do not have any protection.
- Models with a padlock suspended on special brackets.
- Lids with a conventional lock, the cylinder of which is vertically built-in.
- Code caps.
- Models with a lock that can be opened with the ignition key of a specific vehicle.
Standard covers have become more common because they are easy to install. However, recently there has been a demand for lids with combination locks. The padlock is practically out of use today. And covers with a lock that can be opened with the ignition key are found on some top foreign cars.
Fuel tank caps can also be classified according to the presence of additional components:
- with chain or plastic connector;
- with a special grooved handle for easy opening.
And finally, they can be metal or plastic, universal or designed for one car model.
How to open different lid models
Fuel tank caps can open in different ways. As a rule, this is easy to do on domestic cars, but on foreign cars it is much more difficult. To open the code hatches, you have to set the required ratio of numbers. In a word, as many models as there are so many ways of opening.
- A hatch that opens by pressing the corresponding button in the cabin. It is located either on the driver's side door or on the armrest.
The gas cap control button is located on the driver's door
- A cover that can be opened using a standard remote control for the central locking system. In this case, the hatch wiring is paralleled with the door locks.
- A version of the hatch that opens with a lever with a picture of a gas station. The lever, like the button, is located on the threshold of the driver's door.
- Simple lids open by lightly pressing them until they click. Then, holding the notch, you need to pull the hatch towards you.
The lid with a recess opens by pulling towards you
Fuel tank cap malfunctions
A hissing or popping noise when the lid is unscrewed is not a sign of a malfunction. This is how the valve works, through which fuel vapors escape from the tank under pressure.
Freezing of the gas tank flap
During the cold season, it is often impossible to open the gas tank flap. The fact is that it is not the hatch itself that freezes, but the mechanism that unlocks it. The reason for this is condensation freezing as the temperature drops.
The reason the hatch freezes is condensation, which freezes when the temperature drops.
The only way to eliminate this nuisance is to locally warm up the body. You may not be able to find a burner at a gas station, so the best option is to use WD-40 all-purpose lubricant. Having poured it into the syringe, you need to process the tank hatch through the rubber band, then, after thawing, sharply open and close the lid several times.
Hatch pin jamming
If the gas tank cap is difficult to open in the warm season, the reason for this is the jamming of the plastic pin of the flap. In this case, the hatch lever located in the cabin is usually faulty - over time it begins to jam.
You need to try to give the lever in the cabin the greatest amplitude, then the pin will pop out and the gas tank will open. In any case, you can prevent such a nuisance: just periodically lubricate the rubber seals and the pin itself with WD-40.
A universal lubricating fluid that can prevent rubber seals from freezing and soften them for better performance.
Opening the lid without a key
Car owners often lose or break keys to locking covers. A screwdriver and a self-tapping screw will help here. A self-tapping screw screwed into the lid will unlock the lock, and the lid can be easily removed. However, in this case a new cover will be required.
If the key is lost, the cover can be opened using a screwdriver and self-tapping screw.
Video: opening the lid without a key
Common faults
When the vehicle is actively used, the fuel tank cap deteriorates. In any case, there is no need to panic, almost all problems are easily fixed, and sometimes the cover can be easily replaced with a new one. The list of the most common malfunctions includes:
- freezing of the mechanism;
- plastic pin stuck;
- damage to the lock cylinder, etc.
Cover freezing
Freezing of the lid often happens during the cold season. The owner drives into a gas station to fill up and cannot open the tank. The hatch mechanism that maintains normal unlocking freezes. At low temperatures, the plastic pin hardens and is no longer recessed inside.
Freezing of the gas tank cap occurs as a result of the difference in air temperature outside and inside
Of course, this is not the fault of the automaker. The designers initially took care of the cover material at the development stage. In most cases, it is frost-resistant, but while driving the interior becomes very hot, hot air vapor circulates throughout the entire interior of the car, including the lid mechanism. The latter “presses” frost on the reverse side at low temperatures.
Thus, condensation forms on the lid. The pin is closest to the cold air. Moisture turns into ice, the hatch opening mechanism hardens, and the lid does not work well.
What to do? Obviously, the solution suggests itself. It is necessary to warm up the frozen parts, this will lead to the thawing of the mechanisms and their performance.
To open the hatch cover in cold weather, just spray hot water from a thermos on it. The ice will instantly thaw and the mechanism will open.
Pin jam
If the lid does not open during the warm season, this is most likely due to the plastic pin being locked. Many modern hatches are controlled from the interior using an automatic lever. The latter can “walk” with difficulty and remain motionless when lifted. In such a situation, the cover will not react to the driver’s manipulations, since it is in the closed position, held by its pin, which is released when the central lock is opened.
The problem is solved with the help of an assistant. You can ask the passenger to hold the lever from the passenger compartment, and press the hatch from the outside. As soon as the lid opens a little, the motorist must react and pick up the hatch. If there is no assistant, the lever can be fixed in one position with a driver's mat or other object. To avoid damaging the car's paint, it is recommended to wrap the screwdriver in a cloth.
If the gas tank does not open, you can carefully pry it off with a knife or screwdriver
Under the trim in the luggage compartment on some cars there is an electric drive designed for emergency opening of the gas tank in the event of a malfunction. It is usually closed by a lid. To open the hatch, you need to insert your index finger into the rectangular hole, feel for the pin and slide it in the opposite direction.
Thread breakage
If the lid is threaded, it is less prone to breakage. However, if this happens, it cannot be unscrewed; the tank can only be opened by disassembling or breaking it. There is simply no other alternative extraction method.
Owners of cars with such a cap are advised not to allow the fuel tank to become completely empty in case they have to drive to the nearest service station.
Opening a broken lid with a lock
Sometimes the lid with the built-in lock breaks. To solve this problem, you will need to drill out the cover.
Required Tools
To drill out the lid with a lock you will need:
- hand drill and 3 mm drill bit;
- metal rod or pin with a diameter of 3 mm;
- screwdriver with a thin straight blade.
A hand drill will help you quickly and safely open a broken lid with a lock.
Procedure
You can try to avoid drilling as follows:
- twist the key in different positions of the lid - often as a result of this it opens;
- twist the lid itself, warping its outer part - the lock tongue can come out of the socket and the lid will open.
To avoid drilling the cover, you should twist it in different positions.
Drilling the cover is carried out as follows:
- Through holes are drilled in the corners of the lid.
- Rods with a diameter of 3 mm are inserted into the holes.
- The lid is unscrewed from the neck.
It is recommended to use hand tools as they are safer than electric ones.
Video: drilling out a broken cover
Drilling with a drill is only possible in the garage and with a minimum amount of fuel in the tank. This is especially true if you are using an electric drill.
Replacing the lid lock code
The cover with a code protects the fuel tank as much as possible from access by unauthorized persons. However, sometimes car owners forget the code, or there is a need to change it. To change the code (there are 144 combinations in total), you need to insert a thin screwdriver blade into the lock and, after clicking, pull it out. After this, the cover can be easily removed.
This procedure can take one minute or 20, because the cover with the code has a rather complex design.
After dismantling, the old code is reset automatically and it becomes possible to replace it.
When installing a cover with a code, you must immediately remember or record the selected digital combination somewhere
Fuel tank cap repair
The tank cap is easier to replace than to repair. The price of a simple lid is 100–200 rubles, a lid with a lock is about 350 rubles. More complex designs are more expensive, but you can immediately solve all problems with the operation of the lid.
If it is not possible to buy a new cover, you can try to repair the old one. This can be done even in road conditions.
Replacing the gas tank flap
Replacing the fuel tank flap if it is found to be faulty is quite simple. The work is performed in the following order.
- Open the trunk.
- From the side of the neck the casing is bent.
- The motor found under the casing is unscrewed with a screwdriver and pulled out along with the pusher.
- Unscrew two large screws securing the hatch.
- The hatch is pulled out along with the lid. The cover is removed.
Removing the fuel tank flap is quite simple.
A new one is installed in place of the old flap. Assembly is carried out in reverse order.
The fuel tank flap can only be removed from the inside, since it is fixed on the side of the lid
Video: replacing the gas tank flap
Replacing the plastic cable for the hatch
If the plastic cable fails, it can be replaced with ordinary plastic clamps of suitable length. You will need three of these clamps:
- The first clamp is threaded through the eye of the fuel tank cap and tightened as much as possible so that the loop is tight enough.
- A second clamp is connected to this loop.
- A small hole is drilled in the gas tank flap through which the assembly assembled from clamps is passed.
- A third clamp is attached to the assembled assembly.
Ordinary plastic clamps can perfectly replace the cable in the tank locking device
This whole simple design can replace a failed cable. In addition, if necessary, you can always quickly replace a frayed clamp with a new one.
You can replace the gas tank flap cable using ordinary plastic clamps
Valve mechanism repair
The main purpose of the cap valve mechanism is to regulate the fuel vapor pressure in the gas tank. With prolonged use and wear, the valves no longer cope with their tasks. If it is not possible to replace the entire cover, you can repair the mechanism as follows:
- The gas tank cap is unscrewed.
Before repairing the valve mechanism, the cover must be cleaned and dried. - A screwdriver blade is inserted between the safety belt loop and the sealing ring and the ring is removed.
Remove the O-ring very carefully - Using a screwdriver, press the holes in the mesh and pull out the springs.
Stretched springs are trimmed into two or three turns - The stretched springs are trimmed into two or three turns and installed back into the valve.
- The lid is assembled in reverse order.
Video: repairing the fuel tank cap
Secrets of opening the lid without a key or code
Keyed cap models have become quite common these days. Most modern foreign cars are equipped with them. In addition to its basic functions, such a cover prevents unscrupulous neighbors from stealing gasoline from the fuel tank. But if the key is lost or broken, the owner himself will not be able to open the tank.
Fuel tank cap with key protects against theft
The design of such covers implies the presence of two parts: external (movable) and internal (fixed). They rotate relative to each other, preventing the lid from opening. The key acts as a lock for one of the parts; accordingly, by inserting it inside the cylinder, you can open the hatch.
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Required Tools
Here's what you need to prepare for quick and fruitful work:
- self-tapping screw;
- screwdriver;
- drill.
Repairman actions
All work is carried out carefully and consistently:
- The cover is drilled in this place and a self-tapping screw is screwed in. This is necessary in order to connect both parts of the lid.
Drill the cover in this place
- After screwing in the self-tapping screw to 75–80 percent of the depth, both parts of the cover are connected, and it can be unscrewed with your fingers.
Unscrew the cover after screwing in the screw
The cap can now be unscrewed and screwed in without using a key. You can leave this matter like this and wait a while before replacing it. The cover with a self-tapping screw will perform its functions for a long time, but without a key.
Opening the code cover
There are also code covers. The principle of operation in them is similar to caps with a key. One part is movable with numbers, the second is fixed. The car owner, who knows the code, fixes the moving part of the cover in one position, for example, as in the photo - 5 and 11, and opens it.
Code cover installed on 5 and 11
In terms of reliability, such covers leave much to be desired. Especially those covers that are installed on VAZ cars. Imported models are made little better. Their disadvantage is that in a few minutes of painstaking selection you can open the lid by typing the code.
The cover code can be changed at any convenient time. To do this, you just need to consistently perform a series of elementary actions:
- From the back of the cover, remove the retaining ring using a screwdriver or other similar tool with a sharp pin.
Remove the retaining ring from the back of the cover
- Next, remove the part of the cap that screws onto the neck of the gas tank.
Part of the code cap that screws onto the tank neck
- Then you need to remove the springs and matrix retainer.
- Now you should remove the matrices.
The code cover matrices are also removable
These same matrices are the details that create the code. In order for the lid to open, these two crescent-shaped notches must come together.
The half-moon notches should line up
They must be connected under this matrix, one hole of which is made large.
Large size code cover hole
To create a new code, you need to remove all matrices. Then you should set any code by turning the moving part of the cover. Reassembly is carried out carefully and carefully, so as not to forget to put all the dies, springs and cotter pins in place.
Useful tips
Silicone lubricant or water-repellent WD-40 will help you avoid troubles associated with opening the fuel tank cap. If they are unavailable, you can use regular motor oil. These products should be used to treat the rubber seals on the lid after washing the car, regardless of the time of year. This will not only reduce the risk of the lid seizing, but will also extend the life of all rubber elements.
On some models of modern cars, the gas tank cap may not open if the engine is running and the ignition key is in the lock. That is, in order to open the lid, you need to turn off the engine and remove the key from the lock.
Timely lubrication of the gas tank cap can prevent unexpected troubles along the way
. Thus, a regular cap on the fuel tank of a car can create a lot of troubles. However, carefully following the recommendations of professionals will help to avoid them. Good luck on the roads!
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Heat the key with a lighter and carefully try to open it
To increase security, many owners of modern cars install a lock inside the hatch cover. During winter temperature changes, the moisture accumulated in the castle can freeze.
In the absence of special automotive chemicals, you can use improvised means. For example, use a lighter to heat the key and try to insert it into the lock.
Often this method works. On the other hand, under no circumstances should you use open fire or hot air. This may cause a fire as the lock tends to accumulate flammable gasoline fumes.
