How to replace the larva in the door lock. How to change the larva in the castle. Possible causes of a malfunction of the lock cylinder

Some locks require the replacement of the entire locking device when the mask breaks, but there are also mechanisms where only a broken element can be changed. This mainly applies to devices with cylinder locking mechanisms. The replacement of the door lock cylinder is carried out as soon as possible, while the cost of work is significantly reduced.

Possible causes of a malfunction of the lock cylinder

The replacement of the front door lock cylinder is carried out in a situation where the device ceases to function correctly. This may be due to the following reasons:

• natural wear of the part, which occurs after a long time of using the lock. Each lock, in addition to the warranty period, during which there is an unpaid repair of the product, has a certain period of operation. After the expiration of the specified period, it is recommended to replace the device completely or change the main operating mechanism;
• a defective element is installed;

In order to protect yourself as much as possible from low-quality locks, it is recommended to purchase devices from well-known manufacturers, and only in specialized stores.

• the larva is not installed correctly, that is, when installing the lock, the installation technology was violated. How to change the larva in the castle in this case? You just need to carry out all the installation work again, taking into account previous errors;
• unsuccessful attempt to open the lock with a non-native key. The used lockpick may break or simply get stuck in the lock. The correct operation of the locking mechanism may also be disrupted;
• the door leaf warped from moisture or other reasons. This situation may lead to the need to replace the door, lock or cylinder. It all depends on the size and shape of the deformation. How to replace the lock cylinder in the current situation, and under what circumstances can this be done? Replacing the core of the locking device can only help with slight distortion caused by strong impacts or other means of mechanical impact on the door. In other situations, more drastic troubleshooting measures will be required, such as.

How to choose a face

Replacing the core of the lock is not a difficult task, but at the first stage you need to decide on the selection of a new mechanism. The main selection options are:

• mask length;
• device width;
• diameter;
• view of the castle

The length of the larva depends on the size of the lock used and the dimensions of the door, that is, this parameter must correspond to the distance from the outer to the inner part of the door. In the case of using an overhead lock, the calculated distance must be increased by the width of the lock. The maximum distance from the door leaf to the end of the mask is 3 mm. If you neglect this parameter, then the lock can be easily opened.

You should also pay attention to the length of the mask relative to the central rotary cam. It may be the same or different. If the lock uses a core with different side sizes relative to the central part, then larvae having the same dimensions cannot be installed in the lock.

The width and diameter of the locking mechanism depend on the dimensions of the lock used and are determined by its manufacturer.

The type of mask depends on the type of castle. If the lock is mortise, then the device must have holes for the key on both sides. If a padlock is used, then on one side there should be a turnkey well, and on the other a rotary handle.

Not the last role in the selection of the core of the lock is played by the manufacturer of the locking device, who made the lock. Many companies produce standard masks that have certain parameters (the generally accepted European DIN standard has parameters: length - 34 mm, width - 10 mm, diameter - 17 mm). However, there are also non-standard devices. For example, locks manufactured by SuperLock and Mul-t-lock differ in length and diameter.

Replacing the mask on your own

How to change the door lock cylinder? This will require:

• remove the faulty device;
• pick up a new core (selection options are described above);
• install a new hatch.

Removal of the mask

How to change the core in the lock without removing the entire mechanism? The main tool needed for the operation is a screwdriver (you can use a screwdriver). To take out the mask, you will need:

1. on the front plate of the lock, find and unscrew the screw that fixes the locking device. As a rule, it is located in the area of ​​\u200b\u200bthe mechanism itself;

1. Use the key to move the lock to the "open" position. In this case, the locking crossbars will not interfere with the removal of the larva;
2. then you should turn the key a little to make it come into contact with the core and pull it towards you. The core of the castle should move from its place. If this does not happen, then you can twist or just pull the key. The main thing is to provide the larva with free running;
3. take out the mask. If a handle is located on one side of the lock core, then the mask is removed towards the locking handle. In another situation, the core can be removed in any direction.

Sometimes there are situations that the installed additional handles or decorative overlays interfere with the removal of the larva. In these cases, additional work will be required to remove interfering elements. As a rule, they are all held on by fixing bolts, which are easy to find and unscrew.

If the lock cylinder does not lend itself, then a screwdriver can be used to remove it (any other device to facilitate the operation). In rare cases, it is necessary to apply additional lubricant, which can be used as WD-40.

Installing a new larva

Now let's look at how to change the larva in the castle after removing it. Of course, you need to purchase a new device that is fully consistent with the basic parameters. After that, all the operations described above must be carried out in the reverse order. This process is done like this:

1. install the mask inside the castle. At this stage, it is recommended to check the compliance of the core with the lock and the operability of the new locking device;
2. fix the larva with a bolt.

The fixing bolt must not be overtightened and left in a relaxed position. All defects can lead to incorrect operation of the device.

1. install decorative elements and a door handle (if they were previously removed).

You can watch the video on how to change the core of the lock yourself. It visually shows the entire process of independent operation.

The replacement of the lock cylinder is carried out without the help of specialists. However, to ensure the correct operation of the locking device, it is necessary to select a core that completely matches the parameters of the previously installed one, and perform all the necessary work as carefully as possible. Otherwise, you can damage the rest of the elements of the lock and the work done will be useless, as it will require a second procedure or replacement of the locking device.

The larva is the part of the cylinder lock mechanism into which the key is inserted when the door is unlocked. If the lock breaks down, there is no need to buy a whole new mechanism. It is enough to replace its larva, which can be bought along with the keys in a specialized store or on the market. At the same time, the lock does not need to be removed from the door, and all manipulations with it will take 15-20 minutes. How to do this work, you will learn from today's material.

To replace the mechanism, you will need a tape measure and a screwdriver. First you need to remove the old larva and measure its length, width and diameter in order to later buy a new mechanism that is suitable in size. To dismantle the larva, it is necessary to unscrew the bolt fixing it, which is located on the edge of the door. After that, the key should move the constipation to the open position. Now, by clicking on the larva from the outside, you can easily remove it from the lock. With a broken core mechanism or a key stuck in it, it will not be possible to remove the larva in the usual way. Then you need to use a drill with a 10 mm drill and drill out the core of the lock. After such an operation, the larva will be easily removed.

When choosing a new larva in the store, in addition to size, you should pay attention to its color and design. Not bad if the visible part of the new core matches the color of the door hardware. As for the design of the larva, it can have two holes for keys, or one when locking the door from the inside to the “turntable”. Decide which core arrangement is best for you. The cheapest larva is not worth buying. They break easily, as the material they are made of is too soft, like brass, and the lining is rather weak.

Installation of a new larva is carried out in the reverse order. It is inserted into the lock hole, the mechanism cam is turned with a new key to the closed position, and the fixing bolt is screwed into place.

The question of replacing the lock sooner or later arises in almost any owner of an apartment or office. This happens when it fails due to a breakdown or loss of the key, due to the end of its service life or when changing tenants. In most cases, the door lock cylinder is replaced, which is much easier than installing a new locking mechanism.

What is a lock larva

The mechanism responsible for the secrecy of the lock is called the larva, core or secret. It is she who is responsible for security, the possibility of unauthorized opening and penetration of uninvited guests into the premises. A key is inserted into the larva and turns. In this case, the pins inside it line up in a certain combination, and the lock opens. Incorrectly aligned pins, or pins, will not allow the locking bolt to budge, and the door, in this case, will remain closed.

In modern cylinder designs, pins are replaced with washers, rotating blocks, or movable probes. But regardless of the filling, the secrecy of the lock cylinder will depend on the number of components and the accuracy of their manufacture.

Not all existing locking mechanisms installed on the entrance doors have the ability to be partially replaced, some locks have to be removed entirely. For example, code (lever) mechanisms are integrated directly into the body of the lock, so replacing the door lock cylinder in this case is impossible, you will have to remove it and insert a new one.

There are several types of the most popular locks for entrance doors:

• cylinder;
• disk;
• cruciform;
• pin;
• especially complex.

Locks for entrance doors are overhead or more reliable - mortise, with a key locking system on both sides or with inside turntable instead of a key. They are also divided into upper and lower, only with a locking function and with additional fixation with a latch. Depends on the material and the number of combinations of the secret:

• reliability and the possibility of resistance to mechanical stress;
• wear resistance;
• key matching is not allowed.

The larva of the door lock is made in three levels of secrecy:

• low - from 100 to 10 thousand combinations. It is made of low-strength materials with a simple key profile;
• medium - from 5 to 50 thousand combinations. It features a complex opening mechanism, but the quality of workmanship is not always up to par;
• the highest - from 100 thousand combinations to infinity. The materials of manufacture are of high quality, and the assembly accuracy is high.

Each of the locking mechanisms has its own design features, which determine the process and the possibility of replacing its larvae.

Cylinder locks

A similar design of castles appeared in the middle of the 19th century. Due to the simplicity and ease of use, cylinder mechanisms quickly became widespread and are currently the most in demand.

Cylinder locking mechanisms are manufactured to the DIN European standard or the RIM standard, which is now produced in small quantities. Larvae from different manufacturers of the DIN standard are practically interchangeable. Their choice depends on the thickness of the door leaf and the location of the fixing screw in relation to the inner and outer plane of the door.

Cylinders can be subdivided:

• to the turnkey system. From the inside, the door opens with a rotary knob (turntable), which can be easily felt in the dark in case of an emergency or when the room is filled with smoke during a fire. Such a larva for a door lock has a movable cam that transmits movement to the crossbars. As a rule, its position requires adjustment in place;
• to the key-to-key system. The door leaf opens from two sides with a key. Such a secret is convenient when it is necessary to lock the door so that children or sick old people do not open it from the inside. In addition, the internal key inserted into the keyhole can be used as additional protection. It will be impossible to open the door from outside;
• for a half cylinder. The door can only be opened from the outside. A semi-cylinder is installed on the doors in rooms where there is no possibility of people being. These can be small utility rooms or special buildings, for example, an armory;
• on a gear mechanism. The transmission of movement from the key to the bolt occurs more smoothly through the gear, the number of teeth of which depends on the model and manufacturer.

It should be noted that the process of replacing such a larva with a gear is complicated, and only a specialist can help in this matter. To install a new cylinder, it is necessary to dismantle the lock with a similar mechanism as a whole.

RIM standard cylinders are not as common on sale as in Soviet times, and modern mechanisms from European manufacturers are not very popular. In this regard, secrets for them are quite difficult to find. Their design resembles a half-cylinder of the DIN standard, with a difference in the method of fastening - the models in question are overhead.

Do-it-yourself cylinder replacement

You can remove the unnecessary larva of the door lock, and then put a new one in its place, on your own. The process itself will take 15-20 minutes, no more. And from the tools you will need:

• construction roulette;
• crosshead screwdriver.

First you need to find a screw that performs the function of fastening the larva in the general lock mechanism. As a rule, it is located on the lock bar at the end of the door leaf. Its location can be symmetrical and asymmetrical with respect to the thickness of the door, depending on the model and manufacturer of the locking mechanism. Turning the screwdriver counterclockwise, the screw is completely unscrewed, and the larva is removed.

If the cylinder began to move, but continues to “sit” in the socket, it is necessary to insert the key into the larva and turn it a few degrees in a clockwise direction.

Now you should pull the mechanism “toward yourself” or push it from the opposite side. The cylinder will easily come out of its seat. The fact is that a movable cam, or a flag present in its design, can interfere with the release of the larva, and turning the key will hide the cam in the body of the cylinder.

It is necessary to measure the total thickness of the door leaf together with upholstery or insulation, in case additional door lining was made. In the absence of any changes, you can focus on the dimensions of the removed cylinder, which, of course, is easier. In order to determine which particular door lock cylinder you need to purchase, you also need to measure the diameter of the removed larva.

Don't forget the location of the fixing screw! It can be located both in the middle of the butt, and located closer to one of its sides. Moreover, with an asymmetric position, it should be remembered which of the distances is smaller - to the outer or to the inner surface of the door.

It would be more correct when buying a larva for a lock to take the removed cylinder with you. But if this is not possible, you should focus on accurate measurements. The color of the new mechanism will also play an important role in the choice, otherwise it will not look aesthetically pleasing on the door leaf.

The purchased cylinder is installed in place of the previous larva and secured with a screw. The main thing here is to clearly get into the hole intended for its fasteners. A slight movement of the lock in the plane of the lock and its simultaneous baiting on the fastener will help to cope with this task. The key must be locked in the closed position. After that, the lock is checked for operability, first with the door open, and then with the door closed.

The opening and closing of the lock should be smooth and silent.

Disc locks

The main difference between these mechanisms and other cylinder locks is their design: instead of pins, or pins, there are movable disks that line up when the locking mechanism is opened at a certain angle. The key has a semicircular section with cuts located on it, corresponding to the position of the disks.

A design feature of the disk lock larva is the possibility of replacing it only with a “related” cylinder. But its purchase, at present, is difficult due to the fact that it is quite difficult to find a larva for a disk lock. Therefore, the best option would be to completely replace the locking mechanism.

cross locks

In such designs of locks, pins are used, which line up on four faces inside the larva when the key is turned. Phillips cylinders have many combinations, but the lock can be easily opened with a Phillips screwdriver.

pin locks

The larvae of pin cylinder locks are produced for two types of keys:

• English;
• perforated.

In the first case, the lock is not particularly reliable, and the second can only be opened by drilling the cylinder or knocking it out, which is quite difficult and time consuming. The lock core is replaced using the technology described above.

Particularly difficult locks

Manufacturers are constantly working on improving the locks, primarily on their locks. Modern technologies make it possible to make unique mechanisms that are quite reliable and durable. By purchasing high-quality products from world-famous brands, you can avoid the procedure for replacing a door lock cylinder. But this need may arise if the key is lost by one of the household members or office workers.

In particularly complex locking mechanisms, the following are used:

• armor inserts;
• titanium case;
• over a million combinations;
• refractory metal pins;
• floating elements on the key.

It is impossible to pick up the key to such a lock, but it is quite possible to replace the larva. True, it will cost quite a lot.

It seems to many that replacement is a difficult and special process that only a specialist can handle, but in fact, anyone can perform this operation on their own at home. For this reason, knowing how to change grubs is very helpful. So next time you won’t have to wait for repairmen who will fix the problem, but you can start working on the lock yourself. The main thing is that not the entire structure is damaged, and only the core requires replacement, with which a person will need to work.

When replacement is required

It often happens that the lock breaks at the most inopportune moment, and it is simply impossible to leave and leave the door open, because then all the material values ​​will be freely available to third parties. The key may not turn, or vice versa, pass and not start the locking mechanism. In either of these cases, the malfunction is caused due to damage to the door lock cylinder.

Reasons why this might be necessary:

• due to wear of the cylinder, which often happens, therefore, you should try to constantly check the condition of the lock of the entrance metal door, because the mechanisms cannot last forever;
• after trying to disassemble the lock, sometimes it breaks;
• if you hit the castle, then this will also not bring anything good;
• when trying to break or open without a key if it is lost.

Due to the above reasons, there is a problem with the lock of the metal door, which must be solved by replacing the lock, otherwise you will have to purchase a new mechanism. If you make a replacement yourself, you will not have to pay for a new lock, redo the connectors for a new security measure. In addition, you do not need to pay for the work of a specialist. But to fix some systems, you will have to work hard, although most are not so difficult to work with.

Types of mechanisms

Replacing the door lock cylinder will depend on which metal door lock you have to work on.

• Cylinder. This type of lock mechanism can be found in any home, because it is the most popular among all. He earned his fame and prevalence due to the fact that it cannot be hacked. The cylinder locks themselves are also divided into several types: half-cylinder, gear, key-key and key-turntable.

Everything except the gear is suitable for parsing at home. The gear is difficult due to its design, which the average person cannot put back together unless they are lucky.

• Level lock is not easy to replace, it is best to refer to the instructions, it should say how you can replace the larva on this model. Although, by and large, a lever lock is disassembled in almost the same way as a cylinder lock, only the lining, handle and deadbolt are still removed.
• pin. Already a less common mechanism that could not gain enough popularity due to its weakness against robbers, because it is easy enough to hack. But there is one branch of pin locks, perforated - they are still found, because they can somehow protect the room from outsiders. It can also be disassembled and repaired by yourself.
• Disk. The name should already speak for itself - discs are used here, and not the usual pins and pins. The easiest way is to simply change such a lock for a new one, because parts for disk types are almost impossible to find due to the structural features.
• cruciform. It is also not advisable to repair it, because not only is it easy to break into, but in order to get to the core of the lock, you will have to disassemble it completely.
• Special castles. The name should immediately indicate that they are unique, respectively, and very complex. Replacing the lock cylinder of such a complex mechanism on your own is a risky business, so it is better to leave the work with them to professionals.

What to look for when buying a new larva

The most important thing is the size, so that it is identical in size to the one that broke. It is best to bring the original larva to the store, but if this is not possible, then you can take measurements of the cylinder. According to them, the seller will already be able to suggest a suitable option. Also, do not forget about the manufacturer of the lock for the entrance metal door, because if this is a common brand, then most likely the store will have a part that is ideal for the lock. If harmony is important to the buyer, then you need to pay attention to the color scheme so that it can be combined with the rest of the metal door. It is also worth buying a larva if your lever lock is broken.

It is worth choosing larvae of the middle price category and above. The fact is that cheap analogues will not be a long-term acquisition. In addition, due to the cost of the material from which they are made, they are quite easy to hack. It is better to play it safe and purchase the type of cylinder that will be more expensive.

The replacement of the larva

It is best to consider this operation using the example of a cylinder door lock, which is the most common. So it all starts with removing iron grub from a metal door. The advantages of the cylinder type also lie in the fact that for this operation you do not have to completely remove the lock. All that is needed is to unscrew the screw at the end of the metal door lock. Next, you need to press on the cylinder, and then completely pull it out.

The whole process is detailed in the following video:

The new larva must be completely identical in size to the original part. Otherwise, the operation will not be carried out correctly. The new part is placed in place of the old larva. It also needs to be pressed, and then secured with a screw. The process is completely the reverse of extraction. Final stage- work test. If all is well, then the lock will work like new.

The closest type of locks according to the method of replacing the larva is pin. Here the process is completely identical, with the exception of some details that complicate the extraction itself. But the cruciform and disc types of locks are best to just change. Their repair may require much more effort and energy than it's worth.

It is generally better not to mess with special locks, because of the complexity of the mechanism, an unprepared person will simply get lost in the whole multitude of options for action. In addition, each of them is individual, because it costs a lot of money.

So the operation to replace the cylinder is not so complicated, all that is needed is patience, and also follow the instructions in order to change it qualitatively.

Each of us uses locks every day. Starting with the fact that we leave the house and close the door behind us, and ending with locking the car doors, and simply locking bags and briefcases with code mechanisms. Our life is completely intertwined with doors and secret locks. And, of course, sooner or later we are faced with a situation where the lock fails. This is a natural process because everything in this world grows old and begins to break down. And if this happens, repair or a complete replacement of the mechanism is necessary.

Of course, there are completely different cases, but which are also associated with the locks of the front doors. So, for example, very often the question arises of replacing keys with an already existing secret mechanism. This may be due to the loss of keys by one of the family members, the need to restrict access to the premises to people who already have keys, and simply to the reason for the poor performance of their functions by the lock cylinder (jamming, poor rotation, etc.).

It is precisely in this case that the need arises for lock cylinder replacement , which we will now consider.

What is a lock larva?

This is exactly the part with a secret mechanism into which the key is inserted, and which checks the compliance of our key with this mechanism.

The procedure itself lock cylinder replacement it is much easier to replace the entire lock in the door, because this is practically the first operation in the complete replacement of the locking mechanism. And in total it will not take more than 10 minutes.

Replacing the mortise lock in the door

We arm ourselves with a Phillips screwdriver and begin the repair procedure. First of all, we open the door and from the end we find a bolt in the end plate, which secures larva(it is located approximately in the middle of the bar). Inserting a screwdriver into it and turning it counterclockwise, unscrew it, as shown in the photo below.

Completely remove the bolt from the hole. The larva, which we are changing, has begun to move, but is not pulled out of its nest. To understand why this happens, look at the photo below.

The photo on the left shows the secret mechanism with the flag extended, as it is located in the locking mechanism in the normal state with the keys removed. The right photo shows an already recessed flag. So this extended flag does not allow our larva to leave the nest when the mounting bolt is unscrewed.

You can remove the flag inside only by inserting the key and turning it in the larva by 10-15 degrees clockwise. Thus, we insert the key, turn it 10-15 degrees and, pulling it away from the door (as shown in the photo below), or pressing from the back of the door on secret mechanism, take it out of its nest.

That's it, this is the first stage of the operation for lock cylinder replacement completed. The larva is in your hands, i.e. now you have a sample that you need to buy.

We go to the store and buy a new one. larva.

When choosing, you need to pay attention to:

1. To choose the right size larvae both in length and diameter. They come in different lengths (since the thickness of the doors is different for everyone). The diameter may also differ if it is an imported manufacturer.
2. According to the configuration of the larva, you need to look at the location of the mounting hole (where we unscrewed the mounting bolt from). The distance from the end of the larva to the hole on the new larva should not be less than the same distance on the old locking larva, both on one side and on the other. (It can only be equal to or greater than. More is allowed, but then secret mechanism you will have a little more peeking out of the castle than the old model).
3. Larvae are equipped with a different number of keys (choose as many as you need, no matter what happens after the purchase, that someone from the family members will not get the key).
4. They come with key grooves on both sides (as in our example), and there are: on the one hand, the key groove is the street side of the lock, and on the other side there can be a “turntable lamb” - to open the lock from the inside without a key.
5. They also differ in the shape of the keys (because there are a huge variety of keys: from simple flat "English" keys to complex perforated or laser ones.

And the last:

6. Pay attention to the color of the selected larva, it should be in harmony with the color of your castle.

If a situation arises that it is not possible to take the mechanism with you (for example, because it is at the front door and it is undesirable to leave the house open), then we simply take measurements from our larva (mainly length, diameter, distance from the end to the mounting hole and manufacturer's firm (in our case, "Bulat")). We visually remember its color and insert it back before acquiring a new part.

After we decided and bought a new larva All that remains is to put it back in its place.

Installation operations are carried out in the reverse order of extraction. The biggest difficulty can only arise with the fixing bolt getting into the hole. A slight movement of the larva across the plane of the lock with the simultaneous baiting of the fixing bolt will help to cope with this problem.

Health check

After lock cylinder replacement be sure to test the operation of the lock on the open door both from the inside and from the outside of the door. If everything is done correctly, the key should turn freely in the lock. The lock should open and close freely, the crossbar should be free to leave the lock and return back. The lock should not make any squeaking and creaking sounds.

If everything works well, you can try opening and closing the locking mechanism in the closed door position.

That's the way door lock replacement do-it-yourself is simple and easy.

Good luck to everyone and less troublesome repairs.