How to change the larva in the door lock. How to change the larva in the door lock without a master
There is no doubt about the reliability of the entrance metal door for a long time, it is a solid structure that successfully performs its safety function. But whatever one may say, without a quality lock, the chances of resisting breaking and entering are zero.
Not only the safety of property, but also the comfort of your family depends on its quality and cost. The basis of security is the main detail of the design of the lock - the larva, and the key to it.
A cylinder is a device that provides the transfer of force from the key to the door lock mechanism and at the same time a secret element. In simple words: the cylinder is fixed inside or outside the body, and can only turn if the key is inserted into the hole. It is the most precise mechanics of the cylinder that is responsible for recognition according to the “friend/foe” principle. In the people, such a mechanism was called "larva", as it has an elongated shape. In a professional environment, this is a cylinder secrecy mechanism (CMS).
It is not difficult to guess that the cylinder or larva is the basis of precisely the cylinder (“English”) locks. They are quite popular today due to their ease of use and maintenance. The key is small, it does not require much physical effort to open the door, but the main plus is that in case of a breakdown or other reasons, it is enough to replace only the larva of the mechanism.
Why change the lock?
There are not many reasons to think about replacing the old castle, but they are. It often happens that the key simply starts to stick in the cylinder, which can occur as a result of damage to the device by a foreign object or untimely maintenance of the product. The same reason can be the loss of a key, moving to a new place of residence, and so on.
But before you hastily purchase and install a new lock, analyze the situation, it is possible to drill, disassemble and replace the front door lock cylinder with a new one will be more than enough. Having spent money on a new and high-quality device, you will still save on buying a whole mechanism.
Moreover, CMS in most cases is subject to the European standard DIN (Europrofile), which indicates versatility and interchangeability in the mechanisms of manufacturers.
In order not to get into trouble, carefully determine the company and brand of your product, otherwise you will realize that you are the owner of a Chinese or Soviet mechanism when the money is already wasted.
Replacing the mechanism in this case will not be possible.
Types of lock cylinders
There are many types of larvae for locks, we will consider the typology of those that are used everywhere.
Locking type:
- Key/key (double-sided).
External and internal locking of metal doors occurs with a key. Most often, if a key is inserted into the larva from the inside, it will be impossible to open the door from the outside. - Key / turntable (one-sided).
From the inside of the room, the door opens and closes using a turntable. Most often they are not equipped with a “dead point” system - the key opens the lock in any position of the turntable.
The length of the cylinder is determined by the width of the front door leaf. In the middle of the cylinder there is a rotary cam, the width of which is always 10 mm.
Cylinder displacement for door locks is measured from the middle of the cam:
- equilateral cylinder - two extreme parts are the same in length;
- versatile cylinder - different lengths of two parts.
Properly selected in length, the product will not protrude much beyond the plane of the door leaf.
To choose the right part for changing the mechanism, some requirements should be considered:
- secrecy - the number of combinations;
- security - the degree of resistance to hacking, which depends on the service life of the CMS.
Instructions for changing the cylinder
Replacing the core in the front door lock is a cheaper and more rational way to repair than replacing the entire product. Moreover, changing the whole lock in a metal door is an expensive pleasure.
Replacing the main part of the structure does not take much time and does not require a whole set of various tools.
You only need 4 things: a tape measure, a screwdriver, a new mechanism and a drill (if you need to drill out the core).
Larva measurement
Before replacing the CMS, it is necessary to determine the thickness of the door leaf and take the dimensions of the lock core to select the cylinder of the desired length. Too long or short length is a design violation.
For correct measurements, the lock cylinder must be removed. It is necessary to unscrew the bolt that fixes the part, and insert the key into the well, to put the lock mechanism in the open state, the cam should come out.
Further, the core of the lock can be easily removed by pressing from the back. But sometimes it happens that it is not possible to get the CMS without difficulty (damaged mechanism or stuck key). The solution to the problem will be a drill. With a drill with a diameter of 10 mm, you need to drill out the core, disassemble it and stick it out.
After the part is in your hands, measure its length, width and diameter. Install the manufacturer and insert the larva into place. Now it's time to purchase a new cylinder and install.
Replacement of the larva
Replacing the old core with a new one is not a difficult process at all.
It is necessary to disassemble the core again if it was installed back after measurements. Next, insert a new larva into the hole, bring the rotary cam to the “closed” position and fasten the bolt. The replacement of the door lock cylinder has been successfully completed.
When purchasing a privacy mechanism, it is not recommended to give preference to the cheapest one. The design of this type is easily hackable, as it is made mainly of brass metal and does not have the proper strength.
In this case, the replacement of the mechanism will not make sense. The best option is to choose a cylinder from a similar manufacturer, if, of course, it meets all operational requirements, then the replacement of the larva will be quick and safe.
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:
- To choose the right size larvae both in length and diameter. They are different lengths(since the thickness of the doors is different for everyone). The diameter may also differ if it is an imported manufacturer.
- 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).
- 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).
- 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.
- 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 the dimensions from our larva (mainly the 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.
Even a very high quality lock can break. The working part breaks, for cylinder locks it is a larva. Another trouble may happen: the key is lost. Or ended up in the hands of strangers, presumably intruders. Dismantling the lock and installing a new one is expensive and energy intensive. It is enough to change the larva. How is a door lock cylinder replaced?
For metal doors
1. Open the door, remove the end plate of the lock.
2. Unscrew the screw in the center of the device.
Video "How to change the larva in the castle with your own hands":
3. Unscrew the cylinder. This can be done with a key (if any). If not, you'll have to drill out.
Attention: imported expensive locks have many protection systems; when trying to drill, you can break the drill. It is recommended to use carbide or invite a professional craftsman.
4. Purchase an identical larva in the store. If the lock model is known, it is better to buy a cylinder before starting the repair.
5. Install the new cylinder in the lock with the key.
6. Fix with a screw.
Video "How to replace the larva in the castle":
7. Replace the end plate.
Replacement in a wooden door is carried out in the same way if the lock is mortise. To repair the overhead lock, you need to remove it and remove the larva.
How to drill a larva
Video "How to drill a lock cylinder":
It may be necessary if the key is lost. You will need a 3-5 mm drill.
2. Insert a wire into the keyhole and open the door.
Video "Replacing the lock cylinder of the front door":
3. If it doesn't come out, drill a second hole at the top of the hole and open the lock with a flathead screwdriver.
Replacing the door lock cylinder is a fairly simple task that anyone can do. The exception is expensive armored doors and high-security locks, in which case it is better to call a specialist.
If the lock on the front door of a house or office is broken, try changing its inner part - the larva. You can do it yourself. How to pull out a faulty mechanism and in what ways you can open a jammed door - read on.
How to extract a larva to pick up a replacement for it
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As a rule, the mechanism does not fail unexpectedly. Having noticed the first signs of a malfunctioning lock, hurry up to replace it in the near future, otherwise at the most inopportune moment you simply won’t be able to get into your home or work. A fairly common reason that the door has stopped opening is the breakdown of the larva. This is a detail of a lock with a secret mechanism where the key is inserted. It looks like a cylinder connected to a mechanism - a set of pins that opens only a key specially made for it. The larva controls the locking mechanism, it is easier to change it than the entire lock.
Lock device
Before purchasing a new part, remove the broken one:
- Unscrew the fixing bolt at the end of the door that holds the lock mechanism in place.
- After inserting the key into the well, turn it 10-15 °.
- Noticing that the special flag of the mechanism no longer protrudes, pull out the larva. This can be done from either side: from the outside, by pulling the key towards you, or from the inside, by pressing on the mechanism. If the larva is equipped with a rotating lamb, pull only in its direction.
Attention! If the larva cannot be obtained, this is probably prevented by decorative pads for the lock. They need to be removed and returned to their place only after the replacement of the part.
How to choose and replace the larva in the door lock. Instruction
Having received a worn-out part in your hands, take measurements in order to buy an identical one. Pay attention to the following parameters of the larva:
- length;
- width;
- diameter.
These specifications vary as doors can be of different thicknesses. In addition, the indicators depend on the manufacturer. It is better to give preference to the firm, the larva of which was already in your castle before. Pay attention to the location of the mounting bolt hole. It should be at the same distance.
The lock
Keep in mind that the larvae differ in the shape of the keys, as well as the number of grooves for them: sometimes 2, and sometimes 1 plus a special lamb, thanks to which the door can be opened from the inside without a key. The color of the larva is also important - it must be in harmony with the entire castle. If possible, take the extracted part with you to choose the same one. Otherwise, rewrite the parameters and select according to measurements.
Advice. Included with the larva may be a different number of keys. Decide how much you need so as not to leave one of the family members without a personal copy.
To install, follow the same steps as when removing the mechanism, but in reverse order:
- Insert the larva into the castle.
- Secure everything with a bolt at the end of the door. If it does not fall into the desired hole, move the larva and screw the part at the same time.
- Check the quality of the installation by opening and closing the door with a key on both sides. It should turn freely, and the lock should not creak.
Attention! First check the operation of the mechanism on the open door. If everything went smoothly, you can test the lock by closing the door.
It is also possible to replace the larva without a key - for example, if it breaks and a part remains inside the lock. To remove the chip, you need to turn the locking mechanism. There are 3 ways to do this:
- get the pins from the larva;
- make a hole with a 3 mm drill under the cylinder;
- having removed the lining from the door, look through the slot where the flag is turned. Drill out the entire body of the lock and remove the larva.
Which option is better to use? This needs to be decided on a case-by-case basis.
If the lock did not wait for timely repairs and let you down, leaving you in front of a locked door, there are several ways out of an unpleasant situation.
Emergency extraction of the lock cylinder
- Try to get into the house through the window. Not suitable for apartments located in high-rise buildings.
- Dismantle the entire structure, together with the frame. To do this, you need to remove the lining around the entire perimeter of the opening, frozen pieces of mounting foam and saw through the places connected by welding with the help of a grinder. To apply this method, you need to have the appropriate tool at hand.
- Also use the "grinder", but only for sawing the castle. This is fast, but in the future it requires the replacement of the entire input structure.
- Call the rescue service or the company that installed the door. It will take time to call and work with specialists, and sometimes you may need documentation confirming your ownership of the house.
There are ways that allow you to open a broken lock with the least loss:
- With a hairpin, paper clip or wire. Break the makeshift lockpick into 2 parts. Insert one into the lock and try to turn it while pushing the pins with the second part. It does not work with all types of mechanisms.
- Screwdriver. Effective for a cross lock. Having unscrewed its top, drill a hole above the keyhole, insert a screwdriver and turn it.
- Drilled out the lock cylinder. Not suitable for those designs that are equipped with powerful armor plates.
Advice. In order for the lock to serve properly, lubricate it regularly, do not insert foreign objects there. Do not slam the door to eliminate the possibility of its deformation or distortion. By following these rules, you will significantly extend the life of the locking mechanism.
How to replace the lock cylinder: video
How to change the lock cylinder with your own hands: photo
Many people ask this question when they encounter the problem of lock jamming when opening and closing it, butnot everyone ends up changing the larva in the castle himself, because there are specialized organizations that can make quick and high-quality repairs of even such a trifle. However, such a trifling task can be solved by everyone.
What is a lock larva?
Almost every day a person is faced with door locks. They exist on the doors of apartments, rooms, cars and in many other places. But no matter how careful they are in their use, once the locks fail. One of the possible problems in the door lock is problems inside the mechanism, which entails the need to change the door cylinder.
What is the larva of the castle? This is part of the lock with a secret mechanism. A key is inserted into it and its compliance is checked when opening and closing the doors. Is it possible to change the larva in the castle by yourself? Yes, and this procedure is not difficult - it will require 10 minutes on the strength.
The process of replacing the lock cylinder
How to change the larva in the door lock? First you need to pick up a Phillips screwdriver and get to work. First, you should find the bolt on the end plate and unscrew it. It is located in the middle of the bar and unscrews counterclockwise. Having completely removed the bolt, you can find that the larva is already moving, but still not pulled out. Then the question arises: "How to replace the larva in the door lock?". The extended flag on the secret mechanism of the lock does not allow to extract it.
In order to “drown” the flag, you will need to insert the key and turn it in the larva 15 degrees clockwise. After that, you can pull the key towards you or press on the secret from the back. After that, the lock cylinder will be removed. Having taken possession of a sample of the larva for your castle, you can proceed to the purchase of a new larva.
Criteria for choosing a new larva for the castle
How to replace the larva in the door lock? Having a sample, you can go to acquire a new larva. Despite its inoperability, you can select a new part from it. When choosing, you need to consider the length and diameter. These characteristics may vary due to the unequal thickness of the doors. Especially often the diameters of the larvae on the doors of foreign production differ.
It is worth paying attention to the mounting hole. It is necessary that the length from the end to the hole of the purchased larvae should match the size of the sample. It is allowed to be more, but in no case less.
How to change the larva on a metal front door? In order for everything to go well when buying a new larva, you must consider the following:
If a situation arises in which it is not possible to leave the door open, then it is necessary to remember all the characteristics of the larva. To be sure, it is better to photograph or sketch it, as well as write down all dimensions.
Installing a new larva
How to replace the core in the lock with your own hands? Having done all of the above, you can proceed to the final stage. The installation operation of the lock occurs in reverse to the removal process. The main difficulty is getting the bolt into the hole. To eliminate this inconvenience, you can move the larva at the same time.
If you have any problems or want to get acquainted visually with the process of replacing the larva, you can resort to the help of the Internet. Having found a video for the queries “how to replace the core of the lock with a video” or “how to change the larva in the door lock with a video”, you can get acquainted in detail with all the intricacies of the process.
Replacement in the absence of a key
Replacing the lock cylinder without a key is also possible. The main action in this case will be the extraction of the broken part by turning the mechanism.
To accomplish this, several options can be proposed, one of which will be the extraction of pins from the larva. If they fall out, the lock will turn without difficulty. Another possible option the larva will be drilled under the cylinder with a 3 mm drill. With a successful outcome, the lock will turn without problems.
Also, a solution to the issue may be the removal of lining from the door. Through the resulting gap, you can see which way the lock cam is turned. Then with a thin drill it will be possible to drill out the entire body of the lock and remove the larva without turning. Which option to use must be determined based on the specific situation.