Repair Of Door Locks: What Malfunctions You Can Fix Yourself And How To Do It Correctly

2024 Author: Bailey Albertson | [email protected]. Last modified: 2023-12-17 12:53

Repair of door locks

Each house has a door with an installed lock. And like any technique, locks sometimes break. To prevent the problem from being caught by surprise, you must carefully monitor the state of the locking mechanism. Otherwise, one day you may find yourself on the street, and the "enraged" castle will not let you into your own house.

Content

• 1 Types of door locks

• 2 Causes of door locks breakage and how to fix them

  • 2.1 Troubleshooting Algorithm
  • 2.2 The problem in the counter part of the castle
  • 2.3 Dustiness of the lock mechanism and rust
  • 2.4 Breakage of the secret mechanism
  • 2.5 Broken lock case

• 3 Replacing the door lock

  • 3.1 Required tool
  • 3.2 Replacing the lever lock

  • 3.3 Replacing the lock cylinder

    3.3.1 Video: how to replace the lock on the front door

• 4 Reviews

Types of door locks

Locking devices on doors are divided into several categories. They are classified by:

• type of attachment;
• secret insert mechanism (larva);
• appointment.

Locks for interior doors are considered a separate type, since their task includes not so much a locking function as a locking function. Lightweight locks designed to hold the door leaf in the closed position are distinguished by their ergonomic design and small dimensions.

Locks for interior doors are compact

The type of fastening of the lock is the sign that catches the eye in the first place. There are three main types of locks:

• hinged (used for utility, industrial and warehouse premises);

  

  The shape and size of the padlock is selected depending on the shape of the locking bows on the doors

• invoices (intended for any type of door, easy to install);

  

  Most often, a patch lock is used as an additional locking device on the front door.

• mortise (the most reliable and common type, which is used for almost any entrance and interior doors).

  

  The case of the mortise lock is hidden inside the door leaf

By appointment, locks are:

• locking. Mostly used for entrance metal doors. In their design, there are no spring-loaded (halyard) tongues that hold the door leaf in a closed position;
• locking and fixing. They are considered more versatile and are widely used for both external and internal doors. Structurally, such locks are distinguished by the presence of a movable handle, with the help of which the latch is controlled. When you press the handle, the tongue is hidden in the recess and the fixation is removed from the door leaf.

The heart of the lock is an insert with a key recognition mechanism, the so-called lock or cylinder. There are several types of such devices, differing in design.

1. Cylinder (or English) larva. The principle of operation is based on the fact that a cylinder with a unique combination of small protrusions is installed inside the lock, which can only be turned with an appropriate key.

   

   Cylinder head is used for all types of locks - padlocks, overhead and mortise

2. Lever lock is a set of metal plates (levers) that can be combined only with a key with notches. Such a lock cannot be opened with a master key. But if you lose the key, you will have to completely change the secret part.

   

   It will be very difficult to force open a lever lock without a key.

3. Pin locks. Based on the principle of matching a combination of spring loaded pins with grooves on the key.

   

   The key turns in the lock only when the combination of pins matches the grooves on the key

4. Disc larvae. Encoding is done using metal discs. When trying to break through the keyhole, the disks of the secret device cannot be ordered (they will rotate with the drill), which is the key to security.

   

   Disc code mechanism cannot be drilled out when broken

5. Electromechanical decoders. They are considered the most advanced security systems. The mechanism is driven by electrical impulses. Unlocked with a plastic card or a remote control key fob.

   

   The closing valve is driven by an electric current in the solenoid

6. Code devices. They do not have a key; instead, a code selection variator is installed on the case.

   

   The "key" to the combination lock is always in the owner's head

"Invisible" locks are powered both from the network and from independent power sources

Causes of door locks breakage and how to fix them

The following symptoms indicate a problem with the lock:

• when the key is turned in the keyhole, clicks are heard, but the locking bolt does not move out of the recess;
• the key does not enter or leave the key slot;
• the mechanism jams during operation, idle turns of the key.

If these symptoms are found, it is urgently necessary, without postponing, to call the master or to fix the lock yourself

Here you need to immediately make a reservation that it is not recommended to repair electronic and lever locks on your own. The first ones are programmed so that if the electronics are damaged, the blocking can be triggered and the lock will jam. Lever mechanisms, especially of a complex design with an increased security function, are often unique. There are no spare parts on sale, a damaged plate is changed only at the manufacturer. This is especially true for expensive locks made for custom-made doors.

Before starting the repair yourself, you need to accurately determine the type of lock. There are many resources on which, by the shape and size of the key, you can find out the type and design of the lock mechanism. There are also detailed descriptions of the internal structure of the gate part.

Troubleshooting Algorithm

Naturally, in order to undertake the repair of the castle, you need at least in general terms to imagine its structure. Fortunately, most locks have approximately the same principle of operation. Almost all of them consist of:

• housing;
• secret code mechanism;
• the mechanical part - the power transmission system from the key to the crossbar (locking tongue).

When determining the cause of a breakdown, external factors must also be taken into account. The operation of the lock largely depends on the general condition of the door and, first of all, on the condition of the hinges.

Before disassembling the lock and opening its case, you need to carefully examine the position of the door leaf. If the sash is skewed, rubbing against the door frame, metal creaking, grinding, etc., this indicates a malfunction of the door hinges. And the repair should start with them.

Adjustable hinges are adjusted with a hex wrench

The problem is in the mating part of the castle

Often the reason for the incorrect operation of the lock is the failure of the locking bolt to fall into the counterpart on the door frame. There are two ways out in this situation:

• return the door leaf to its original position by tightening or replacing the hinges;
• move (or bore with a file) the counterpart under the new position of the crossbars.

The first method can cancel the repair of the castle, the second - postpone.

The crossbars may not fall into the counterpart of the lock due to the fact that the door is twisted due to the incorrect position of the hinges

The problem with the crossbars not falling into the counter part of the lock can be associated not only with the hinges. Another external factor that directly affects the health of the locking mechanism is the condition of the door leaf. Wooden doors are prone to deformation over time, wood cracks or swells from excessive moisture. This leads to a change in the geometry of the sash and displacement of the lock relative to the frame. Even a slight friction between the deadbolt and its counterpart leads to the fact that more and more force is required to open the lock with the key. As a result, the larva, which is made of soft metal alloys, breaks down very soon.

Dustiness of the lock mechanism and rust

There are a number of external reasons that affect the operation of all locks without exception. These include:

• high humidity, as a result of which rust forms inside the mechanism;
• excessive dustiness (fine dust particles, settling on the lubricant, form hard layers inside the structure).

The listed reasons eventually lead to the breakdown of the lock. It is possible to reduce the influence of adverse factors with the help of regular preventive maintenance, lubrication and timely replacement of damaged parts.

Experienced craftsmen advise at least once every two years to carry out door locks prevention

There are also reasons that are related to damage inside the castle. The reasons are different, ranging from mechanical damage and ending with a factory defect. One of the reasons is the natural wear and tear of rubbing parts. If the lock is made by an unscrupulous manufacturer, and important structural components are replaced with plastic ones, the mechanism will not differ in its long service life.

Breakage of the secret mechanism

To avoid corrosion, larvae are usually made from non-ferrous metals or their alloys. For example, aluminum is not susceptible to rusting, but it is also a relatively soft material. If a steel nail is inserted into the keyhole of an English lock, the delicate locking mechanism will be damaged and will not function normally. In this case, the larva will have to be replaced. The same situation is with almost all models of door locks (with the exception of some old-style hinged types). A good lock made of quality stainless steel has a high cost. Inexpensive locks are relatively short-lived.

Larvae of inexpensive locks are usually made from non-ferrous metals or their alloys.

Breakage of the lock case

In overhead and padlocks, body defects are visible immediately and well. They look like chips, cracks or deformations of individual parts. But with a mortise lock, things are not so simple. The body is located inside the door leaf, and in order to inspect it and determine its integrity, it is necessary to remove the lock from the installation slot. There are numerous cases when the lock ceases to function properly only due to the fact that the fixing screws are overtightened during assembly. An over-tightened screw deforms the body, which leads to malfunction of the lock as a whole. From the inside, mechanisms (levers and springs) are attached to the walls of the case, therefore, when assembling, you should follow the manufacturer's recommendations, and not try to tighten the screws as much as possible.

Particular attention in this regard should be paid to overhead locks made of duralumin. The casing of such devices is not designed for mechanical loads, and duralumin is a brittle metal. An extra turn of the fastening screw can chip and destroy the case.

The nuts on the four mounting bolts must not be overtightened, since duralumin is highly fragile

Repair of any kind of castle consists in restoring its original functions. To do this, you need to find the cause of the breakdown and replace the damaged part. In this case, it is also advisable to detect the source of the malfunction and, if possible, eliminate it (adjust the hinges, adjust the strike plate, etc.).

In practice, only a small group of locks can be repaired. By virtue of their specificity, padlocks are most often non-separable (the body is cast, welded or blind riveted). Overhead locks can be repaired, if the breakdown lies in the larva - a replacement is made. Mortise locks rarely break, mainly as a result of malicious acts. In almost any case, it is better to change the lock. It is easier (for the layperson) and more reliable from a security point of view.

Replacing the door lock

The simplest and most common operation to repair a lock is to replace it. Entrance doors are equipped with at least two locks. Therefore, when replacing one of them, they use the other.

Required tool

The lockmaker's arsenal should always include:

• screwdrivers with different shapes and sizes of slots;

  

  The universal screwdriver contains bits with different slots

• tweezers;
• metal files and files;
• pliers (pliers or round nose pliers);

• lubricants and compounds (WD-40, graphite grease);

  

  WD-40 Aerosol is a low density, general purpose lubricant

• brush (old toothbrush);
• rags (pieces of soft cloth).

Renovations require good lighting and a comfortable, uncluttered desk. Sometimes a magnifying glass and a magnet are useful for collecting small parts.

Consider the procedure for replacing locks.

Replacing the lever lock

To replace a plate (lever) lock, first of all, you need to remove the mechanism from the cavity in the door leaf. For this:

1. Using the key, set the lock to the "open" position. The locking bolts are hidden inside the door leaf.

2. We unscrew the overhead rings on the latches (if any). We dismantle the door handles from the inside and outside.

   

   The pads are fixed with a hex key from the bottom or from the side

3. After removing the decorative overlays, unscrew the screws securing the valve drive and the handle.

   

   The latches and handles are removed by unscrewing the screws and mounting screws

4. We unscrew the screws located at the end of the door.

   

   As a rule, the lock is fastened with screws on the side of the door, which can be from two to six

5. We remove the tetrahedral (sometimes triangular) rod that connects the door handles.

   

   The bar connecting the inner and outer door handles is pulled inward

6. We remove the lock case from the doors, carefully prying it with a screwdriver by the flange.

After that, it remains to find exactly the same model of the lock and assemble in the reverse order.

Replacing the lock cylinder

The cylinder lock can only be repaired by replacing the secret cylinder, which itself is non-separable. The cost of the larva is small, and the work takes only a few minutes.

1. All fittings are removed from the doors that prevent access to the larva. These are, as a rule, door handles, protective and decorative linings. Dismantling is carried out by unscrewing the fixing screws.

   

   The protective strip is removed by unscrewing the screws

2. In the end part of the door (on the lock bar), a screw is found that fixes the larva. It is usually located at the same level as the larva (horizontally). Using a screwdriver, the screw is completely unscrewed and removed. At the same time, the larva is released, it can be pulled out to the inner side of the door.

   

   The larva rests on one screw, the head of which extends onto the lock plate of the door leaf

3. To extract the "secret" you need to insert the key into the lock and make a half turn. If done correctly, the larva will freely fall out of the nest.
4. Having picked up a new larva (in shape and size), they are installed in the reverse order.

Video: how to replace the lock on the front door

Reviews

Armed with a simple tool and basic knowledge about the device, anyone is able to repair or at least replace the lock in their own door. But if for some reason there is no self-confidence, you can always turn to professionals. For relatively little money, they will repair your door lock and give you a written guarantee for at least six months.