DIY door locks repair

Recommendation points

• General device of a mechanical door lock
• Why do locks break for interior doors
• Problems with the door leaf or loot
• Locking mechanism dusty or rusty
• Worn or broken internal elements of the lock
• Mortise door lock. Repair and maintenance
• Handle lock for interior doors. Repair and maintenance

The lock is a simple mechanism that consists of a set of metal rod plates and a series of springs. Bending or disengaging each of these elements will cause the lock to malfunction, which can be easily corrected on your own. How to repair the castle with your own hands, our article will tell.

General device of a mechanical door lock

The appearance of door locks can vary depending on the requirements for their size and design, but at the same time, its internal structure remains virtually unchanged.

Regardless of the manufacturer, the lock will always be equipped with a bolt (bolt) with a mechanism for its movement and a key recognition mechanism, depending on its shape, it can be called a secret, a larva or a cylinder. Without these components, the castle will cease to perform its functions. For ease of use, a handle and a latch-bolt (tongue) can be built into the mechanism, allowing you to close or open the door, to fix it in a closed state.

Why do locks break for interior doors

Manufacturers can use mild steel, copper and aluminum alloys for the manufacture of levers of the mechanism, which are not able to withstand increased loads for a long time. That is why the main reasons for the failure of the lock mechanism are:

1. Problems with the door leaf or loot.
2. Locking mechanism dusty or rusty.
3. Worn or broken internal elements of the lock.

Consider the impact of each of the negative factors on the door lock.

Problems with the door leaf or loot

Both interior and exterior doors, no matter what material they are made of, can deform over time. Any change in the geometry of the door causes displacement of the lock bolts in relation to the striker..

The mechanism for moving the crossbars is not intended to overcome the friction arising from the contact between the bolt and the bar. The additional load arising in this case is distributed to all elements of the lock and becomes the cause of the breakdown of the weakest link in the system – the secret.

Somewhat less often for this reason, the crossbars and the mechanism for their movement break..

Locking mechanism dusty or rusty

Operation of a mechanical lock in highly dusty rooms, and not carried out timely maintenance leads to an increase in internal resistance between the moving parts of the mechanism. If this problem is ignored for a long time, it may cause the lock to jam or break. This factor is especially dangerous for models in which additional locking rods are installed..

No less problems for the operation of the lock are caused by the rust that has appeared on the internal elements of the lock. Only regular cleaning and lubrication of the mechanism can significantly extend the life of the lock and avoid unforeseen breakdowns..

Worn or broken internal elements of the lock

Even with timely maintenance, the internal elements of the lock experience significant stress and may break. After replacing a failed part, there is a high probability that the lock will serve for many more years..

Mortise door lock. Repair and maintenance

Let’s consider in detail the most common design among all types of locks, used in both wooden and metal doors..

The mortise lock is highly reliable due to the simplicity of the mechanism. The most difficult part in its design is the cylinder mechanism, which is easy to change. Its replacement is carried out when the key is wedged, the mechanism is periodically blocked, the keys are lost, etc..

Checking the performance of any locks and their repair:

1. Open the door.
2. Check the operation of the lock for backlash and jamming.
3. Compare the operation of the lock with the door open and closed, if the mechanism works worse in the closed state (sticks, does not close, moves tighter), check the striker plates for friction with the bolt, change the striker plate geometry to eliminate friction.
4. Remove the lock.
5. Open the protective cover of the mechanism.
6. Take a picture of the mechanism inside.
7. Clean the mechanism from dust, rust, old grease.
8. Flush the lock with kerosene if necessary.
9. Check the integrity of the springs, the condition of the deadbolt movement mechanism.
10. Check the operation of the secret without a lock, replace it if necessary.
11. Assemble the castle according to the photo.
12. Install the lock on the seat.
13. With the door open, check the operation of the lock mechanism.
14. Check the operation of the lock mechanism on a closed door.

In order to avoid breakage of the lock at the most unexpected moment, at the first signs of malfunction, it is necessary to do its maintenance. In its process, it is possible to identify problem nodes and eliminate the reason why the lock has become “worse to work”. In addition, regular maintenance carried out for the home door every few years can significantly extend the life of the lock..

During the check, special attention must be paid to the condition of the mechanism springs, if necessary, return them to mesh with the seats, and in case of breakdown, replace them. Check each lock mechanism separately, identify places of increased friction and components that do not perform their functions, restore the operation of the mechanism (put the thrust in the seat, replace the plastic bushings, align the bent ones, replace the worn ones).

To carry out maintenance or repair of the mortise lock, you need to remove the mechanism from the door.

1.Use the hexagon to unscrew the screw securing the outer door handle to the square.

2. Unscrew the bolt from the cylinder block

3. Pull the secret towards you. At the moment when resistance appears, turn the key in the keyhole so that the secret tongue disengages from the body and the lock mechanism.

4. Unscrew and remove the fixing handle of the lock bolts.

5. Remove the handles themselves and the square.

6. Unscrew the screws fixing the case of the mortise lock and remove it.

7. Clean the seat of the lock from dust and chips.

8. Check the integrity of the handle mechanism, clean it from dust and lubricate. In this case, special attention should be paid to the springs of the return mechanism and limiters..

9. Clean from contamination and check the operation of the lock cylinder (secret).

10. If the key is broken in it, remove its fragments with tweezers.

11. Lubricate the slave cylinder.

12. Unscrew the bolts fixing the protective housing of the lock and remove the top cover.

13. Clean the inside of the lock from dust and rust.

14. Check the condition of the springs and steel rods..

15. Lubricate moving parts..

16. Assemble the mechanism for moving the bolt and latch, check its operation.

17. Install the lock in the seat in the reverse order shown..

18. Check the operation of the lock with an open and then a closed door.

19. If necessary, adjust the clearances in the strike plate.

Handle lock for interior doors. Repair and maintenance

Due to the optimal ratio of cost and reliability, the handle-lock (handle-knob) takes first place in popularity among locks for interior doors. The unique but simple design of the lock handle is easy to repair. Most often, the return springs and the latch mechanism break in it, the repair of the lock handle in most cases is limited to the return to its seat of the disengaged springs and rods.

To carry out repairs or maintenance, you will need to remove the knobs (handles), for which:

1. On the body of the decorative cover we find a special hole.

2. Turning the handle, move the spring hook directly under the slot.

3.Using a special key or a clock screwdriver, press the spring clip and at the same time pull the handle off the mechanism. From the side of the latch, remove the decorative cover, for which we simply pry it with a screwdriver. Unscrew the screws connecting the inner and outer parts of the lock

4. We take out the inner and then the outer part of the lock.

5. Unscrew the two screws that hold the latch and take it out.

After the dismantling of all parts of the lock is completed, we check the integrity of the mechanical elements, clean the mechanism from dust and dirt, lubricate the working parts of the mechanism.

Pay particular attention to cleaning and lubricating the latch mechanism.

The integrity of the return and locking mechanism of the handle.

After checking and repairing, the handle is installed in its seat. Checking the operation of the castle.

Regular maintenance of the door lock, lubrication and periodic performance check will be the best prophylaxis, allowing you to timely prevent the failure of the locking mechanism, which will save you time and money and avoid emergency door opening by breaking the lock.