Servicing Medeco3 Mortise Cylinders

Created: October 15, 2004

The new Medeco3 design incorporates a new servicing procedure that is not present in the Medeco Original or Medeco Biaxial cylinder designs.

Mortise cylinders have always been at the foundation of Medeco's product line. In fact, 10 Series mortise cylinders were the first to roll off the assembly line when Medeco opened its doors and started production in 1968. Although the overall mortise cylinder design has seen very little change...

To access the remainder of this piece of premium content, you must be registered with Locksmith Ledger. Already have an account? Login

Register in seconds by connecting with your preferred Social Network.

Complete the registration form.

First Name Required

Last Name Required

Display Name Required

Email Required

Confirm Email Required

Company Name Required

Job Title Required

Country Required

Zip/Postal Code Required

Forums username Required

Reader (order) Number Optional

What category best describes your business? Required

What category best describes your job title? Required

Figure 28 – With key inserted, press in on the sidebar.
Figure 28 – With key inserted, press in on the sidebar.
igure 27 – While holding your finger over the slider, insert a working key.
igure 27 – While holding your finger over the slider, insert a working key.
Figure 26 – Plug over sidebar, ball bearing toward face.
Figure 26 – Plug over sidebar, ball bearing toward face.
Figure 17 – Rotate shell to insert crescents.
Figure 17 – Rotate shell to insert crescents.
Figure 16 – Disassembled Medeco3 Mortise Cylinder.
Figure 16 – Disassembled Medeco3 Mortise Cylinder.
Figure 15 – Sidebar springs and slider spring are different sizes and are not interchangeable.
Figure 15 – Sidebar springs and slider spring are different sizes and are not interchangeable.

Step 2. Remove Plug. In order to remove the plug, you will need a working key, a key blank, or a probe. If cut keys or key blanks are used, they must contain the proper side bitting for the slider installed in the cylinder. Before the plug can turn, the slider mechanism must be pushed into a position to align its blocking tabs with the gates in the sidebar. Insert your key into the cylinder and turn it 45 degrees. Once the plug is turned, push the plug from the back of the cylinder. You may want to hold your finger over the slider and the sidebar while pulling the plug out. Pull the plug out slowly to prevent losing any of the components.

If a cut key or a key blank is not available, the slider can be pushed inward with a pick or a probe while apply turning force to the plug. This will allow the plug to rotate so that it can be removed from the shell.

Step 3. Remove the Hardened Steel Crescent Inserts. After the plug has been removed, the hardened steel crescent inserts can be removed from the shell. Take the shell, holding it at an angle with the face down, and lightly tap it on a hard surface. The hardened steel crescent inserts will fall out of the shell.

Step 4. Remove the Slider Mechanism from the Plug. The slider mechanism is located on the bottom of the plug on the right-hand side. Taking a small flat blade screwdriver, gently pry up on the slider mechanism to release it from the pocket and to remove it from the plug. You will also need to remove the slider spring.

Step 5. Remove Sidebar from Plug. After the slider mechanism is removed from the plug, the sidebar is ready to come out. Remove the sidebar by turning the plug on its side and tapping gently on table or bench top. The sidebar springs will also need to be removed. The sidebar springs may still be in the sidebar or they may be in the sidebar pocket.

Note that the slider spring and the sidebar springs are of different sizes and are not interchangeable. Also note the location of the springs in the sidebar and the slider. (Figure 15)

The disassembly of the Medeco3 mortise cylinder is complete and the components are now ready to be serviced, cleaned or replaced. Figure 16 shows an exploded view of a disassembly Medeco3 mortise cylinder.

ASSEMBLY OF Medeco3 BIAXIAL Mortise Cylinder
Step 1. Insert Hardened Steel Crescents. (Figures 17 & 18) Place the shell on its side so that you can look down at the slot cut under the face of the shell. Using tweezers, insert the two hardened steel crescents into their respective slots.

Install the crescents with the concave side pointing to the hole for the plug. The convex side of the crescent should be pointing toward the shell. You may notice that the crescent is beveled on one side and flat on the other. This makes no difference during installation. The crescent can be installed with the bevel pointing toward the face or with the flat side toward the face. After the hardened steel crescents have been inserted, position the shell upright to keep the crescents from falling out.

Step 2. Place Slider Spring in Slider. Place the slider spring into the hole locator on the slider (longer spring).

There are two methods to installing the slider in the plug. Both methods are listed below:

Step 3A:

Step 3B. Insert Slider into Plug – Spring Resting on Plug. Install the slider into the plug by inserting the non-spring side of the slider first with the spring resting on the plug. Once the non-spring side is seating in the pocket, the spring can be compressed and lowered into its position in the slider pocket. The slider spring should rest on a ledge along the back side of the pocket. Make sure that the spring is not sitting down below the ledge.

Step 4. Test Slider. After the slider mechanism is installed in the slider pocket, test the slider to make sure it has the proper amount of spring tension by taking a small flat blade screwdriver and pushing the slider mechanism toward the back of the plug. The slider should seat flush with the back side of the pocket. If the slider is not moving smoothly or is not seating flush with the back of the pocket, complete Step 4 of the disassembly instructions and then reinstall the slider and slider springs (Step 3 in reassembly instructions).

Step 5. Install the Sidebar. (Figure 26) After the slider mechanism has been installed, we can install the sidebar. Place the sidebar springs (shorter springs) in the holes located at each end of the sidebar. Place your finger over the slider mechanism in the plug to keep it from falling out. While holding the sidebar horizontally, with the sidebar springs pointing up, place the plug over the top of the sidebar. The plug will have to be rotated so that the sidebar pocket is pointing down. Note that the hardened steel ball bearing in the face of the sidebar should be positioned toward the face of the plug. The sidebar will not go into the plug all the way until a key is inserted.