Replacing an M320 Air Filter
Removing a Front M320 Air Filter
The front air filter, located below the FPC card cage in the front of the chassis, and installs horizontally. The front air filter weighs approximately 2.9 lb (1.3 kg).The air filters are hot-insertable and hot-removable.
To remove the front air filter (see Figure 1):
- Attach an electrostatic discharge (ESD) grounding strap to your bare wrist, and connect the strap to one of the ESD points on the chassis.
- Unwrap any PIC cables from the spools on the cable
management system, and remove the cables from the tray. Arrange the
cables so that they do not block the front of the cable management
system and tray, and secure them with temporary fasteners so that
they are not supporting their own weight as they hang from the connector.

Caution: Do not let fiber-optic cable hang free from the connector. Do not allow fastened loops of cable to dangle, which stresses the cable at the fastening point.
- Simultaneously pull the two releases labeled PULL on the cable management system. Lift it up and outward to lock it in place to access the air filter.
- Loosen the captive screws on the corners of the air filter faceplate.
- Grasp the handles and pull the air filter straight out of the chassis.
- Remove the filter element from the air filter frame (see Figure 2).
Figure 1: Removing the Front Air Filter

Figure 2: Replacing the Front Filter Element

Installing a Front M320 Air Filter
To install the front air filter (see Figure 3):
- Attach an electrostatic discharge (ESD) grounding strap to your bare wrist, and connect the strap to one of the ESD points on the chassis.
- Insert the filter element into the air filter frame.
- Grasp the air filter by the handles on its faceplate, and slide it straight into the chassis.
- Tighten the captive screws on the corners of the faceplate.
- Unlock the cable management system, and lower it to the fully lowered position.
- Rearrange the PIC cables in the cable management system.
Figure 3: Installing the Front Air Filter

Removing a Rear M320 Air Filter
The rear air filter is located at the left rear edge of the chassis. The rear air filter weighs less than 1 lb (0.5 kg).
To remove the rear air filter:
- Attach an electrostatic discharge (ESD) grounding strap to your bare wrist, and connect the strap to one of the ESD points on the chassis.
- Loosen the captive screws at the top, center, and bottom of the air filter, using a Phillips (+) screwdriver, number 2.
- Grasp the air filter cover by the captive screws, and pull firmly to remove the cover and honeycomb assembly from the chassis (see Figure 4).
- Press the filter element inward until it clears the hooks at the top and bottom of the air filter slot, then push it to the left to unseat it.
- Move the tabs on the filter element to a horizontal position.
- Grasp the tabs on the filter element and carefully pull it straight out from the chassis (see Figure 5).
Figure 4: Removing the Rear Air Filter

Figure 5: Removing the Rear Air Filter Element

Installing a Rear M320 Air Filter
To install the rear air filter (see Figure 6):
- Attach an electrostatic discharge (ESD) grounding strap to your bare wrist, and connect the strap to one of the ESD points on the chassis. For more information about ESD, see Preventing Electrostatic Discharge Damage to an M Series, MX Series, or T Series Router.
- Align the filter with the right side of the air filter slot and carefully push the filter all the way into the slot. The top and bottom air filter guides direct the filter to the left as it is pushed into the slot.
- Holding the filter all the way in, push it to the right side of the slot until it is held in place behind the hooks.
- Place the right edge of the honeycomb against the flange of the air filter slot.
- Line up the holes at the top, center, and bottom of the honeycomb with the pins in the slot and press the honeycomb into place.
- Replace the air filter cover.
- Firmly tighten the captive screws at the top, center, and bottom of the filter cover to secure it to the chassis, using a Phillips (+) screwdriver, number 2.
Figure 6: Installing the Rear Air Filter

