Cisco ASR 9901 Hardware Installation Manual page 144

Removing and Replacing the Air Filter
Regularly check the air filter at least every three months. If used in a dusty environment, check the air filter
once a month. Replace it if it appears excessively dirty or damaged. Failure to replace a compromised air filter
can result in insufficient air circulation through the chassis.
Note To comply with Telecordia GR-63-Core standard air filter requirements for NEBS deployments, the air filter
must be replaced.
Note The air filter can be removed from the air plenum assembly without removing the cables or the fan tray.
To replace the air filter, follow these steps:
Procedure
Step 1 Loosen the two captive screws on the air filter cover and remove it from the chassis.
Step 2
Grasp the pull tab in the center of the air filter, and slide it out from the slot.
Figure 110: Replacing the Air Filter
1 Air filter cover
3 Air filter
Step 3 Install the replacement air filter.
Cisco ASR 9901, ASR 9001, and ASR 9001-S Routers Hardware Installation Guide
136
2 Two captive screws
Replacing Router Components