Replacing the M40e Rear Upper Impeller Assembly
The rear upper impeller assembly is located at the upper left of the rear of the chassis, as shown in M40e Chassis Description. It weighs about 4 lb (1.8 kg).
The assembly is hot-removable and hot-insertable, as described in M40e Field-Replaceable Units (FRUs).
Removing the M40e Rear Upper Impeller Assembly
To remove the rear upper impeller assembly (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. For more information about ESD, see Preventing Electrostatic Discharge Damage to an M Series, MX Series, or T Series Router.
- Loosen the thumbscrew at each corner of the impeller cover, using a Phillips screwdriver if necessary.
- Grasp the thumbscrews at opposite corners of the
impeller cover and slide the assembly halfway out of the chassis.

Caution: To avoid injury, as you slide the assembly out of the chassis do not touch any part of the impeller behind the front panel—the impeller might still be spinning.
- When the impeller is no longer spinning, slide the assembly completely out of the chassis.
Figure 1: Removing the Rear Upper Impeller Assembly

Installing the M40e Rear Upper Impeller Assembly
To install the rear upper impeller assembly (see Figure 2):
- 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.
- Slide the assembly all the way into the chassis.
- Tighten the thumbscrew at each corner of the impeller cover.
Figure 2: Installing the Rear Upper Impeller Assembly

