2000-OSM, F1
8-73
2. Turn off oven air to the isothermal oven and allow all temperature zones to cool.
3. Turn off air supply to air cleanup unit.
4. Open the isothermal oven door.
5. Label the tubing on both sides of the associated unions with temporary numbered tape labels.
The labels are later used to ensure correct tubing connections when the air cleanup is reinstalled.
6. Using 7/16-inch and 5/16-inch open-end wrenches, disconnect the tubing connections from the
reducing unions.
7. Disconnect any retaining clamps that are securing the harness.
8. Remove the four Phillips head screws attaching the support brackets to the isothermal oven wall.
Secure the unit with your hand while removing the final top screws.
9. Lay the air cleanup assembly on a suitable work surface within the constrained length of the
heater harness. If only the air cleanup tubes are to be replaced, the harness will not require
further disconnection.
CAUTION
Wait 30 minutes before proceeding to open the Dual Air Cleanup Assembly.
10. Mark the top and bottom caps and housing with a grease pencil or permanent marker. When the
caps are replaced with the marks aligned, the support bracket holes will be correctly aligned.
11. Using a 9/64-inch Allen wrench, remove the four Allen head screws attaching the air cleanup top
cap to the outer housing.
12. Grasp the housing and top cap. Withdraw the internal body assembly from the housing.
13. Using tweezers or a small screw driver, remove the insulation from around the body assembly.
Retain it for later use.
Removing the Air Cleanup Tubes
1. Using a 1/4-inch open-end wrench, disconnect the air cleanup tube connections from the bottom
side of the cap.
2. To remove an air cleanup tube, remove the Phillips head screw and flat washer located in the
center of the body at the opposite end from the harness.
3. Grasp the long coiled or “pig tail” end of the tubing and pull the short nutted end through the body
assembly.
4. Repeat steps 2 and 3 for the second air cleanup tube, if applicable.
5. Carefully rotate the body assembly and remove the Phillips head retaining screw and flat washer.
6. Note the location of the cartridge heater, temperature probes and thermocouple. Carefully extract
the cartridge heater, probes and thermocouple from the air cleanup body.
7. Inspect the probe end of the wiring harness for damage. If any harness wiring or devices are
damaged, replace the harness as described in "Packing the Housing" and "Installing the Dual Air
Cleanup Assembly."