Inspection of the Air Cleaner

122SD mm 09.00.01

Restriction of air flow through the air cleaner element is measured at the tap in the air cleaner outlet. Check the restriction indicator at the air cleaner or in the cab if the vehicle is equipped with a dash-mounted restriction gauge.

Vehicles may be equipped with either a manual-reset restriction indicator with graduations, as shown in Fig., or a go/no-go restriction indicator without graduations, as shown in Fig..

Fig. 1, Manual-Reset Air Restriction Indicator, Graduated

Fig. 2, Manual-Reset Air Restriction Indicator, Go/No-Go

  1. Inspect the air restriction indicator to see if air restriction equals or exceeds the maximum allowable restriction. For instructions, see Group 09 of the 122SD and Coronado Workshop Manual.
  2. Inspect the air cleaner housing for cracks, leaks, or any other damage. If the air cleaner housing or element is damaged, replace it.
  3. Check the inserts at all four assembly fastener locations (see Fig.). Each insert should protrude from the housing as shown in Fig..

    1. Air Cleaner Element Housing

    2. Air Cleaner Element

    3. Housing Cover

    4. Screws

    5. Inserts

    Fig. 3, Air Cleaner Assembly

    Note: Each insert should protrude from the housing as shown in item A.

    • Proper Fastener Installation

    • Damaged Insert, Flush

    • Damaged Insert, Countersunk

    1. Insert

    2. Screw

    Fig. 4, Air Cleaner-Housing Fasteners

    4. Notice: Do not use aftermarket air cleaner elements. Aftermarket air cleaner elements may not seal the housing correctly, which can lead to engine damage and potentially the loss of warranty. When replacing an air cleaner element, use only the part listed in PartsPro for the serial number of the vehicle.

  4. If necessary, replace the air cleaner element. For air cleaner element replacement instructions, see Group 09 of the 122SD and Coronado Workshop Manual.
  5. Inspect the forward and rear mounting isolators for damage. See Fig.. Ensure the bonds between the rubber and the steel plates are completely intact. See Fig.. If a mounting isolator is damaged, replace it. For isolator replacement instructions, see Group 09 of the 122SD and Coronado Workshop Manual.

    1. Air Cleaner Housing and Cover

    2. Front Isolator Top Nuts (2)

    3. Air Restriction Indicator

    4. Air Cleaner-to-Air Intake Duct Hose Clamp

    5. Air Intake Duct

    6. Front Isolators (2)

    7. Rear Mounting Bracket

    8. Rear Mounting Bracket Capscrews (2)

    9. Rear Isolator

    10. Rear Isolator Mounting Capscrews (2)

    11. Rear Isolator Nut

    Fig. 5, Air Cleaner Assembly

    1. Steel Plate

    2. Rubber

    Fig. 6, Mounting Isolator

  6. Remove the pre-cleaners (if so equipped) from the hood plenum, then clean them with compressed air.
  7. Reset the air restriction indicator.
  8. Each time the air cleaner housing is replaced, perform the procedures in MOP 13–01.
Note:
Parent topic: Air Intake
Document Number: 0000125446
Manual Publication Date: 2025-02-11
Topic Publication Date: 2024-06-21