SFN-20231006A_Replace the elbow that mounts the air switch

TICO Document #: SFN-20231006A (fromerly TES-191)

Issue: Air leaking at the 1/8” NPT 90° elbow fitting at the base of the air brake pressure switch

Description of Procedure: Replace the 1/8” NPT 90° elbow that mounts the air switch

Cause: Improper installation of the air switch results in air leaking from the fitting

Units Affected: 2017 Series Cab

Parts Required: 3/8” NPT STREET 90° ELBOW #40844 (QTY 1)

Instructions:

1. Park the vehicle on a flat surface, and apply the parking brake and chock wheels. If your company utilizes a “Lock Out, Tag Out” policy, you should employ it during this procedure.

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2. The locations of the switches are as follows:

• Two (2) switches are located behind the right-hand side front cab access panels (Detail 1)

• Another switch is located under the cab floor, on the brake valve (Detail 2).

3. Record the orientation of the switches and fittings for reassembly.

4. Remove damaged 1/8” NPT Elbow fitting. The elbow can be discarded.

5. If during the disassembly process, the existing switch should be installed into the bushing with sealant tape.

   CAUTION: Do not use a switch body to tighten. When using sealant tape on the switch threads, be sure that the tape does not plug the switch’s orifice. See detail 3.

6. Install the provided 3/8” NPT STREET 90° ELBOW (TICO part #40844).

7. Reinstall the fittings, per either detail below. Orientate the fittings as previously recorded. Cab interior switches use Detail 4. The switch under the cab floor on the brake valve uses Detail 5.

8. Remove “Lock Out, Tag Out” plaque.

9. Return vehicle to service.