SFN-20240116E Install new airline

TICO Document #: SFN-20240116E (formerly TES 142)

Description of Procedure: Air line for the air pressure gauge is plumbed into auxiliary circuit of air tank which is controlled via a pressure protection valve. A new air line routing is required to plumb the supply to the air pressure gauge into the delivery circuit of the air tank.

Units Affected: All units with trailer auxiliary brake feature and split brake air systems.

Parts Required: Fitting, Tee Branch, Brass, 3/8 NPT 40873 (QTY 1)

Tubing, Nylon Air-Brake, 3/8” Black 11004 (QTY 5)

Fitting, Plug, 3/8 NPT 40841 (QTY 1)

Planned Labor: 45 minutes

Instructions:

1. Park vehicle on flat surface, apply 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. Release/vent all air in the system. This can be done by manually releasing valves at the bottom of the air tank

3. In cab, remove six # 10 machine screws securing 5th wheel/shifter panel and lift up so that air brake lines on valves are visible. Retain machine screws.

   Note: 5th wheel/shifter panel is shown uninstalled for clarity.

4. Disconnect existing 3/8” black airline currently attached to primary supply port on MV3 valve. Route 3/8” black airline, 11004, from primary supply port down through column with other airlines.

5. Raise cab fully and engage cab latch. Ensure cab latch locks into position before performing any service.

6. Locate auxiliary air manifold on left-hand side of floor. Remove 40887 on upper right-hand side of manifold and retain. Route ¼” airline to treadle, brake, valve.

7. Secure plug 40841 into port in which 40887 fitting was removed.

8. Locate treadle, brake, valve on left-hand side of cab floor.

9. Remove 42174 from brake valve and replace with 40887 previously removed. Retain 42174. Remove and discard 3/8” airline, 11004, previously routed to 42174, and airline routed from treadle valve to MV3 valve in dash.

10. Route ¼” airline previously attached to manifold to newly installed 40887 on brake valve.

11. Identify the 40885. Double-check valve located at the forward most position on the inner member of the cab floor.

12. Remove 5/16 locknut and flat washer securing 40885 to inner member of floor. Remove airlines routed to double check valve and mark from which port each was removed. Retain hardware.

13. Remove 40823 from rear of 40885 and plumb in branch tee, 40873, as shown.

14. Plumb 40823, one removed from treadle valve and the other removed during previous step, into each side of 40873.

15. Connect airline running from MV3 primary supply port to 40823 located on the right-hand side of 40885, as shown, and trim excess airline if necessary.

16. Reinstall double check valve, 40885, onto stud and secure with 5/16 locknut and flat washer previously removed.

17. Reattach airlines previously removed back into original ports with the exception of the 3/8” black airline being routed to the 40823 fitting on the outermost side of 40885, as shown.

18. Install split convolute tubing onto any exposed airlines.

19. Secure airlines from chafing with tie straps, and ensure that no lines have been kinked.

20. Lower cab and start engine.

21. Allow air pressure to build to 80 PSI.

22. Stop engine and drain air tanks using pull cord attached to manual air drain.

23. If air pressure fails to build or if air pressure fails to fall to zero then troubleshoot airline routing for kinks or leaks and ensure all lines are routed correctly. Repeat previous steps to build air pressure and drain air system. Verify proper gauge function.

24. Secure 5th wheel/shifter panel using six #10 machine screws previously removed.

25. Remove “Lock Out, Tag Out” plaque.

26. Return vehicle to service.