Usage:
793 (3SJ),
793B (1HL),
793C (4AR) Off-Highway Trucks
- SUPPLEMENT: JANUARY 5, 1998
Service Magazine; September 29, 1997; Pages 8 and 10; "Improvement To Air Conditioning Lines Group In The 793C Off-Highway Trucks For Reduced Engine Removal And Installation Time".
Page 9, Chart "Parts Required For Retro-fit Of 138-8887 Air Conditioner Lines Group", Item 16. The correct part number for Item 16 is 137-8061 Hose Assembly.
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Description of Change: Retro-fit of air conditioner lines group for reduced disassembly and assembly time.
Adaptable To: The 138-8887 Air Conditioner Lines Group is effective with 793C (4AR77-Up) Off-Highway Trucks. The 138-8887 Air Conditioner Lines Group is adaptable to all 793 Off-Highway Trucks equipped with 2A-6543 Air Conditioner Lines Group. Refer to following retro-fit procedure for installation of 138-8887 Air Conditioner Lines Group.
Illustration 1. Side view of 138-8887 Air Conditioning Lines Group.
Illustration 2. Front view of 138-8887 Air Conditioning Lines Group.
Illustration 3. Cross sections A-A through D-D of 138-8887 Air Conditioning Lines Group.
Procedure to Retro-fit 138-8887 Air Conditioner Lines Group
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Always wear goggles when working on air conditioning systems. The system is under pressure at all times, engine running or not. Escaping refrigerant R-134a can cause freezing of human flesh. Do not smoke while working on air conditioning. Inhaling refrigerant R-134a through any smoking material, although not toxic or flammable, can generate lethal phosgene gas and cause violent illness or death. Also, heat must never be applied to a charged system. See Air Conditioning And Heating Service Manual, Form No. SENR5664-03 and NEDG5065, for more information on removal and installation of hose assemblies and refrigerant from the system.
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1. Before any service work (removal and installation of components) is performed on the air conditioning system, it is first necessary to recover the refrigerant. Please refer to SENR5664-03 and NEDG5065 for the proper recovery procedure.
2. Cap all hose openings as they are removed or inserted, so that dirt is not able to enter the system.
3. Remove 2A-6736 Hose Assembly and one 9X-7381 Seal from air conditioning condenser and replace with 137-8062 Hose Assembly (2). Attach hose assembly to air conditioning condenser using one new 9X-7381 Seal (3), lubricate with refrigerant oil prior to assembly. Use existing 8M-2773 Clip (1) to secure hose assembly.
4. Remove 2A-6737 Hose Assembly and two 9x-7380 Seals from air conditioning compressor and replace with 138-1184 Hose Assembly (6). Use one new 9X-7380 Seal (7), lubricate seal with refrigerant oil prior to assembly. Use one existing 4K-8864 Clip (5) to secure hose assembly.
5. Install one 7K-3176 Coupling (36) to opposite end of each hose assembly. Tighten to a torque of 48.75 ± 1.25 N·m (35.846 ± .919 lb ft). Lubricate two 9X-7383 Seals (35) with refrigerant oil prior to assembly to coupling.
6. Install 7K-3176 Couplings (36) to 138-4734 Plate (33). Install 138-4734 Plate to radiator using two 7E-7547 Spacers (30), two 8T-4172 Bolts (31), two 7K-3304 Jam Nuts (27) and two 7X-7729 Washers (22).
7. Install one 5P-3948 Coupling (34) to each 7K-3176 Coupling (36). Tighten to a torque of 48.75 ± 1.25 N·m (35.8456 ± .919 lb ft). Lubricate two 9X-7383 Seals (35) with refrigerant oil prior to assembly to coupling.
8. Install 138-1204 Hose Assembly (8) to 5P-3948 Coupling (34) attached to 138-1184 Hose Assembly (6), using one 9X-7380 Seal (7). Install 138-1179 Hose Assembly (4) to 5P-3948 Coupling (34) attached to 137-8062 Hose Assembly (2) using one 9X-7380 Seal (7). Lubricate seals with refrigerant oil prior to assembly.
9. Install the opposite end of 138-1204 Hose Assembly (8) to 3E-3535 Dryer. Use two existing 8M-2773 Clips to secure hose assembly.
10. Install the opposite end of 138-1179 Hose Assembly (4) to 7K-3176 Coupling (36). Tighten to a torque of 48.75 ± 1.25 N·m (35.846 ± .919 lb ft). Lubricate 9X-7383 Seal (35) with refrigerant oil prior to assembly.
11. Remove 2A-6735 Hose Assembly, one 9X-7382 Seal, one 9X-7383 Seal (35) and replace with 137-8060 Hose Assembly (18) with new 9X-7383 Seal (35) to existing 101-8789 Accumulator (36). Install the opposite end to 5P-3928 Coupling (36). Tighten to a torque of 62.6 ± 1.4 N·m (46.03 ± 1.03 lb ft). Lubricate 9X-7384 Seal (33) with refrigerant oil prior to assembly.
12. Install 7K-3176 Coupling (36) to existing 138-4553 Plate (22) using one 7K-3304 Jam Nut (27). Tighten to a torque of 48.75 ± 1.25 N·m (35.846 ± .9191 lb ft). Install 5P-3928 Coupling (36) to 138-4553 Plate (22) with 5P-4106 Nut (35). Tighten to a torque of 62.6 ± 1.4 N·m (46.03 ± 1.03 lb ft).
13. Install 138-4553 Plate (22) to frame using two 8T-4195 Bolts (30) and two 8T-4121 Washers (31).
14. Install 137-8063 Hose Assembly (15) to 5P-3948 Coupling (34) with 9X-7383 Seal (35). Lubricate seal with refrigerant oil prior to assembly.
15. Install 137-8061 Hose Assembly (16) to 5P-3929 Coupling (34) with 9X-7383 Seal (35). Lubricate seal with refrigerant oil prior to assembly.
16. Install 137-8063 Hose Assembly (15) to existing 3E-4061 Fitting Assembly (30) with 9X-7381 Seal (3). Lubricate seal with refrigerant oil prior to assembly.
17. Install 137-8061 Hose Assembly (16) to existing 3E-4074 Fitting Assembly (31) with 9X-7382 Seal (17). Lubricate seal with refrigerant oil prior to assembly.
18. Remove 114-5334 Switch Assembly and existing 9X-7385 Seal (12). Replace with 114-5333 Switch Assembly (10) and new 9X-7385 Seal (29).
19. All refrigerant must be recovered before the evacuating procedure is started. Never discharge refrigerant through the vacuum pump. Please refer to SENR5664-03 and NEDG5065 for proper evacuating procedure.
20. Follow instructions in Air Conditioning and Heating Systems Manual for proper procedure for recharging air conditioning lines group.