SERVICE BULLETIN (Not applicable to Mack Trucks Australia) NUMBER: SB-261-009 DATE: 7/1/03 MODEL: CX, CV, CH, CL MERITOR WABCO 636 AIR COMPRESSOR RETROFIT KIT FOR CX, CV, CH AND CL MODELS WITH E-TECH ENGINES The Meritor WABCO 636 Twin Cylinder air compressor is a 28 cfm compressor designed for greater durability, higher efficiency and greater air output. These compressors feature many design improvements that offer a significant reduction in oil passing to minimize air dryer and air system contamination. A retrofit kit (part No. 146SB1) is available through the MACK Parts System if it is desired to replace any existing air compressor with a Meritor WABCO 636 compressor on a CX, CV, CH or CL model chassis equipped with an E-Tech engine. Parts included in the retrofit kit are as follows: This retrofit kit cannot be used on any chassis having a compressor-mounted power steering pump. Meritor WABCO 636 Compressor Retrofit Kit Qty. Part No. Description 1 8235-9115150050K Air compressor, WABCO 636 1 253GC3191 Bracket, mounting 4 26AM12 Flanged hex head capscrew, M8 x 1.25 x 20 mm 2 66AM4 Flanged hex head capscrews with patch-lock, M10 x 1.5 x 25 mm 1 590GB2159 Gasket, mounting 4 83AX838 Clamp, hose, Type-F extended band, No. 16, diameter, 1.50 max. 0.81 min. 1 83AX823 Clamp, loop, rubber cushion 1-ft 160AX526F Hose, 3/4, 1 foot length 1 42QE2307P2 Hose 1 40QE2143M Fitting, intake 1 63AX3710 Fitting, discharge air 2 63AX3673 Fitting 3 27AM16 Flanged hex head capscrew, M12 x 1.75 x 40 mm, compressor mounting 3 37AX83 Flat washer, 7/8, compressor mounting 8-ft 973AX420RF Hose, No. 6, 8 foot length 4 63AX1719R Hose end, No. 6 1 63AX3672 Fitting 6-ft 973AX100RF Hose, No. 4, 6 foot length 2 63AX1717R Hose end, No. 4 1 63AX212 Plug, 3/8-NPT SB-261-009 Page 1 of 14 SERVICE PUBLICATIONS, ALLENTOWN, PA 18105 MACK TRUCKS, INC. 2003
Meritor WABCO 636 Compressor Retrofit Kit Qty. Part No. Description 1 63AX83 Plug, 1/2-NPT 1 5166-59214 Pipe thread sealant 1 83AX884 Clamp In addition to the components included in the 146SB1 retrofit kit, the following additional parts will be required depending upon chassis model and the existing air compressor. These parts must be ordered separately. For CH or CX model chassis originally equipped with a Bendix Tu-Flo 550, Tu-Flo 750 or WABCO 318 compressor, the following additional parts will be required: Qty. Part No. Description 1 17QE520M Tube, intake 1 45MD419M2 Elbow, intake For CH or CX model chassis originally equipped with a Bendix Tu-Flo 1400 compressor, the following additional parts will be required: Qty. Part No. Description 1 17QE520M Tube, intake 1 45MD419M2 Elbow, intake 1 45MD422M Elbow, intake For CL model chassis originally equipped with a Bendix Tu-Flo 550, Tu-Flo 750 or WABCO 318 compressor, the following additional parts will be required: Qty. Part No. Description 1 17QE524M Tube, intake 1 45MD432M2 Elbow, intake For CL model chassis originally equipped with a Bendix Tu-Flo 1400 compressor, the following additional parts will be required: Qty. Part No. Description 1 17QE524M Tube, intake 1 45MD432M2 Elbow, intake 1 45MD422M Elbow, intake For CV model chassis originally equipped with a Bendix Tu-Flo 550, Tu-Flo 750 or WABCO 318 compressor, the following additional parts will be required: Qty. Part No. Description 1 17QE521M Tube, intake 1 45MD320M7 Elbow, intake SB-261-009 Page 2 of 14
The Meritor WABCO 636 air compressor retrofit kit (part No. 146SB1) is not to be used as the warranty replacement of an existing air compressor. Procedures for installing the Meritor WABCO 636 compressor are as follows: 1. Secure the chassis for service, block the wheels and apply the parking brakes to prevent the vehicle from moving. 2. Drain the coolant from the cooling system into a clean container so that the same coolant can be used to refill the system. 3. Remove the cab floor board. 4. Remove the right-side inner fender. 1 Figure 1 Remove Right-Side Inner Fender 5. Remove the exhaust pipe from the turbocharger outlet connection, and disconnect the flex pipe from the exhaust pipe under the cab. 2 Figure 2 Remove Exhaust Pipes SB-261-009 Page 3 of 14
6. Remove the air inlet ducts and elbows from the air cleaner to the turbocharger, then remove the air cleaner assembly. 3 Figure 3 Remove Inlet Air Elbows, Ducts and Air Cleaner Assembly 7. Remove the existing air compressor, coolant hoses, oil return line and brackets. SB-261-009 Page 4 of 14
8. If the existing compressor being replaced is a Bendix Tu-Flo 1400, remove the oil return fitting from the oil pan, then install a 1/2 NPT pipe plug (part No. 63AX83) in the oil return port in the oil pan. 9. Install a 3/8 NPT pipe plug (part No. 63AX212) in the coolant supply port in the cylinder block. Pipe sealant (MACK part No. 5166-59214) should be applied to the threads of all pipe plugs and fittings. 4 Figure 4 Install Pipe Plugs in Oil Return and Coolant Supply Ports Key Qty. Part No. Description 1 1 63AX83 Plug, 1/2 NPT (when replacing Bendix Tu-Flo 1400 compressor) 2 1 63AX212 Plug, 3/8 NPT SB-261-009 Page 5 of 14
10. Remove the 1/8 -to-no. 4 T-fitting from the existing air compressor, and install into the governor port of the new compressor. Also install fitting (part No. 63AX3710) into the discharge port of the new compressor. 5 Figure 5 Install Fittings into Governor and Discharge Ports of New Air Compressor Key Qty. Part No. Description 1 1 63AX3710 Fitting, compressor discharge port 2 1 existing T-fitting, 1/8 -to-no. 4, compressor governor port 11. Thoroughly clean the air compressor mounting surface on the engine block. 12. Remove the oil feed tube from the air compressor drive coupling and install into the auxiliary shaft. If the tube is missing or damaged, use a new tube (part No. 670GC276). 6 Figure 6 Install Oil Feed Tube into Auxiliary Shaft SB-261-009 Page 6 of 14
13. Position a new gasket (part No. 590GB2159) onto the air compressor mounting flange, then install the compressor to the engine. Use three bolts (part No. 27AM16) and three washers (part No. 37AX83). Tighten the mounting bolts to 70 lb-ft (95 N m). 14. Install the air compressor rear support bracket (part No. 253GC3191) using mounting bracket-to-compressor capscrews (part No. 26AM12) and mounting bracket-to-cylinder block capscrews (part No. 66AM4). Tighten the capscrews to the following specifications: Mounting Bracket-to-cylinder block (66AM4) 50 lb-ft (67.8 N m) Mounting Bracket-to-compressor (26AM12) 20 lb-ft (27 N m) 7 Figure 7 Air Compressor Installation Key Qty. Part No. Description 1 1 8235-9115150050K Air compressor, WABCO System Saver 636 2 1 590GB2159 Gasket, compressor mounting 3 3 27AM16 Flanged hex head capscrews, M12 x 1.75 x 40 mm, compressor mounting 4 3 37AX83 Flat washers, 7/8, compressor mounting 5 1 253GC3191 Bracket, compressor rear mounting 6 2 26AM12 Flanged hex head capscrews, M8 x 1.25 x 20 mm, mounting bracket-to-compressor 7 2 66AM4 Flanged hex head capscews, M10 x 1.5 x 25 mm, mounting bracketto-cylinder block SB-261-009 Page 7 of 14
15. Install the 90-degree fittings (part No. 63AX3673) into the coolant inlet and outlet ports located in the top of the air compressor. Optimum routing for the air compressor coolant lines is to have the coolant supply line routed to the forward port in the compressor, and the coolant return line routed to the rearward port in the compressor. Orient the fittings as shown in the following illustration. 8 Figure 8 Coolant Inlet and Outlet Fittings and Line Routing More efficient coolant flow to the air compressor can be obtained by supplying coolant to the compressor from the water manifold rather than from the coolant inlet port located at the right rear corner of the cylinder port. SB-261-009 Page 8 of 14
16. Remove the 1/2 pipe plug from the top rear section of the water manifold. 9 Figure 9 Remove Pipe Plug from Water Manifold 17. Install a 1/2 NPT 90-degree elbow fitting (part No. 63AX3672) into the port in the water manifold from where the pipe plug was removed. Orient the fitting so that it faces directly toward the rear of the engine. 10 Figure 10 Fitting Installed in Water Manifold 18. Fabricate a coolant line using approximately 41 (1041.4 mm) of No. 6 hose (part 973AX420RF) and two hose end fittings (part No. 63AX1719R). SB-261-009 Page 9 of 14
Line length will vary depending upon chassis model and special equipment. Always measure the amount of hose needed and fabricate the line accordingly. 19. Install one end of the hose to the elbow fitting installed in the water manifold, then route the hose around the back of the cylinder block and down to the compressor. Connect the hose to the elbow fitting installed in the forward port on the air compressor cylinder head. 20. Using an M12 x 1.75 x 20 mm bolt (part No. 27AM61, not included in kit) and clamp (part No. 83AX884), clamp the coolant line to the back of the cylinder block. Secure the clamp to the bolt hole located on the left-hand side of the cylinder block. 11 Figure 11 Bolt Hole Location in Cylinder Block 21. Fabricate a coolant line using approximately 46 (1168.4 mm) of No. 6 hose (part No. 973AX420RF) and two hose end fittings (part No. 63AX1719R). Line length will vary depending upon chassis model and special equipment. Always measure the amount of hose needed and fabricate the line accordingly. SB-261-009 Page 10 of 14
22. Install the coolant line between the water pump fitting and the elbow fitting located in the rear port on the air compressor cylinder head. Use the existing clamps to secure the hose. 23. Using approximately 71 (1803.4 mm) of No. 4 air line (part No. 973AX100RF), connect one end of the line to the air governor signal port. Connect the lines from the air governor and air dryer to the air compressor port. Line length will vary depending upon chassis model and special equipment. Always measure the amount of hose needed and fabricate the line accordingly. SB-261-009 Page 11 of 14
24. Install the steel air intake tube to the air compressor air inlet fitting, and secure to the back of the engine block. Intake tube part numbers vary by chassis model. Refer to the following table for a list of part numbers. 12 Figure 12 Air Compressor Intake Tube Installation Key Qty. Part No. Description 1 1 17QE520M Steel intake tube between compressor and air cleaner, CX and CH models 1 17QE524M Steel intake tube between compressor and air cleaner, CL models 1 17QE521M Steel intake tube between compressor and air cleaner, CV models 2 1 ft. 160AX526F Coupling hose, intake tube to inlet air duct 3 4 83AX838 Clamp, hose 4 1 42QE2307P2 Coupling hose, intake tube to air compressor fitting 5 1 83AX823 Clamp 6 1 26AM12 Bolt 25. Connect the main discharge line to the fitting installed in the air compressor discharge port. SB-261-009 Page 12 of 14
26. A new inlet air elbow at the air cleaner must be used to provide a connection point for the air compressor inlet tube. Part numbers for the inlet air elbow vary by chassis model. Refer the following table for a listing of the inlet air elbow part numbers. 13 Figure 13 Inlet Air Elbow Air Cleaner End Key Qty. Part No. Description 1 1 45MD419M2 Inlet air elbow, CX and CH models 1 45MD320M7 Inlet air elbow, CV models 1 45MD432M2 Inlet air elbow, CL models 2 1 40QE2143M Bulkhead fitting Install the bulkhead fitting (part No. 40QE2143M) into the hole provided in the new inlet air elbow. On CH, CX and CL model chassis originally equipped with a Bendix Tu-Flo 1400 air compressor, inlet air to the air compressor was provided through a fitting located in the inlet air elbow at the turbocharger. On these chassis, it will be necessary to replace the existing inlet air elbow at the turbocharger with elbow part No. 45MD422M. 27. Install the air cleaner assembly, inlet air elbows and ducts. Tighten all inlet air elbow and duct clamps to 75 lb-in (8.5 N m) on CX and CH models, and 50 lb-in (5.6 N m) on all other models. 28. Connect the air compressor intake tube coupling hose to the bulkhead fitting in the inlet air elbow at the air cleaner. 29. Reinstall the exhaust pipe, cab floor panel and inner fender. SB-261-009 Page 13 of 14
30. Refill the cooling system with the proper coolant, and check the level of anti-freeze protection. 31. Start the engine and check for coolant leaks, and for air leaks at all the compressor connections. 32. Check the governor for correct setting. Governor cut-in and cut-out should be as follows: Cut-in 100 105 psi (689.5 724 kpa) Cut-out 130 135 psi (896.4 930.8 kpa) SB-261-009 Page 14 of 14