1997/05/19 Caterpillar

Improved Components For Air Lines Groups{1058,1063}

Usage:

793B (1HL34-Up),
793C (4AR1-Up) Off-Highway Trucks

Description of Change: Improvements have been made to the air lines groups in the above machines powered by 3516/3516B Engines. The change consists of an improved gasket with a metal core and a graphite impregnated sheet bonded to each side. Longer spacers, longer mounting bolts and thicker washers are used as part of the improvement. A counterbore has been added to the aftercooler core assembly, providing more consistent bolt stretch and thread engagement.

The improved hardware, gasket and added counterbore helps prevent loosening during thermal expansion and contraction from the heat of the engine.

Illustration 1. 9Y-8914 Air Lines Group right side view.
(1) Improved 103-0873 Gasket. (2) Counterbore within the 4P-6544 Aftercooler Core Assembly. (3) Improved 5D-9547 Spacer. (4) 8M-3175 Hard Washer. (5) 3S-0127 Bolt.

Illustration 2. 9Y-8914 Air Lines Group right side view. (6) 1T-0765 Bolt. (7) 5M-2894 Hard Washer.

Four bolts and four washers have been added on each end of the aftercooler core assemblies. The 1T-0765 Bolts are longer, in order to go through the improved 103-0873 Gasket. Two 5M-2894 Hard Washers are also added. See Illustration 2.

Adaptable To: The improved 5D-9547 Spacer, 8M-3175 Hard Washer, 3S-0127 Bolt and 103-0873 Gasket are used in the 9Y-8914 Air Lines Group. See the above chart for components and component changes. The improvements are effective with the above machines and adaptable back to first production.

NOTE: The 4P-6544 Aftercooler Core Assembly did not change.

Caterpillar Information System:

1997/05/19 New Engine Software Available For 3412E Engines In 24H Motor Graders{1920}

1997/05/12 New Cylinder Groups Use Piston For Internal Stop {7562,5101,5102,5104}

1997/05/12 Structural Improvement To Piston Permits Removal Of Piston Coatings {1214}

1997/05/12 Correction To 50 Hour Machine Lubrication Schedule {7521,6437,6451,6452}

1997/05/12 Dimensions To Produce Drive Shaft Sleeve {3253,3267}

1997/05/12 New Turbocharger Guard Now Used {1073}

1997/05/12 New Center Arms, Steering Arms And Lock Plates Used In Steering Linkage Groups To Improve Linkage Quality {4305,4300}

1997/05/12 Fabricated Rear Cross Tube Replaced With Casting To Improve Service Life {3268}

1997/05/12 New Engine Wiring Harnesses Allow Easier Engine Removal And Installation {1408}

1997/05/12 Improved Lever Assembly Allows Greater Clearance {5112,7117}

1997/05/12 Engine Support Tooling Available {3030,0701,0720,1001}

1997/05/12 Procedure To Investigate Misfires On Engines Equipped With Electronic Unit Injectors (EUI) {1290}

1997/05/19 Improved Crankcase Breather Group Is Available{1317}

1997/05/19 Cylinder Rod For Suspension Cylinder Groups Has Larger Diameter Bolts For Piston Retention{7201}

1997/05/19 Improvements Made To Prevent Alternator Terminal Breakage{1405}

1997/05/19 Dimensions For Installing Attachment Tailgate Mounting Hardware On Articulated Truck Dump Bodies{7271,7258}

1997/05/19 Torques For Wheel Nuts And Bolts Are Incorrect In The Operation And Maintenance Manual{4201,4202}

1997/05/19 Installation Of Transmission Oil Distributor Sleeves{5208,3002,3159,3176}

1997/05/19 Improved Speed Sensor Group Used{1907}

1997/05/19 New Electronic Transmission Control Group Used{3032,3100}

1997/05/19 New Differential Pinion Bearing Setting Tool And Procedure Available{3258}

1997/05/19 Torque Specified For Piston Rod Nut In Steering Cylinder Group{4303}

1997/05/19 New Antirotation Bearing Pins And Bearing Lubrication Lines Used On Rear Suspension Cylinder Bearings To Increase Service Life{7218,7213,7201,7200}

1997/05/19 Backup Alarms Improved{7406}