1994/12/12 Caterpillar

New Exhaust Bypass Valve (Wastegate) Used In Exhaust Bypass Group{1057}

Usage:

793 (3SJ),
793B (1HL) Trucks

Reference: Service Magazine; September 26, 1994; Page 5; "Maintenance Guidelines For Exhaust Bypass Group". Service Magazine; October 17, 1994; Page 11; Supplements; "Maintenance Guidelines For Exhaust Bypass Group".

Description of Change: A new wastegate is used in the exhaust bypass group on the 3516 Machine Engines in these trucks. The new wastegate includes a new improved flex nomex diaphragm and a new valve stop to limit diaphragm travel. The limited travel will help prevent diaphragm tearing.

Illustration 1. Location of new 111-6118 Wastegate in the 4P-4862 Exhaust Bypass Group.

Adaptable To: The new 111-6118 Wastegate is a direct replacement for the former 107-8753 Wastegate in the 4P-4862 Exhaust Bypass Group on the 3516 Machine Engines in 793 and 793B Trucks. The new 111-6118 Wastegate is effective with 793B Truck 1HL159. The former wastegate is canceled.

Illustration 2 and the chart identify the new components that make the new 111-6118 Wastegate different from the former 107-8753 Wastegate.

Illustration 2. Identification of new components that make the new 111-6118 Wastegate different from the former 107-8753 Wastegate.

NOTE: 793 and 793B Trucks operating above 12,000 feet should have the wastegate group removed, or have the boost line to the wastegate disconnected and plugged.

Caterpillar Information System:

1994/12/12 Serviceable Parts For Custom Option Engine Prelube Group{1319}

1994/12/12 Injector Solenoids on Engines Equipped with EUI Are Not Polarity Sensitive{1259}

1994/12/12 Caterpillar Hose Press And Tool Usage{5057,0684}

1994/12/12 Procedure To Bleed And Charge The Rear Suspension{7213}

1994/12/12 Procedure For Measuring Oscillating Hitch Wear {7113,7114}

1994/12/05 Dry Start Priming Procedure for 3500 Machine Engines with Electronic Unit Injection (EUI){1250,1258}

1994/12/05 Flexible Hose Assembly Replaces Tube Assemblies In Turbocharger Water Lines Groups{1380}

1994/12/05 Hardened Spacers Used In Steer Pivot{4300,7051,7066}

1994/12/05 New Muffler Bracket Improves Muffler Support{1062}

1994/12/05 New Differential Group Housing Used In The Output Gear Group{3159}

1994/11/28 Be Sure Correct Piston Cooling Jets Are Installed{1331}

1994/11/28 Improved Spring Used In Belt Tightener Groups{1358}

1994/12/12 New Cylinder Blocks Made From Stronger Alloy{1201}

1994/12/19 New Roller Bearings Used In The 8E-9034 Transmission Planetary Group To Improve Service Life {3160}

1994/12/19 Small Cracks Around The Holes In The Front Wheels Can Be Repaired By Welding {4201}

1994/12/19 New Screen Assembly Prevents Large Debris From Transferring Into Differential Compartment {4051,3258}

1994/12/19 Primary Pressure For The Transmission Pressure Control Group Has Been Increased {0374,3150}

1994/12/19 New Filter Used For Screed Burner And Washdown Systems {1274,5642}

1994/12/19 Spacer Plate Is Available To Make Installation Of Permanent Hose Couplings Easier {0684,5057}

1994/12/19 Special Instruction SEHS9734-01 Is Available For Retrofitting R-12 Air Conditioning Systems To R-134a Refrigerant {7320,1809}

1994/12/19 New Connecting Rod Assembly Has Increased Fatigue Strength {1218}

1994/12/19 New Water And Oil Temperature Regulators Available {1330,1355}

1994/12/19 New Electronic Control Group (Throttle Position Sensor) Has Improved Contact Design {1913}

1994/12/26 New Engine Oil Pressure Gauge And Sender {7455}