1998/06/01 Caterpillar

New Water Pump Used{1350,1361}

Usage:

C-10 (8YS) C-12 (9NS) Truck Engines

Description of Change:

A new water pump is now used for the above engines. The new water pump includes the following features that improve the reliability of the pump:

* Enlarged weep hole

* Improved bellows material

* Porous silicon carbide faces on the coolant seal

Adaptable To:

The new 153-8053 Water Pump Group is a direct replacement for the former 100-6944 Water Pump Group. The 100-6944 Water Pump Group has been cancelled. The new 153-8053 Water Pump Group is adaptable to the above engines back to first production. The new 153-8053 Water Pump Group was effective in production for these serial numbers:

* C-10 (8YS02560-UP)

* C-12 (9NS06590-UP)

Caterpillar Information System:

1998/06/01 Be Sure To Use The Correct Spacer With The New 152-3001 Injector Hold Down Bolt In Fuel Injection Pump Group{1290}

1998/06/01 Be Sure To Heat The Gear To The Correct Temperature When Installing The Crankshaft Gear{1204}

1998/06/01 New Camshaft Gasket Available{1150,1151,1162,1166}

1998/06/01 Timing Hole In Wrong Location In Allison Flexplates{1003}

1998/06/01 New Basic Water Pumps Groups Used In Engine Water Pump Groups{1361}

1998/06/01 New Fuel Injection Nozzle With Higher Valve Opening Pressure (VOP) Used{1254}

1998/06/01 New Guideline For Product Information, SEBF8340, " Fuel Systems Troubleshooting Guide For 3204, 3300, And 3400 Engines With New Scroll Fuel Systems (NSFS)" Available{0374,1250}

1998/06/01 New Longer V-Belt Used For 3126 Truck Engines{1357}

1998/06/01 Cooling System Improved{1350}

1998/06/01 Correct Location For Pressure Tap To Measure Exhaust Backpressure{1061}

1998/05/01 Proper Welding Procedure On Truck Engines With Electronic Controls{1400}

1998/05/01 New Software Released{1920}

1998/06/01 "Horton 3-Speed Fan" Feature In Heavy Duty Truck Engine Software (FEB98 Or Later){1356,1920}

1998/06/01 Individual Parts For The Exhaust Joint Are Now Available{1059}

1998/06/01 Be Sure To Order The Correct Remanufactured Cylinder Head For 3406E (5EK, 6TS) Truck Engines{1100}

1998/06/01 New Flywheel Housing Gasket Used{1157}

1998/08/01 Prevention Of Air Cleaner Contamination On 1997 And 1998 GMC T-Series Tilt Cab Trucks Powered By 3116 (8WL, 2CW) And 3126B (7AS) Truck Engines{1051}

1998/08/01 Lower O-Ring Seal Removed From Hydraulically Actuated Electronically Controlled Unit Injector (HEUI) Groups{1290}

1998/09/01 Troubleshooting Reminder For Low Power Or Intermittent Low Power Symptoms {1250,1252,1256,1260,1261,1273}

1998/09/01 Flash File Bulletin Board System To Be Discontinued {1920}

1998/09/01 "Programming Cat Electronic Truck Engines" Update {1920}

1998/09/01 New Basic Water Pumps Groups Used In Engine Water Pump Groups {1361}

1998/09/01 Troubleshooting The 5 Volt Sensors {1900,1906,1917,1921,1922,1923,1924,1928}

1998/09/01 Be Sure To Heat The Gear To The Correct Temperature When Installing The Crankshaft Gear {1204}