1990/10/01 Caterpillar

Correct Light Bulb Replacement For The 8T9290 Borescope; New Light Bulb Used {0777}

Usage:

Reference: Operating Manual, Form NEHS0504, "Using The Inspection Borescopes" for 1U5268 and 8T9290 Borescopes.

Description of Change: In March 1989, Caterpillar's supplier of the 8T9290 Borescope provided an improved version of the borescope. A new light bulb with an improved design is used. The new design provides greater protection to the light bulb, and produces a larger field of view. These changes will increase the service life of the light bulb. Since the physical mounting of the new light bulb is different, a new part number for the light bulb is required.

Adaptable To: The new 4C6493 Light Bulb (B) is used in the improved 8T9290 Borescope. The former 1U6862 Light Bulb (A) is used in the earlier version of the 8T9290 Borescope. If the light bulb can not be removed from the cap of the borescope, replace it with the former light bulb (A) instead of the new light bulb. Complete instructions for the correct operation and maintenance of the borescope are included with each unit. Additional copies of the Reference are available through normal literature ordering channels.

NOTE: The new light bulb will only work in the improved 8T9290 Borescope. The former light bulb (A) CAN NOT be removed from the end cap.

(A) Former 1U6862 Light Bulb. Notice that the light bulb is exposed and has a metal tab on the side. (B) New 4C6493 Light Bulb.

Caterpillar Information System:

1990/10/01 What's Your Answer? {0114,1400}

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1990/09/24 Standard Oval And High Temperature Oval Head Seals Available For Certain Hydraulic Cylinder Applications{7555,5102,5456}

1990/09/24 Sealing Threads On Switches And Sensors That Are Grounded Through The Case{1400,1900,3175,7422,7493}

1990/09/17 New 4P0329 Pleasure Craft Cruise Kit Available For 3208 Marine Engines {1000}

1990/09/17 Be Sure To Use Correct Piston Pin With New Pistons {1225,1214}

1990/09/17 New Cylinder Head Group Available For Landfill Applications {1100,1104,1105}

1990/09/17 Special Instruction SEHS9177, Has Adjustment Procedure For Door Latch Assemblies And Strikers {7308}

1990/09/10 Voltage Regulator Droop Connections Are Shown Incorrectly In Service Manuals{4475}

1990/09/10 New Timing Specifications{1552}

1990/09/10 New Remanufactured 0R6183 Control Group (Personality Module) Available{1902}

1990/10/01 New 4C6090 Multichannel Temperature Selector Available To Aid In Diagnosing Low Power Complaints {0781}

1990/10/01 Incorrect Installation Of Slow-Moving Vehicle Sign (Triangle) May Affect Cooling Performance {7405,1353,7557}

1990/10/01 Answers To Quiz In This Issue {0114,1400}

1990/10/08 Serviced Parts Available For 8C4773 Electric Starting Motor Group{1453}

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1990/10/08 New Exhaust Valves Are Used In Caterpillar Remanufactured Cylinder Heads{1105,1101}

1990/10/08 Price Adjustments On Service Program Modules{1902,0782}

1990/10/08 New Pump Group With Bolt Dampers Used In Oil Pump Group{1304}

1990/10/15 Be Sure To Use Only 5P3975 Rubber Lubricant On The Core Assembly End Seals In Folded Core Or Multiple Row Module Radiators{1353,1351}

1990/10/15 Additional Clip And Hardware Prevent Damage To Fuel Line Of 4W6887 Instrument Panel{1261}

1990/10/15 New Temperature Regulators; Regulator Service Hours Changed{1330,0770,1355,7527,7543}

1990/10/22 Improved 3T2357 Horn Switch, 3T3453 Starting Aid Switch, 3T3947 Start Switch, 3T8514 Test Switch Assemblies {1416,1456}