1978/11/06 Caterpillar

Improvement Made To Solenoid In Electric Shut-Off Group{1259}

Usage:

627B ( 37V, 38V ),
637D ( 20W, 21W, 22W, 23W ) Scrapers;
3304 Engines (2B, 4B, 5B),
3306 Engines ( 66D, 67D ) and D333C Engines ( 23C ) Equipped With Electric Shut-Off Groups

Description of Change: A change has been made to the electric shut-off group on the above models. A spring and washer have been added to the shut-off solenoid to give a more positive return of the plunger to the normal (running or fuel-on) position after the engine is stopped. Formerly, magnetic forces in some conditions held the plunger in the shut-off position. With the plunger in the shut-off position, the engine can not be started.

Installation of 7N9966 Spring and 5J9105 Washer.

Adaptable To: The spring and washer can be installed on all engines that are equipped with the earlier electric shut-off solenoid.

INSTALLATION:

... Remove the 9M1311 Nut and 6N591 Shaft from the solenoid. See the illustration.

... Install the 7N9966 Spring and the 5J9105 Washer as shown; then install the shaft and nut on the solenoid.

... Adjust the amount of travel of the shaft in the solenoid. See the Service Manual for the correct procedure and specifications.

... Install the solenoid and check it for correct operation.

Caterpillar Information System:

1978/10/30 6V92 Plug Socket Is Available For The Removal And Installation Of Lubricant Plugs{0612}

1978/10/30 New Fuel Injection Nozzles Are Used In 3208 Truck Engines When Equipped With EGR{1254}

1978/10/23 In The Future There Will Be A Common Warning System For All Caterpillar Machines{7450,7301,7400}

1978/10/23 5P8690 Fixture Group And 5P8691 Socket Are Available For Easier Reconditioning Of 5M4169 Cam Followers{0622}

1978/10/23 Conversion Of Testers In Earlier 1P3550 Wiring Harness Tester Groups To Use Later Test Harness Assemblies With Receptacle Connections{0650,0651,1408}

1978/10/16 Tips For Service Information Retrieval System (SIRS) Users{0374}

1978/10/16 New Transmission Mounting Group Has Improved Design For Longer Service Life{1150,3000}

1978/10/16 Modification To Rack Adjusting Tool Needed For Higher Rack Settings{0654,1257}

1978/10/16 Caterpillar Fuel Injection Test Bench Book{0374}

1978/10/16 New Switch Group Used In Several Applications{1416}

1978/10/09 5P9736 Bracket-Link Now Available For Parts Service{0644}

1978/10/09 A New 5P9698 Frequency Calibrator Is Available For The Calibration Of Caterpillar Diagnostic Tools{0651}

1978/11/06 New Control Cover Gives Better Control Of Exhaust Gas Recirculation System{1080,1250}

1978/11/13 6V106 Post, 6V107 Stop And 6V108 Cap Now Available For Parts Service Of The 7S1100 Hose Press Arrangement{0660}

1978/11/20 Single Coil Shut-Off Solenoid Used In Place Of Dual (Two) Coil Shut-Off Solenoid{1259}

1978/11/20 Sender Unit For Engine Oil Pressure Gauge Moved To New Location On Truck Cab{7455}

1978/11/20 A Washer With Closer Tolerances Is Now Used In The Governor And Fuel Pump Drive Group{1288,7462}

1978/11/27 New Hose Has More Resistance To Heat{1074}

1978/11/27 New Coolant Temperature Regulator Has Flat Washer-Type By-Pass Valve{1355}

1978/12/04 Stronger Fan Adjustment Bracket Used In Fan Drive Group{1358,1359}

1978/12/04 Some Force Is Needed To Turn The Drive Shaft In All Tyrone Gear-Type Pumps; New Torque Value For Body Bolts Of Tyrone Gear-Type Pumps{5073}

1978/12/04 New Design Brace Used In 4N2905 Air Cleaner Group{1051}

1978/12/04 New Exhaust Valve Has Improved Three-Piece Construction{1105}

1978/12/04 90° Elbow Added To Air Cleaner Group To Prevent Damage To The Air Filter Service Indicator{1051,7452}