1993/04/12 Caterpillar

Adjustment Of 60670 Idle Air Lines Group (Idle Bleed Circuit){1266}

Usage:

I

G3516 (3RC, 4EK) Low Emissions Engines

SUPPLEMENT: June 14, 1993

Service Magazine; April 12, 1993; Page 8; "Adjustment Of 6I0670 Idle Air Lines Group (Idle Bleed Circuit)" for G3516 (3RC, 4EK) Low Emissions Engines

One of the measurements for adjusting the valve is NOT correct. The statement "* The exhaust temperature is at a maximum." should NOT be used as a condition to set the idle bleed circuit. The correct last sentence of the article follows:

Then slowly open the valve until one of the following conditions is met:

* The hertz meter reading on the switch gear reaches its most stable condition.

* The manifold vacuum reading is at a maximum.

--------------- END SUPPLEMENT ---------------

The idle bleed circuit is used to lean the fuel mixture of the low emissions engines at low idle speeds. See the illustration. Proper adjustment of the circuit creates the optimum conditions for low idle stability. The correct idle bleed circuit setting is determined by adjusting valve (1) while the engine is running at high idle conditions (rated rpm with no load). The valve should initially be closed. Then slowly open the valve until one of the following conditions is met:

* The exhaust temperature is at a maximum.

* The manifold vacuum reading is at a maximum.

* The hertz meter reading on the switch gear reaches its most stable condition.

Location of valve (1) in the idle bleed circuit.

Caterpillar Information System:

1993/04/12 New Seal Group Used In Water Pump Groups{1361}

1993/04/12 Fan Drive Pulley Group Components{1359}

1993/04/12 New Personality Modules Provide Improved Cruise Control{1902}

1993/04/12 Component Cross Reference Lists For Programed Electronic Engine Control (PEEC) And Electronic Systems{1900}

1993/04/12 7L4095 Exhaust Manifold Available For Parts Service{1059}

1993/04/12 Seal Kits Are Now Available For Balderson Hydraulic Hammers{6300,6333}

1993/04/05 Alternator Mounting Modifications{1405}

1993/04/05 New Alternator Support Bracket Used In Alternator Mounting Group{1405}

1993/04/05 Oversize Pistons Not Available{1214,1216}

1993/03/29 New Exhaust Manifold Group With Spring Energized Seals Between Cylinder Head And Manifold; New Exhaust Elbow And Seals In Air Lines Group{1059,1061,1052}

1993/03/29 Aftercooler Group Changed To Provide Stronger Housing{1063}

1993/03/29 Personality Modules Available For Bulk Hauler Applications{1902}

1993/04/12 New Expansion Tank Assembly Used In Expansion Tank Groups{1354}

1993/04/12 New Damper Guard Group Used{7150}

1993/04/12 New Bearing Assemblies Used On Main Shaft{3322}

1993/05/03 Governor Control Adjustment {1264}

1993/05/10 Service Tips For Effective Repair Of Failed Turbochargers{1052,1063,1059}

1993/05/10 0R3735 Remanufactured Camshaft Available{1210}

1993/05/10 New Low Crevice Volume (LCV) Piston Body Assembly Used{1214}

1993/05/17 Baffles Available To Help Reduce Turbocharger Noise {1052,1058}

1993/05/17 New Fuel Injection Lines, Clamps, And Brackets Used In Fuel Injection Lines Groups {1252}

1993/05/24 Summary Of Changes To Timing Advance Drive Groups{1272}

1993/05/31 New Fuel Injector Group Help Reduce Plunger And Barrel Seizures{1290}

1993/06/07 New Jacket Water Heater Mounting Groups Include Improved Hoses{1383}