INFO. ON SUPPLEMENTAL COOLANT ADDITIVE. Chevrolet Chevy MD FWD Control Chassis 1990

SUBJECT:INFORMATION ON SUPPLEMENTAL COOLANT ADDITIVE (NALCOOL 2000)

MODELS: 1990-94 CHEVROLET AND GMC TRUCK P6, B7 SCHOOL BUS 1990-94 TOPKICK/KODIAK

ALL MEDIUM DUTY TRUCKS BUILT IN JANESVILLE, STARTING WITH THE 1994 MODEL YEAR, HAVE THE NALCOOL 2000 BRAND ENGINE COOLANT ADDITIVE AS STANDARD. NALCOOL 2000* HAS BEEN STANDARD WITH THE CAT 3116 DIESEL ENGINES SINCE START OF 1993 PRODUCTION, AND OPTIONAL WITH GAS ENGINES BEFORE 1994. NALCOOL 2000 CONTAINS NITRITES WHICH INHIBIT CORROSION IN THE COOLING SYSTEM. CORRECT USE OF NALCOOL 2000 WILL REDUCE PITTING CORROSION OF ALUMINUM RADIATORS AND HEATER CORES. BECAUSE THE NITRITE INHIBITORS ARE DEPLETED OVER TIME, NALCOOL 2000 SHOULD BE ADDED TO THE TRUCK COOLING SYSTEMS ON AN ONGOING BASIS AS AN ECONOMICAL METHOD OF MAINTAINING PROPER INHIBITOR LEVELS. SPECIFICALLY, NALCOOL 2000 PERFORMS THE FOLLOWING FUNCTIONS:

- PROTECTS ALL SIX ENGINE METALS FROM CORROSION - MAINTAINS THE ALKALINITY (PH AND RA) OF THE COOLANT - REPLENISHES ANTIFOAM PROTECTION - CONTROLS SCALE FORMATION TO MAINTAIN COOLING EFFICIENCY

THERE ARE TWO WAYS TO MAINTAIN THE NALCOOL 2000 CONCENTRATION. ONE WAY IS TO ADD NALCOOL 2000 EVERY 6 MONTHS/6000 MILES, COINCIDING WITH OIL CHANGES. A SECOND, MORE PRECISE WAY IS TO OBTAIN A NITRITE TEST KIT AND ADD NALCOOL 2000 EXACTLY AS NEEDED BY THE TRUCK'S COOLING SYSTEM.

1. NITRITE TEST KIT METHOD OF MAINTAINING NALCOOL 2000

THE BEST INDICATORS OF PROPER CORROSION PROTECTION ARE THE CONCENTRATION LEVELS OF COOLANT AND NITRITE. THE NITRITE LEVELS OF NALCOOL 2000 ARE CONSTANTLY BEING DEPLETED AT A RATE THAT CANNOT BE PREDICTED. BY TESTING NITRITE LEVELS AT EACH OIL CHANGE, THE OPERATOR WILL KNOW WHEN TO ADD ADDITIONAL NALCOOL 2000. NALCOOL 2000 SHOULD BE MAINTAINED BETWEEN 3 PERCENT AND 6 PERCENT CONCENTRATION. MORE DETAIL INFORMATION IS AVAILABLE WITH THE TEST KITS. SUGGESTED SUPPLIERS FOR THE NITRITE TEST KIT ARE AUTHORIZED CATERPILLAR OR DETROIT DIESEL DISTRIBUTORS.

2. REGULAR MAINTENANCE METHOD OF MAINTAINING NALCOOL 2000

THE FOLLOWING CHART LISTS THE AMOUNT OF NALCOOL 2000 IN PINTS (LITERS) TO ADD TO THE COOLING SYSTEMS ON A REGULAR BASIS.

NALCOOL 2000 ADDITIVE TO TO ENGINE COOLING SYSTEM PINTS (LITERS)

ROUTINE MAINTENANCE COMPLETE FLUSH AND FILL OF THE COOLING SYSTSEM EVERY 6 MONTHS/6000 MILES EVERY 24 MONTHS/24,000 MILES ALL ENGINES GAS DIESEL TOPKICK AND KODIAK 1PT (.5L) 1.5PT (.72L) 2PT (1L)

B7 BLUE BIRD BUS W/30 FT. 2PT (1L) 3PT (1.5L) 4PT (2L) BODY (3 ADDITIONAL HEATERS PLUMBED FROM THE COOLING SYSTEM).

P6* 1PT (.5L) 1.5PT (.72L) 2PT (1L)

* IF THERE ARE ADDITIONAL INSIDE HEATERS PLUMBED TO THE INSIDE OF THE TRUCK THROUGH THE COOLING SYSTEM, CHECK WITH THE BODY BUILDER TO DETERMINE THE TOTAL CAPACITY OF THE COOLING SYSTEM. THEN FOLLOW NALCOOL 2000 INSTRUCTION FOR ADDITIVE BASED ON TOTAL SYSTEM CAPACITY.

THE MAINTENANCE MANUAL RECOMMENDS A COMPLETE FLUSH AND FILL OF THE COOLING SYSTEM EVERY 24 MONTHS/24,000 MILES. AT THAT TIME, NALCOOL 2000 SHOULD BE ADDED WITH A 50/50 MIXTURE OF CLEAN WATER (PREFERABLY DISTILLED) AND ANTIFREEZE THAT MEETS "GM SPECIFICATION 6038-M" WHICH WILL NOT DAMAGE ALUMINUM PARTS. YOU CAN ALSO USE A RECYCLED COOLANT CONFORMING TO "GM SPECIFICATION 6038-M."

SERVICE PARTS INFORMATION:

QTY P/N DESCRIPTION US/METRIC

1052103 GM ANTI-FREEZE OR ANTIFREEZE THAT MEETS 3-4 GAL/11-15L GM SPECIFICATION 6038-M 12346224 NALCOOL 2000 1 PT/.5L

PARTS ARE EXPECTED TO BE AVAILABLE FROM GMSPO ON 10/3/94.

WE BELIEVE THESE SOURCES AND THEIR EQUIPMENT TO BE RELIABLE. THERE MAY BE ADDITIONAL MANUFACTURERS OF SUCH EQUIPMENT. GENERAL MOTORS DOES NOT ENDORSE, INDICATE ANY PREFERENCE FOR OR ASSUME ANY RESPONSIBILITY FOR THE PRODUCTS OR EQUIPMENT FROM THESE FIRMS OR FOR ANY SUCH ITEMS WHICH MAY BE AVAILABLE FROM OTHER SOURCES.

FIGURES: 0

GENERAL MOTORS BULLETINS ARE INTENDED FOR USE BY PROFESSIONAL TECHNICIANS, NOT A "DO-IT-YOURSELFER". THEY ARE WRITTEN TO INFORM THOSE TECHNICIANS OF CONDITIONS THAT MAY OCCUR ON SOME VEHICLES, OR TO PROVIDE INFORMATION THAT COULD ASSIST IN THE PROPER SERVICE OF A VEHICLE. PROPERLY TRAINED TECHNICIANS HAVE THE EQUIPMENT, TOOLS, SAFETY INSTRUCTIONS AND KNOW-HOW TO DO A JOB PROPERLY AND SAFELY. IF A CONDITION IS DESCRIBED, DO NOT ASSUME THAT THE BULLETIN APPLIES TO YOUR VEHICLE, OR THAT YOUR VEHICLE WILL HAVE THAT CONDITION. SEE A GENERAL MOTORS DEALER SERVICING YOUR BRAND OF GENERAL MOTORS VEHICLE FOR INFORMATION ON WHETHER YOUR VEHICLE MAY BENEFIT FROM THE INFORMATION.