Service Procedure A & B
Service Procedure AFor Service Procedure A, the cleaner should be left in the system for three hours (after normal operating temperature of the cooling system has been achieved). Normal operating temperature is when the coolant temperature stabilizes around 98°C (200°F). The best results are obtained when the coolant temperature is between 98°C (200°F) and 110°C (230°F). DO NOT EXCEED 113°C (235°F). Use the Scan Tool to determine when this point has been reached. When this temperature has been reached, start the clock. Periodically (every twenty minutes or so), monitor the coolant temperature and engine during the three hour run time. A half hour has been built into the actual labor time to cover for the time spent monitoring the engine, etc.
In order to achieve a constant temperature of 98°C (200°F) to 110°C (230°F) during this procedure, maintain the idle speed, turn on the A/C or partially close the hood.
Service Procedure B
For Service Procedure B, the cleaner should be left in the system for two and a half hours (after normal operating temperature of the cooling system has been achieved). Normal operating temperature is when the coolant temperature stabilizes around 98°C (200°F). The best results are obtained when the coolant temperature is between 98°C (200°F) and 110°C (230°F). DO NOT EXCEED 113°C (235°F). Use the Scan Tool to determine when this point has been reached. When this temperature has been reached, start the clock. Periodically (every twenty minutes or so), monitor the coolant temperature and engine during the two and a half hour run time. A half hour has been built into the actual labor time to cover for the time spent monitoring the engine, etc.
In order to achieve a constant temperature of 98°C (200°F) to 110°C (230°F) during this procedure, maintain the idle speed, turn on the A/C or partially close the hood.
Important:
The vehicle should not be left idling outdoors when the ambient temperature is below 10°C (50°F). The flushing procedure relies on heat as a catalyst in order to be effective. Ambient temperatures below 10°C (50°F) do not allow sufficient cycling of the thermostat to effectively clean the cooling system.
23. Turn off the engine.
24. Remove the dime from the closed throttle stop screw. Do NOT remove the radiator cap. Following the procedure listed below will assist you in draining the cooling system thoroughly.
^ Place a drain pan under the radiator drain hose.
Caution:
The cooling system and coolant are hot and under pressure. Loosen only the radiator drain until the pressure has been released from the cooling system and follow the procedures exactly in this bulletin, using normal safety precautions to avoid being injured by the hot coolant mixture.
Loosen the radiator drain. Drain approximately 1 L (1 qt) of liquid from the system.
^ After the pressure has been released from the cooling system, slowly loosen the radiator cap to the safety stop. Do not remove the cap (This releases the spring pressure on the secondary seal while retaining the primary seal to the top of the filler neck and will allow the coolant reservoir to be evacuated).
^ When the coolant reservoir is empty, re-tighten the radiator cap fully.
^ Remove the cap from the flush and fill "T". This will allow the coolant to be siphoned from the heater core and the engine block.
^ When the water has stopped coming out of the radiator drain hose, close the radiator drain. Do not place the cap on the "T".
25. Using Prestone(R) Heavy Duty Cooling System Cleaner, GM P/N 12346500, mix the neutralizer (from the bottom of the can) with approximately 3 L (3 qt) of warm (shower temperature) water.
Notice:
Do not put cold water into a hot engine as engine damage may occur.
Under no circumstances should the neutralizer be left in the cooling system for any longer than ten minutes once the vehicle has reached operating temperature (thermostat open). The neutralizer is corrosive to aluminum and will damage system components if it is left in the cooling system for longer than ten minutes.
Pour the mixture from the step above into the radiator.
26. Completely refill the cooling system with warm to hot water through the "T". When the radiator is full, install the radiator cap to the safety catch. Continue to fill until the overflow reservoir is filled to the hot line on the reservoir.
27. Remove the fill hose and install the cap on the "T" and the radiator fully.
Important:
It is imperative that all air pockets have been removed in order for the procedure to be effective.
28. Start the engine. After engine speed stabilizes, reinstall the dime between the closed throttle stop and the screw. With the A/C on, bring the cooling system back to normal operating temperature and follow the directions on the can.
29. Turn off the engine.
30. Remove the dime from the closed throttle stop and the screw.
Caution:
As long as there is pressure in the cooling system, the temperature can be considerably higher than the boiling temperature of the solution in the radiator without causing the solution to boil. Removal of the radiator cap while the engine is hot and pressure is high will cause the solution to boil instantaneously - possibly with explosive force - spewing the solution over the engine, fenders and the person removing the cap.
31. Drain the cooling system, following the procedure listed in Step 24.
32. Do not close the radiator drain. Leave it open.
33. Disconnect the upper radiator hose from the radiator. Properly position the hose, so the accessory drive belt or any pulley/belt cannot touch the hose.
34. Attach a garden hose to the "T" of the flush and fill kit. Turn on the water and back flush the cooling system for at least two minutes after the water runs clear.
35. Start the engine and continue back flushing the cooling system for five additional minutes.
36. Turn the engine "OFF".
37. Turn the water "OFF".
38. Close the radiator drain.
Important:
If the repair is a Procedure A, go to Step 40. If the repair is a Procedure B, remove the radiator and have it recorded and steam clean the end tanks. After reinstalling the radiator, continue to Step 40.
39. Remove the air cleaner housing and tube assembly from the throttle body.
40. Remove the two nuts holding the throttle cable bracket to the throttle body and position the bracket and the cables out of the way.
41. Remove the thermostat.
42. Remove the previously installed flush kit "T" and hose. Save for future use on other vehicles.
43. Install the heater inlet hose to the intake manifold and secure with the original spring clamp.
44. Inspect the thermostat opening and cover for foreign material. Clean if necessary.
45. Remove the left lower water pump crossover bolt to drain the left side of the block and the left cylinder head.
46. Install sealant to the bolt threads, using GM P/N 12346004 (Canada GM P/N 10953480), or equivalent and reinstall the water pump crossover bolt.
Tighten
Tighten the bolt to 41 N.m (30 lb ft).
47. If available, use coolant exchanger Pro-Fill, Power Flush, or equivalent to fill the system with 50/50 DEX-COOL(R) coolant. If a coolant exchanger is not available, proceed to the next step now. Follow the manufacturer's instructions for system fill/coolant exchange. If you are using coolant exchange equipment, you will need to install a new thermostat, GM P/N 12563335 and top off the system with clean drinkable water prior to exchanging. After exchanging, install the upper radiator hose and clean out the coolant recovery bottle. Proceed to Step 56.
48. Pour 5.6784 L (6 qts) of 100% (not pre-mixed) DEX-COOL(R) coolant into a clean container.
49. Using a clean funnel, pour as much of the 100% DEX-COOL(R) coolant that you can into the engine through the thermostat opening.
50. Install a new thermostat, GM P/N 12563335.
Tighten
Tighten the bolt to the specified torque of 19 N.m (14 lb ft).
51. Hold the upper radiator hose in the straight up position and pour 0.2366 L (1 pint) of the 100% DEX-COOL(R) coolant into the hose.
52. Install the upper radiator hose to the radiator and properly position the clamp.
53. Flush the coolant recovery bottle thoroughly.
54. Complete the fill of the cooling system with the balance of the 5.7 L (6 qt) of 100% DEX-COOL(R) coolant and top off with plain water. If the water is not drinkable, do not use. Water must be clean and fresh.
Important:
The second new radiator cap must be installed at this point of the procedure. It is possible that small contaminants may have become lodged in portions of the first cap during the cleaning procedure.
55. Clean the radiator cap sealing surfaces on the radiator. Install the radiator cap, GM P/N 15075565.
Important:
It is imperative that all air pockets have been removed in order for the cooling system to function properly.
56. Run the engine to operating temperature with the air conditioning in the maximum cool position for ten minutes.
Caution:
As long as there is pressure in the cooling system, the temperature can be considerably higher than the boiling temperature of the solution in the radiator without causing the solution to boil. Removal of the radiator cap while the engine is hot and pressure is high will cause the solution to boil instantaneously - possibly with explosive force - spewing the solution over the engine, fenders and the person removing the cap. Under some conditions, the engine coolant is combustible.
57. Turn the engine "OFF" and let it cool.
58. Check the coolant concentration for a 50/50 mix, using refractometer J26568 (Centigrade scale) or J23688 (Fahrenheit scale). Follow the manufacturer's directions for using the coolant tester. Unless your coolant tester has a provision for temperature correction, it is imperative that the correct coolant temperature is achieved when testing the coolant. If the coolant is warmer or cooler, the reading may be incorrect.
59. Top off the radiator and fill the coolant recovery bottle to 2.54 cm (1 in) above the full hot mark on the coolant reservoir. Add the appropriate coolant mixture to come to a 50/50 mix of the DEX-COOL(R) coolant.
Important:
To assure intended system performance, inform the customer that the cooling system MUST be maintained in a completely full condition.