Repair Procedure A & B
Important:^ If available, use coolant exchanger Pro-Fill 42-75100-KM, Power Flush 211-07601/DEX (available through the GM Dealer Equipment program), or equivalent to evacuate the system of coolant. Follow the manufacturer's instructions for exchanging used coolant with new coolant. However, for this procedure, use water in place of new coolant. Be sure to exchange 1-1/2 times the cooling system capacity of the vehicle with water. This will ensure that only water remains within the cooling system. Once the coolant has been displaced with water, drain the water from the radiator.
^ If you are located within an area which regulates the disposal of used coolant (check with your local water treatment facility), all coolant and coolant (water mixture must be captured until the water runs clear of coolant. Use a clean 208 L (55 gal) drum or similar to contain the waste coolant. Refer to Corporate Bulletin Number 00-06-02-006 for information on coolant recycling and removal services.
1. Drain and properly dispose of the coolant.
Caution:
Any obstructions in the hoses to or from the coolant recovery bottle may cause over pressurization of the cooling system. This over pressurization could result in serious personal injury.
2. Inspect the following hoses in order to assure there are no obstructions and the coolant is able to flow freely:
^ The hose to the coolant recovery bottle.
^ The relief hose from the coolant recovery bottle.
3. Disconnect both coolant hoses to the heater core from the engine.
4. Back flush the heater core for 5 minutes after clear water is present. Pressurized water not to exceed 345 Kpa (50 psi), may be used.
5. Reinstall the heater return hose to the engine.
6. Install the radiator cap and properly tighten.
7. Install the "T" from the flush and fill kit to a 25.4cm (10 in) piece of 19 mm (1/4 in) heater hose. Tighten the clamp.
8. Install the hose to the engine. Tighten the clamp.
9. Install the other end of the "Tin the heater core inlet hose. Tighten the clamp.
10. 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.
11. If you used coolant exchange equipment, disconnect it.
12. 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.
13. Start the engine and continue back flushing the cooling system for five additional minutes.
14. Turn the engine "OFF".
15. Turn the water "OFF".
16. Re-attach the upper radiator hose to the radiator.
17. Open the radiator drain and drain all water from the radiator.
18. Remove the lower left water pump crossover bolt. This allows lowering the water level in the left side of the engine.
19. After the water stops running from the water pump bolt hole, reinstall the bolt.
20. Close the radiator drain.
21. Mix the Prestone(R) Heavy Duty Cooling System Cleaner, GM P/N 12346500, in approximately 3 L (3 qt) of warm water. Pour the mixture into the radiator. Top off the system with plain water and reinstall the radiator cap.
22. Run the engine at 1600 to 1800 RPM with the air conditioning in the maximum cool position.
To achieve the 1600 to 1800 RPM, place a dime between the closed throttle stop and the screw. This screw should never be adjusted, under any circumstance. Its only purpose is to keep the throttle plate from sticking in the bore when the throttle is slammed shut. It is not a minimum idle (RPM) control adjustment screw.
Important:
It is imperative that all air pockets have been removed from the cooling system in order for the cleaning procedure to be effective.