GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2003 🢒 Astro - 4WD 🢒 Engine 🢒 Engine Controls - 4.3L 🢒 Cooling System Draining and Filling

Tools Required

    • GM approved Recycling System such as Pro Clean, available in the GM Dealer Equipment Program
    • J 38185 Hose Clamp Pliers

Engine Coolant Recycling

Whenever the cooling system needs maintenance or repairs, remove and replace the coolant with qualified new or recycled coolant.

If you only drain the radiator, up to 50 percent of the used, contaminated coolant can remain in the cooling system.

Use any of the following methods in order to remove the coolant:

    • Use a waterless coolant evacuation system, available in the GM Dealer Equipment program, or equivalent, that removes the used coolant and replaces the coolant with new or recycled coolant.
    • Use a GM approved coolant recycling system, available in the GM Dealer Equipment program, or equivalent, that recycles the coolant on the vehicle. This eliminates the need for coolant evacuation.

       Important: Do not recycle coolant on vehicles manufactured with GM Goodwrench® DEX-COOL® engine coolant.

    • Recover the used coolant. Store the coolant in a used coolant holding tank. Submit the used coolant for recycling on a regular basis.

Draining Procedure

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 pressure 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.

NOTICE: When adding coolant, it is important that you use GM Goodwrench DEX-COOL® or HAVOLINE® DEX-COOL® coolant. If Coolant other than DEX-COOL® or HAVOLINE® DEX-COOL® is added to the system the engine coolant will require change sooner; at 50 000 km (30,000 mi) or 24 months.

  1. Allow the engine to cool completely.
  2. Place a drain pan under the lower radiator hose.
  3. Using the J 38185 reposition the radiator inlet hose clamp from the radiator.
  4. Remove the radiator inlet hose from the radiator.
  5. Remove the radiator cap.
  6. Allow the coolant to drain from the system until the flow stops.
  7. Place a drain pan under the block drain hole plug.
  8. Remove the drain hole plug from the engine block.
  9. Allow the coolant to drain from the block until the flow stops.
  10. Install the block drain hole plug.
  11. Install the radiator inlet hose to the radiator.
  12. Using the J 38185 reposition the radiator inlet hose clamp to the radiator.

Filling Procedure
  1. Inspect that the block drain hole plug is tight.
  2. Place a large top funnel in the radiator filler neck.
  3. Slowly pour in a 50/50 mixture of DEXCOOL® and clean drinkable water.
  4. Start the engine and let the cooling system warm up. When the thermostat opens, the coolant level may drop. If the level drops, add coolant as needed.
  5. Install the radiator cap.
  6. Inspect the coolant level in the coolant recovery reservoir. Add coolant as necessary.