GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1996 🢒 Astro - 4WD 🢒 Engine 🢒 Engine Electrical 🢒 Cooling System Draining and Filling

Engine Coolant Recycling

Tools Required

GM approved Recycling System such as Pro Clean (Available in the GM Dealer Equipment Program)

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.

    • 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, use DEX-COOL® coolant. If silicated coolant is added to the system, premature engine, heater core or radiator corrosion may result. In addition, 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 radiator drain cock.

    3. Object Number: 4314 Size: SH
  3. Install a tube on the radiator drain. Place the end of the tube in the drain pan.
  4. After the engine cools down, remove the radiator cap. Refer to Radiator Filler Cap Assembly .
  5. Completely open the radiator drain cock.
  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. There may be more drainage from the radiator at this time.
  10. Install the block drain hole plug.
  11. Close the radiator drain cock.

Filling Procedure
  1. Check to make sure that the radiator drain cock is closed.
  2. Check to make sure that the block drain hole plug is tight.
  3. Premix a 50/50 solution of antifreeze and clear, preferably distilled water. If you use the old coolant, make sure the solution is clean and clear, and that the solution is a 50/50 mixture of glycol and water.
  4. Place a large top funnel in the radiator filler neck.
  5. Slowly pour in the coolant. Refer to Fluid Capacity Specifications . Because the thermostat is closed, filling the cooling system may be slow.
  6. After you fill the cooling system to 13 mm (½ in) below the radiator filler neck, 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 to just below the filler neck.
  7. Install the radiator cap.
  8. Check the coolant level in the coolant recovery reservoir. Add coolant as necessary.