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Engine Cooling System: Maintenance Chevrolet Silverado 2500 HD

Cooling System (Mechanical) ~746 words

Cooling System Draining and Filling (Static Fill)

Tools Required

  1. J 26568 Coolant and Battery Tester. See «Special Tools»(ref-277993-S07049521082008012100000) .
  2. J 38185 Hose Clamp Pliers. See «Special Tools»(ref-277993-S07049521082008012100000) .

Draining Procedure

CAUTIONTo avoid being burned, do not remove the radiator cap or surge tank cap while the engine is hot. The cooling system will release scalding fluid and steam under pressure if radiator cap or surge tank cap is removed while the engine and radiator are still hot.
  1. Follow the steps below in order to remove the surge tank fill cap: Slowly rotate the cap counterclockwise. Stop rotating and allow the hissing to stop. After all the hissing stops, continue turning counterclockwise in order to remove the cap.
  2. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(ref-278014-S01448585812008012100000) .
  3. Place a drain pan under the lower radiator hose.
  4. Using the J 38185 , reposition the lower radiator hose clamp. See «Special Tools»(ref-277993-S07049521082008012100000) .
  5. Remove the lower radiator hose from the radiator.
  6. Drain the cooling system.
  7. If a complete engine block drain is required, remove the left and right engine block coolant drain plugs.
  8. Remove the engine block coolant heater, if equipped. Refer to «Coolant Heater Replacement (L76, L92)»(ref-277993-S23864057872008012100000) or «Coolant Heater Replacement (LH6, LY2, LMG, LY5, and LY6)»(ref-277993-S07968145002008012100000) or «Coolant Heater Replacement (LU3)»(ref-277993-S04347628872008012100000) or «Coolant Heater Replacement (LMM)»(ref-277993-S35384070082008012100000) .
  9. Inspect the coolant.
  10. Follow the appropriate procedure based on the condition of the coolant: Normal in appearance-Follow the filling procedure. Discolored-Follow the flush procedure. Refer to «Flushing»(ref-277993-S21530991802008012100000) .

Cooling System Draining and Filling (Vac-N-Fill)

Tools Required

  1. J 26568 Coolant and Battery Tester. See «Special Tools»(ref-277993-S07049521082008012100000) .
  2. GE-47716 Vac-N-Fill Coolant Refill Tool. See «Special Tools»(ref-277993-S07049521082008012100000) .
  3. J 42401 Radiator Cap and Surge Tank Test Adapter. See «Special Tools»(ref-277993-S07049521082008012100000) .
CAUTIONWith a pressurized cooling system, the coolant temperature in the radiator can be considerably higher than the boiling point of the solution at atmospheric pressure. Removal of the surge tank cap, while the cooling system is hot and under high pressure, causes the solution to boil instantaneously with explosive force. This will cause the solution to spew out over the engine, the fenders, and the person removing the cap. Serious bodily injury may result.
  1. Park the vehicle on a level surface.
  2. Remove the coolant pressure cap.
  3. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(ref-278014-S01448585812008012100000) .
  4. Place a drain pan under the drain cock.
  5. Open the radiator drain cock.
  6. Drain the cooling system.
  7. If a complete engine block drain is required, remove the engine block drain plug.
  8. Inspect the coolant.
  9. Follow the appropriate procedure based on the condition of the coolant. Normal in appearance-Follow the filling procedure. Discolored-Follow the flush procedure. Refer to «Flushing»(ref-277993-S21530991802008012100000) .

Vac-N-Fill Procedure

IMPORTANTTo prevent boiling of the coolant/water mixture in the vehicles cooling system, do not apply vacuum to a cooling system above 49°C (120°F). The tool will not operate properly when the coolant is boiling.
  1. Install the J 42401 . See «Special Tools»(ref-277993-S07049521082008012100000) .
  2. Attach the Van-N-Fill cap to the vehicles coolant fill port.
  3. Attach the vacuum gage assembly to the Vac-N-Fill cap.
  4. Attach the fill hose to the barb fitting on the vacuum gage assembly. Ensure that the valve is closed.
  5. Pour the coolant mixture into the graduated reservoir.
  6. Place the fill hose in the graduated reservoir.
  7. Install the vacuum tank on the graduated reservoir with the fill hose routed through the cut-out area in the vacuum tank.
  8. Attach the venture assembly to the vacuum tank.
  9. Attach a shop air hose to the venture assembly. Ensure the valve on the venture assembly is closed.
  10. Attach the vacuum hose to the vacuum gage assembly and the vacuum tank.
  11. Clamp off the overflow hose.
  12. Open the valve on the venture assembly. The vacuum gage will begin to rise and a hissing noise will be present.
  13. Continue to draw vacuum until the needle stops rising. This should be 610-660 mm Hg (24-26 in Hg). Cooling hoses may start to collapse. This is normal due to vacuum draw.
  14. To aid in the fill process, position the graduated reservoir above the coolant fill port.
  15. Slowly open the valve on the vacuum gage assembly. When the coolant reaches the top of the fill hose, close the valve. This will eliminate air from the fill hose.
  16. Close the valve on the venture assembly.
  17. If there is a suspected leak in the cooling system, allow the system to stabilize under vacuum and monitor for vacuum loss. If vacuum loss is observed, refer to «Loss of Coolant»(ref-277993-S42443381422008012100000) .
  18. Open the valve on the vacuum gage assembly. The vacuum gage will drop as coolant is drawn into the system.
  19. Once the vacuum gage reaches zero, close the valve on the vacuum gage assembly and repeat steps 11-17.
  20. Remove the J 42401 . See «Special Tools»(ref-277993-S07049521082008012100000) .
  21. Detach the Vac-N-Fill cap from the vehicles coolant fill port.
  22. Add coolant to the system as necessary.
  23. Inspect the concentration of the coolant mixture using J 26568 . See «Special Tools»(ref-277993-S07049521082008012100000) .
  24. Detach the vacuum hose form the vacuum gage assembly.
  25. Attach the extraction hose to the vacuum hose.
  26. Open the valve on the venture assembly to start a vacuum draw.
  27. Use the extraction hose to draw out coolant to the proper level.
  28. The vacuum tank has a drain valve on the bottom of the tank. Open the valve to drain coolant from the vacuum tank into a suitable container for disposal.

Flushing

IMPORTANTDo not use a chemical flush. Store used coolant in the proper manner, such as in a used engine coolant holding tank. Do not pour used coolant down a drain. Ethylene glycol antifreeze is a very toxic chemical. Do not dispose of coolant into the sewer system or ground water. This is illegal and ecologically unsound. Various methods and equipment can be used to flush the cooling system. If special equipment is used (such as a back flusher) follow the manufacturer's instructions. However, always remove the thermostat before back flushing the system. Block the drive wheels. Place the transmission in park (P) or neutral (N). Engage the park brake. Run the engine until the thermostat opens. Stop the engine. Follow the drain and fill procedure unsing only clean drinkable water. Repeat the procedure if necessary, until the fluid is nearly colorless. Refer to Cooling System Draining and Filling (Static Fill) or Cooling System Draining and Filling (Vac-N-Fill) . Fill the coolant reservoir to the FULL HOT mark. Fill the cooling system. Refer to Cooling System Draining and Filling (Static Fill) or Cooling System Draining and Filling (Vac-N-Fill) .

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