Here's a step-by-step guide:
1. Gather Your Supplies:
* New coolant: Use the correct type for your Blazer. Check your owner's manual for the recommended type (usually a 50/50 mix of coolant and distilled water). Never use tap water.
* Drain pan: Large enough to hold several gallons of coolant.
* Wrench: For the drain plug (likely a 1/2" or 9/16" wrench).
* Funnel: To avoid spills when refilling.
* Hose clamps (optional but recommended): If you plan to replace the lower radiator hose.
* New lower radiator hose (optional): Consider replacing this while you're at it. They degrade over time.
* Gloves: To protect your hands from the coolant.
* Safety glasses: To protect your eyes from splashes.
* Jack and jack stands (recommended): For easier access to the drain plug. Never work under a vehicle supported only by a jack.
2. Prepare the Vehicle:
* Park the Blazer on a level surface and engage the parking brake.
* Allow the engine to cool completely. The radiator cap can be extremely dangerous if opened on a hot engine.
* Locate the radiator drain plug. It's typically at the bottom of the radiator, usually a bolt or petcock.
3. Drain the Coolant:
* If using a jack: Raise the front of the Blazer and securely place it on jack stands.
* Position your drain pan under the radiator drain plug.
* Carefully open the radiator cap (once the engine is completely cool). Some pressure might still be present, so proceed cautiously. A slow release is better than a sudden burst.
* Loosen and remove the radiator drain plug. Let the coolant drain completely. This can take some time.
4. Drain from the Engine Block (Important):
* Many vehicles, including your Blazer, have a drain plug on the engine block as well. Locate this plug (consult your owner's manual if needed) and drain the coolant from the engine block into the drain pan. This step is crucial to removing almost all the old coolant.
5. Optional: Flush the System (Recommended):
* For a more thorough cleaning, after draining, fill the radiator with clean water and run the engine for 10-15 minutes. Then drain the water. Repeat this process 2-3 times to flush out any remaining old coolant and debris.
6. Replace the Drain Plugs:
* Once drained, replace the radiator and engine block drain plugs, tightening them securely.
7. Refill the Radiator:
* Using your funnel, carefully pour the pre-mixed coolant (or the correct mix of coolant and distilled water) into the radiator until it's about an inch from the top.
8. Bleed the Air:
* This is critical! Air bubbles in the cooling system can cause overheating. Run the engine for a few minutes with the radiator cap OFF (to allow air to escape). Check the coolant level and add more as needed. Once the thermostat opens (you'll see a change in temperature gauge), close the radiator cap.
* Some Blazers have a bleed valve. Consult your owner's manual. If you have a bleed valve, carefully open it while the engine runs to let air out, then close it once coolant starts flowing.
9. Top Off and Check:
* With the engine off and cool, check the coolant level in the radiator and overflow tank (surge tank). Add coolant as needed to bring it to the proper level.
10. Run the Engine and Check for Leaks:
* Start the engine and let it run for a while, monitoring the temperature gauge. Check for any leaks around the drain plugs, hoses, and radiator.
11. Final Check:
* After running the engine, let it cool down completely, and check the coolant level again. Top off if necessary.
Important Notes:
* Consult your owner's manual: This guide provides general information. Your owner's manual will have specific instructions for your 2001 Chevy Blazer LS.
* Professional Help: If you're not comfortable performing this task yourself, take your Blazer to a qualified mechanic.
This is a complex procedure, and mistakes can lead to engine damage. If you're unsure about any step, seek professional help. Safety first!
