However, if you're determined to do it yourself, here's a *general* outline. Specific procedures will vary depending on the engine (4.3L V6, 5.7L V8, etc.) in your Blazer. You MUST consult a repair manual specific to your Blazer's year and engine type. A Haynes or Chilton manual is a good investment.
1. Preparation is Key:
* Safety First: Disconnect the negative battery terminal. Wear safety glasses and gloves. Work in a well-ventilated area.
* Gather Tools and Supplies: You'll need a comprehensive set of tools, including various sockets, wrenches, screwdrivers, a torque wrench, a head gasket set (including the gasket itself, head bolts, and possibly other components), engine hoist or jack stands, coolant drain pan, and possibly a gasket scraper.
* Consult Your Repair Manual: This is crucial. The manual will provide specific torque specifications, bolt removal order, and other critical information. Deviating from these can lead to warped heads or other damage.
* Clean the Engine Bay: This will make the process easier and prevent dirt from falling into the engine.
2. Removal Process (General Steps – Consult your manual for specifics):
* Drain Coolant and Oil: Completely drain the engine's coolant and oil.
* Disconnect Components: Disconnect all components connected to the cylinder head, including:
* Spark plug wires
* Fuel injectors (if applicable)
* Intake manifold
* Exhaust manifold
* Valve cover(s)
* Sensors and wiring harnesses
* Remove Accessories: Remove any accessories that might interfere with head removal (e.g., power steering pump, alternator).
* Remove the Cylinder Head: This is the most physically demanding part. You'll likely need to remove the rocker arms, pushrods, and potentially other components. You'll almost certainly need an engine hoist or strong jack stands to support the head as you remove the bolts. Follow the specific bolt removal order in your repair manual precisely to avoid warping the head.
* Inspect the Head Gasket: Carefully examine the old head gasket for signs of failure (blown areas, leaks, etc.).
* Inspect the Cylinder Head: Check the cylinder head for cracks or warpage. Warpage can prevent a new gasket from sealing properly.
* Clean the Head and Block: Thoroughly clean the mating surfaces of the cylinder head and engine block. Use a gasket scraper to remove any old gasket material.
3. Installation (General Steps – Consult your repair manual for specifics):
* Install New Head Gasket: Carefully install the new head gasket, ensuring it's properly aligned.
* Install the Cylinder Head: Carefully lower the cylinder head onto the engine block, making sure it's properly seated.
* Tighten Head Bolts: This is extremely critical. Tighten the head bolts in the precise sequence and to the specified torque values indicated in your repair manual. Using the wrong torque can cause head gasket failure or worse. A torque wrench is absolutely essential.
* Reconnect Components: Reconnect all the components you removed earlier, in reverse order.
* Re-fill Fluids: Refill the engine with coolant and oil, checking levels carefully.
* Start the Engine: Start the engine and check for leaks. Let the engine run for a while to ensure everything is working properly.
4. Post-Repair:
* Check for Leaks: Carefully inspect for any coolant or oil leaks.
* Check Fluid Levels: Monitor fluid levels for a few days to ensure no further leaks develop.
Again, this is a very general outline. You absolutely must obtain and carefully follow a repair manual specific to your 1999 Chevy Blazer's engine. Attempting this repair without the proper knowledge and tools can lead to costly mistakes. If you are unsure about any step, please seek professional help.
