How to Fix a Head Gasket with Block Sealer
- 1). Set the shifter in park, for an automatic transmission. Place the shifter in neutral, for a manual transmission. Apply the emergency brake. Use a floor jack to lift the front of the vehicle and place two jack stands under the frame. Raise the rear of the vehicle and place two jack stands under the rear frame. Make certain all the jack stands sit at the same elevation so the vehicle sits level.
- 2). Raise the hood. Remove the radiator cap. Place a drain pan under the radiator drain petcock valve. Use pliers or your fingers to turn the petcock valve clockwise to open it. Let the radiator coolant drain in the pan. Shut the petcock valve by turning it outward, counterclockwise.
- 3). Use your owner's manual to locate the engine block drain plugs on your vehicle, if so equipped. The drain plug will be located on the lower side of the engine block and have a hex socket head or a four-sided plug head. Place the drain pan under the plug and use a socket or spanner wrench to loosen and remove the plug. Let the coolant drain, then replace and tighten the plug with the appropriate tool.
- 4). Loosen the lower radiator hose clamp with a screwdriver and pull the hose from the radiator. Let any coolant drain into the drain pan. Push the hose back on the radiator neck and tighten the clamp with the screwdriver. Use a turkey baster to remove all of the coolant from the plastic overflow reservoir tank.
- 5). Place the drain pan under the radiator petcock drain valve. Fill the radiator with plain water from a garden hose. Start the engine, with the radiator cap off. Turn the vehicle heater on to its maximum setting. Before the engine gets too warm, place a garden hose inside the radiator neck.
- 6). Turn the hose on, allowing a small stream of water to enter the radiator. Open the radiator petcock drain valve with pliers or your fingers, letting the water drain into a pan. Adjust the hose pressure so the radiator remains full at the top while it drains from the petcock valve. Let the engine run until all the green or orange-colored coolant has drained into the pan. Remember to switch drain pans when one has filled.
- 7). Close the petcock valve when only clear water exits the drain valve. Shut off the engine and the hose. Pour a can of block sealer into the radiator, according to directions. Replace the radiator cap. Use the floor jack to remove all the jack stands. Shut the hood.
- 8). Drive the vehicle for 500 miles, with nothing but fresh water and the block sealer mixture in the radiator. After 500 miles, place a drain pan under the radiator petcock valve. Open the valve with pliers or your fingers (on a cool engine). Drain approximately 50 percent of the water from the radiator then close the petcock valve. Open the radiator cap and fill the radiator with coolant. Replace the cap.
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