See Figures 1, 2 and 3
Core plugs need replacement only if they are found to be leaking, are excessively rusty, have popped due to freezing or, if the engine is being overhauled.
If the plugs are accessible with the engine in the truck, they can be removed as-is. If not, the engine will have to be removed.
- If necessary, remove the engine and mount it on a work stand. If the engine is being left in the truck, drain the engine coolant and engine oil
- Remove anything blocking access to the plug or plugs to be replaced.
- Drill or center-punch a hole in the plug. For large plugs, drill a 1 / 2 in. hole; for small plugs, drill a 1 / 4 in. hole.
- For large plugs, using a slide-hammer, thread a machine screw adapter or insert 2-jawed puller adapter into the hole in the plug. Pull the plug from the block; for small plugs, pry the plug out with a pin punch.
- Thoroughly clean the opening in the block, using steel wool or emery paper to polish the hole rim.
Coat the outer diameter of the new plug with sealer and place it in the hole:
For cup-type core plugs: These plugs are installed with the flanged end outward. The maximum diameter of this type of plug is located at the outer edge of the flange. Carefully and evenly, drive the new plug into place.
- Install any removed parts and, if applicable, install the engine in the truck.
- Refill the cooling system and crankcase.
- Start the engine and check for leaks.