REMOVAL & INSTALLATION
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 vehicle, 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 vehicle, drain the engine coolant and engine oil
- Remove anything blocking access to the plug or plugs to be replaced.
- Using a blunt tool such as a drift or a screwdriver and a hammer, strike the bottom edge of the cup plug.
Do not drive cup plug into the block assembly casting as restricted cooling can result.
- With the cup plug rotated, grasp firmly with pliers or other suitable tool remove the plug. For small plugs, pry the plug out of the engine block.
- 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 with a large socket-shaped tool, which fits snugly into the freeze plug.
- For expansion-type plugs: these plugs are installed with the flanged end inward. The maximum diameter of this type of plug is located at the base of the flange. It is imperative that the correct type of installation tool is used with this type of plug. Under no circumstances is this type of plug to be driven in using a tool that contacts the crowned portion of the plug. Driving in this plug incorrectly will cause the plug to expand prior to installation. When installed, the trailing (maximum) diameter of the plug MUST be below the chamfered edge of the bore to create an effective seal. If the core plug replacing tool has a depth seating surface, do not seat the tool against a non-machined (casting) surface.
- Install any removed parts and, if necessary, install the engine in the vehicle.
- Refill the cooling system and crankcase.
- Start the engine and check for leaks.