Core Plug Replacement

Core Plug Replacement









NOTICE: It is necessary to use High Temperature Retaining Compound on all cylinder head core plugs. If not used, the cylinder head core plugs could leak or seep, causing serious engine damage.

NOTE: Use threadlock 262 on all other applications.

1. NOTE: Cylinder block core plug shown, cylinder head core plug similar.

NOTE: On cylinder head core plugs, do not put the pilot hole in the center of the core plug. Rather put the pilot hole to the side of the center line of the core plug.

NOTE: Do not use a drill bit for the pilot hole, use a awl to make the pilot hole.

Using the Slide Hammer and a commercially available body dent puller attachment or commercially available freeze plug puller, remove the core plug.





2. Inspect the core plug bore for any damage that would interfere with the correct sealing of the plug. If the core plug bore is damaged, bore for the next oversize plug.

3. NOTICE: Use care during this procedure so as not to disturb or distort the cup sealing surface.

NOTE: The insertion arbor should be 0.5-0.75 mm (0.020-0.029 in) diameter less that the inner diameter of the core plug. The insertion pressure will then be exerted as close as possible to the vertical wall and still permit the removal of the arbor after core plug installation.

NOTE: The insertion end of the arbor should be flat so it does not press on the crown portion of the core plug causing the vertical wall to pull away from the inner diameter of the hole.

NOTE: The insertion edge of the arbor should have a radius matching the inner diameter radius of the core plug. This will prevent the arbor from hitting the inner diameter radius of the core plug, causing expansion that would be detrimental to proper sealing.

NOTE: Under no circumstances should a core plug be driven by exerting pressure on the trimmed edge. This prevents the proper flow of material and increases the probability of the crooked insertion of the core plug into the hole.

NOTE: When installed, the flanged edge must be a minimum of 0.75 mm (0.029 in) below the chamfered edge of the bore to effectively seal the bore.

Coat the cup-type core plug and bore lightly with sealant and install the core plug using a freeze plug installer.

- Remove the excess sealant after installation.