Core plug removal

[Wendy Dawes]

We suspect that Mabel has a leaking core plug, the one behind the manifold, it started leaking immediately after fitting a new water pump. Doesn’t seem to be head gasket as there’s no water ingress into the oil in the sump.   ( hope it’s not a cracked head won’t find out til manifold comes off)  

does anyone have any tips on the best way to remove the old core plug,  and any possible pitfalls to look out for 

Thankyou 

Edited July 12, 2022 by Wendy Dawes

[yorkshire_spam]

Depends a lot on luck... and the type of core plug.

I tend to start by drilling a small hole in the plug then screwing the very course threaded attachment for my slide hammer into the hole. The slide hammer rarely works, but when it does it's by far and away the quickest/easiest method I've found.

When that doesn't work, if the plug is the type with the lip edge I try and get a drift/chisel onto the edge and drive it inwards (similar approach to removing the outer part of a metalstic bush) 

When all else fails... just beat the thing out of shape and try and hook it out with a sturdy screwdriver.

 

[standardthread]

A large screwdriver punched through the centre of the plug, then pull and twist the screwdriver at an acute angle.

[Wendy Dawes]

30 minutes ago, yorkshire_spam said:

Depends a lot on luck... and the type of core plug.

I tend to start by drilling a small hole in the plug then screwing the very course threaded attachment for my slide hammer into the hole. The slide hammer rarely works, but when it does it's by far and away the quickest/easiest method I've found.

When that doesn't work, if the plug is the type with the lip edge I try and get a drift/chisel onto the edge and drive it inwards (similar approach to removing the outer part of a metalstic bush) 

When all else fails... just beat the thing out of shape and try and hook it out with a sturdy screwdriver.

 

Thanks the plugs are the lip edge type so I’m sure one of these methods will do it, don’t have a slide hammer though 😊

[Wendy Dawes]

13 minutes ago, standardthread said:

A large screwdriver punched through the centre of the plug, then pull and twist the screwdriver at an acute angle.

👍 thanks 

[yorkshire_spam]

1 minute ago, Wendy Dawes said:

Thanks the plugs are the lip edge type so I’m sure one of these methods will do it, don’t have a slide hammer though 😊

An alternative is a wide woodscrew and a crowbar with a claw end. (Or at a pinch a claw hammer)

[standardthread]

To replace it, a large block of wood across the diameter of the new plug to take the blows from the hammer, DON'T hit the centre of the plug.

[standardthread]

Can't edit the above again.

To make sure the plug is fully seated I use a large ball pien hammer as a drift with the flat face in the well of the plug gently tapping the ball with another hammer. Wear eye protection for this bit in case you strike a shard of metal off the ball, I have the scar on my arm to prove it.

On my spare engines and blocks (1960 Standard through to 1969 Herald) these plugs are lipped but Canley should provide the right type.   
 

[Wendy Dawes]

4 hours ago, yorkshire_spam said:

An alternative is a wide woodscrew and a crowbar with a claw end. (Or at a pinch a claw hammer)

👍

[Wendy Dawes]

3 hours ago, standardthread said:

Can't edit the above again.

To make sure the plug is fully seated I use a large ball pien hammer as a drift with the flat face in the well of the plug gently tapping the ball with another hammer. Wear eye protection for this bit in case you strike a shard of metal off the ball, I have the scar on my arm to prove it.

On my spare engines and blocks (1960 Standard through to 1969 Herald) these plugs are lipped but Canley should provide the right type.   
 

Thank you all advice much appreciated,  I know they can be a pain to do 😊

[Wendy Dawes]

4 hours ago, standardthread said:

To replace it, a large block of wood across the diameter of the new plug to take the blows from the hammer, DON'T hit the centre of the plug.

👍 I won’t I promise lol