Fitting core plugs, freeze plugs or welch plugs in situ

[Virtus]

Looking for advice. My 1921 TT is weeping from the core plugs.Is it possible to replace them in situ, I.e. without removing the inlet or exhaust manifolds?. Any advice or opinions would be appreciated, thanks.

[John kuehn]

Removing the manifolds is the best way to do it. It’s pretty simple to do. It will give you more room to do the job. You can use a screwdriver to pop the old freeze plugs out. Use a hammer to drive it in and then prey them out. Once out use a knife or a screwdriver and clean out the holes. You can order some brass plugs from the suppliers or you can use a nickel from your pocket. Or as some like to do use a Buffalo nickel if you want to be period correct!
Place the nickel on the top of a right size socket and use a ball pein hammer to make a dimple in it. Use some sealer if you want and tap in the nickel and gently flatten it out. Your good to go.
While your at it get some new manifold gaskets preferably the ring type. You will need to get some to do a complete job.

[Kerry]

Yes, can be done with out removing the manifolds.
Might be a bit hard to find a Nickel at your end of the world so stick with the brass expansion plugs.

[Virtus]

Thanks John, I was trying to avoid disturbing the manifolds, or worse still, shearing the studs which are badly corroded! I have sourced some brass plugs as nickels are pretty scarce in the U.K.!

[Virtus]

Thanks Kerry, brass plugs already purchased!

[speedytinc]

The new brass freeze plugs need more crown to make em small enough to go in. Place in a socket just big enough to support. Lay the ball end of a medium pall peen hammer on top. Hit the flat side with a mallet or put in a press. You should have straight access to set. Back one is a bit more difficult to set.

[Virtus]

Core plugs fitted this morning without removing any manifolds. A test run was needed to check for leaks. I thought it best to kill two birds with one stone by driving to the "Local Hostelry" for a pint of Guinness. As you can see there are no puddles on the carpark , success.
Thanks for all the advice, another skill mastered!