Core Plug replacement

[COMMERCIALMAN]

Hi All, Could someone tell me what is the best way to replace a core plug. The faulty one is out but the replacement has convex concave sides and im uncertain what way it should go in. Also what sealent should i use on it. I did try to fit it but when i filled the rad the water pushed the core plug out.
Regards
Jason

[charlie_morris_minor]

the concave goes on the inside the convex side is therefore on the outside..

did you bash it in the centre once you had put it into place ( forgive me if that is a stupid question I do not mean to offend you ) as you should not need any sealent..

[bmcecosse]

The hole has to be spotlessly clean - and yes as above - convex out and then you hammer it in - collapsing the convex shape to make the plug grip the hole. In theory no sealant - but after these years and possibly a little corrosion - I would advise a wipe of hermatite gold or similar around the hole before placing the plug - and then wipe away excess after the hammering!

[COMMERCIALMAN]

Thanks for that guys . I think i wasnt giving it enough welly. I did have in round the right way. The sealeant i was using in hylomar blue, think thats want it is called .
Jason

[bmcecosse]

Hylomar is very thin - hermy gold is nice and thick! But really - it shouldn't need any - it's just there to fill in any little rust pits that may weep around the plug.

[autolycus]

Just to add to the good advice already given in case anyone else is doing the job: either use the ball end of a ball-pein hammer, or, perhaps easier for the inexperienced or where access is tricky, use a rounded end punch around a third to half the diameter of the core plug. You're aiming to flatten or perhaps slightly invert the curvature in the centre of the plug until it expands and grips, not necessarily to get it completely flat. It's amazing what you can mash with the other end of the hammer while you're concentrating on hitting the core plug.

Some engines use core plugs with a flat centre and short, raised walls. Easier to put in, but less tolerant of corroded blocks without a smear of sealant.

Kevin

[bmcecosse]

It is bound to be difficult to get a decent swing at it - with the engine in the car.........