[Warrant]

What do you guys use to seal on freeze plug and the oil galley plugs like the 3 front ones? Same stuff that you use to seal the threads on head bolts??

Perematex super hi tack?
Form a gasket?
Lock tite?

[MrBill66Malibu]

I use HiTack on the freeze out plugs and blue thread lock on oil galley plugs

[Erics69]

I use Permatex Form a gasket sealent "Super 300" part # 83H.

[pdq67]

Good old Permatex, "Indianhead Shellac Gasket Cement"!!

pdq67

[engineguy]

The freeze plug manufacturers recommend that you do not use any sealant when installing the plugs. Make sure the holes are clean and rust free. A slight amount of light weight oil can be applied to the hole and the plug to make installation easier. The most important thing is HOW you install the plugs. Cup-type plugs should be installed with an installation tool (or a large socket). The plug should be driven by the inside of the cup, never by the sides of the cup.
The threaded plugs can be installed with any thread sealer, applied sparingly to clean/dry plugs.

[novaderrik]

any sealer you put on the plug will get pushed right off when you push it into the hole.

[Tom Mobley]

>> "any sealer you put on the plug will get pushed right off when you push it into the hole."

unless there's pits and gouges from rust and previous R&R.

those manufacturers, wonder if they work on 40 year old blocks much?

I put a thin wipe of RTV in the ID of the hole, drive the plugs in with a large socket that just barely fits in the plug. That's thin wipe as in see-through, wait at least 5 minutes before driving the plug in. You want the RTV to be exposed to air a few minutes so the chemical process of curing has a decent chance to get started.

[engineguy]

those manufacturers, wonder if they work on 40 year old blocks much?

Excellent observation . . . . . . and yes, they do.

My contact with freeze/expansion/core/Welch plugs was during my tenure in the Product Planning department of one of the largest (OEM & aftermarket) automotive parts manufacturers in the industry. Our concern was exactly the same as yours and we were (and still do) field many calls concerning expansion plug failure. We all know that these plugs are installed in bores that may be of questionable physical condition and the installation process is possibly undertaken in the very poorest of conditions (like underneath a tractor in the middle of a field).

The consensus of the plug manufacturers (who supply both the OEM and aftermarket) was that the hole must be cleaned and dried as well as possible before installation. The affect of any type of sealer is totally useless even if there are pits in the bore. Severe pitting and gouges should be treated with corcus cloth or sandpaper, but if the plug is going to fail it will do so whether or not sealer (goop) is used in the installation.

Just reporting the facts . . . .

[SWHEATON]

What Paul said,you cant go wrong with "INDIAN HEAD SHELLACK" ,its a little messy at times but it's a very reliable sealer when properly used meaning ensure all sealing surfaces are clean of oil residue etc prior to sealing.

Scott

[racecar100]

I use loctite and never had any problem even using 24 pounds radator cap.