freeze pluv

[chargerdon]

On my 66 charger with 383 Freeze plug on drivers side next to starter is leaking.   Took it out and measured with digital caliper and it goes 1.625 outside diameter and shallow (about .3) deep.     
Trouble is all of the part stores show either 1.64 Dorman 555-068 or 1.701 diameter freeze plugs.   No one shows 1.625 which is 1 and 5/8.)

I bought 2 of the Dorman 555-068 (1 and 41/64  i.e 1.64 plugs and try as i might i cant drive them in.  I once put one in freezer for 1 hour and tried but still cant drive it in using a 1 1/4 in socket to drive. 

Napa does list a brass sealed power 1.625 plug but its a deep (.5) plug and they are permanently out of stock.  Also amazon lists a brass Dorman 565-030 or Dorman 550-030 steel plug Dorman at 1.625 but their also in a deep (.5plug)   

Should i get the Dorman 1.625 plug ?  Will the extra depth hurt anything ?

Am i missing something?

[pschlosser]

The plugs, or cups, are usually tapered some, but look for one designed for the opening you want.  The plugs are usually sold in kits, but you can buy them individually, often enough.  Don't over pay.  These are cheap stamped metal parts, not space shuttle SRB parts.

They are domed, and can measure 1/2-inch in total height, but that doesn't mean the lip porting is 1/2-inch high.  You got the diameter correct, 1-5/8, and brass may last (decades) longer than steel.  Chances are, petrol fuel will dry up before the new one has a chance to rust away.

You want the plug to be seated in there so it's flush, or below the outer surface of the block.  Coolant DOES flow behind it, but also around it.  If you get one too deep, it may be hard to remove it (with the pivot technique)

If you have one failing, another may not be far behind, so consider a whole kit.

https://www.amazon.com/Milodon-34041-Brass-Freeze-Chrysler/dp/B0050VKU68

[Bullitt-]

appears Melling makes what your looking for
https://www.summitracing.com/search/part-type/engine-expansion-plugs?fr=part-type&SortBy=BestKeywordMatch&SortOrder=Ascending&keyword=MPS-126


Brand:
Melling
Manufacturer's Part Number:
MPS-126
Part Type:
Engine Expansion Plugs
Product Line:
Melling Freeze Plugs
Summit Racing Part Number:
MEL-MPS-126
UPC:
729295610908
Expansion Plug Material:
Steel
Outside Diameter (in.):
1.625
Depth (in.):
0.365 in.
Quantity:
Sold individually.

[chargerdon]

Sigh...   I call mellings hot line and spoke with what seemed to be a very knowledgeable assistant.   

He said that yes once installed and removed a freeze plug would measure 1.625, but that it started life before being installed at 1-41/64...i.e.  1.64.  He said do not install cups that measure 1.625 before install or you will risk them easily being blown out. 

He understood how difficult it can be to get a "good" strong straight blow to install properly but that it can be done.  If the engine were out of the car it would go easy.  He also recommended using brass (not because of the longer life) but that they compress in a little easier.   

Has anyone ever used any of the rubber plugs with a bolt to make them expand so that i dont have to worry about pounding it iN.   Only need one for each side as the others are good.  If so can someone recommend one ?   

Anyone ? 

[Jay Bee]

Well, being curious myself I did a Google search: "rubber freeze plug reliability". A quick read through and it looks like a hit or miss, kind of a 50/50. Some of the posts that had a blowout wondered if theirs were tight enough or if using locktite on the threads would have made a difference. Of course there were several, "just put a brass one in".

[EV2RTSE]

One of the freeze plugs gave out on my 340 some years ago, of course it was one of the more difficult ones to reach between the back of the block and the transmission. Decided to just pull the engine and replace them all. Found there were a couple of others that looked ok from the outside but were in bad shape on the inside. And I also had a similar issue with one of the plugs in the kit, it was thicker than the one it was replacing. In my case I think it was one in the cylinder head. I figured if the factory made the plug a certain size they did it for a reason so better to play it safe and match it, I ordered one from Melling that was the right size.

[tparker]

I just put in a bunch of brass ones into my Jeep 4.0. It took a good deal of force to install them. Not a ridiculous amount but they need a bit or persuading. I can see it being a pain to do it in the car. I used a seal driver that was a bit bigger than the plug with a bit of aviation gasket sealer I think. I drove it in with a small sledge hammer. The first one I wasn't sure how much effort to use so  I played with it for a little bit. The rest went in pretty easily with a few good whacks.

[chargerdon]

success i think. Friday after speaking with a Melling support person he explained to me that the reason the plug i took out measures 1.625 is that that is the size of the HOLE. When the plug is pounded into it i shrinks down to the hole size, and that yes 1-41/64 (1.64 is the size plug to use). He also told me that he understands it can be difficult and that brass plugs go in a LITTLE easier.

So if bought from Oreillys Dorman 565-030 Brass plugs. I measured these plugs and they were 1.637 or a tiny bit smaller than the steel plugs. Put them in the freezer overnight, and then used a heat gun on the block for about 2 mins, and put the plug with Ford gasket sealer which is a thick liquid around the plug . Had a friend help me as i held my socket in the plug and hanging down with extensions below the torsion bars pound it with a 2lb sledge. Took about 5 blows to go in far enough. Then repeated the process on the freeze plug on passenger side and it to went right in.

Today ill fill with plain water and run till up to temp and check for hopefully no leaks. Then drain radiator and add anti freeze.