1956 coolant drain plug

[Willard M.]

One more of those 5 minute jobs that turns into a major problem. I tried to change the antifreeze in my 56 and took out the block coolant plug. Oops! It came out quickly and was not put in fully the last time. Is this 1/4 pipe thread? I hope to clean out the thread and replace the plug which is sh*t. Can I get this plug at my local NAPA? Anything else I should be aware of?

Bill #2659

[James F.]

Re: 1956 coolant drain plug

Bill, The fitting is pipe but I don't know my pipe fittings so I can't say what size it is it is. NAPA will have a replacement. Could use a brass pipe fitting if you wish. Reards,

[John H.]

Re: 1956 coolant drain plug

Bill -

Yup, they're 1/4" NPT plugs, same on both sides (you have to remove them on both sides, as the cylinder wall water jackets aren't cross-connected); use some anti-seize on them when you re-install them so you don't have to fight them next time.

[Joe L.]

Re: 1956 coolant drain plug

Bill-----

You can get 1/4" NPT plugs at most hardware stores, so you don't even need to go to an auto parts store (and, ask the counter guy for just a couple of pipe plugs). As Jim mentioned, if you get brass you'll avoid corrosion problems the next time (you were REALLY lucky to get these out easily; usually these are so tight that one risks cracking the block to get them out without resorting to heat). And, as John mentioned, I also recommend using anti-size on them even if you do use brass.

[Pierre J.]

Drain Plugs

I removed the original drain plugs on my '56 and replaced them with radiator drain plugs. Makes it simple and quick when I want to drain the cooling system. If you can get the radiator drain plugs with 1/2" extension for hose attachments, makes it even cleaner with no mess to clean up when you use them!!

Pierre (34410)

[Joe L.]

Re: Drain Plugs

Pierre------

Yes, from a purely functional perspective using petcocks in place of plugs works out well. There are 2 caveats, though:

1) they are more susceptible to damage or leaking than plugs; that's the reason that many new radiators have plugs for a drain rather than petcocks;

2) if original configuration is a concern, the petcocks are quite easily noted as being "non-original". The use of brass pipe plugs, though, while non-original, is no problem since these are painted with the block.