1937 Plymouth PT50 radiator petcock

[Grandpas37]

Hi all, 

 

Im new here and am just starting to revive my grandpas 37 Plymouth PT50.  We got in running 25 years ago and it was the last thing he drove before he passed. I was with him on that drive

 

Anyway, i wanted to flush the old coolant. Loosened the petcock, drained the coolant. But when i tried tightening back up, it still drips when closed.  i cranked a little more, but not too hard.  Leaked. Pulled it out and see a tiny little washer thats seen its better days.  This petcock doesnt look like the typical npt 1/4".  

 

Do you guys know where to find a replacement?

 

Oh, and Merry Christmas!

 

thanks!

[Grandpas37]

Well, looking around the internet, seems like some of these radiators had different drains.  Made me look at mine a little closer.  I see threads there.  So, im guessing that the petcock threads into the block and the block threads into the tube.  So, maybe that tube is threaded to receive 1/4 NPT?  Ill find out soon enough.

 

By the way, do any of you guys have this tube sticking out of your radiator?  Again, seems like ive seen a few flavors in my limited research.

 

thanks!

[kencombs]

I haven't seen one like that before.  It looks like the very end with the tapered part may seal against a seat that is machined into the the  housing. inside the if so, maybe some cleanup with some lapping compound is what it needs..  The washer looking item maybe an oring, can't tell from the pic.  If it is, it is probably a standard size.

 

Can you get a shot of the hole  or seat area?

 

If the leak is out of the drain hole, it is probably the seat.  If it around the handle or shaft it is probably the oring.

[Sniper]

that seal looks like packing ring, local hardware store might have something useable.

 

The packing is to seal the shaft of the valve at the nut, sort of like your garden hose outlet in the house or a sink faucet.

 

Only problem I see is that you may have to remove the handle from the stem and it's probably peened over. 

[kencombs]

19 hours ago, Sniper said:

that seal looks like packing ring, local hardware store might have something useable.

 

The packing is to seal the shaft of the valve at the nut, sort of like your garden hose outlet in the house or a sink faucet.

 

Only problem I see is that you may have to remove the handle from the stem and it's probably peened over. 

If it is a packing ring, not an oring, s little packing string is an easy fix.  finding a plumbing supply with it in stock may not be so easy.  reference  :

 info;  https://www.familyhandyman.com/project/how-to-repack-a-stem-seal-on-a-street-valve/

 

If it is an oring it will stretch over the threads.

 

But still waiting to see if it is leaking there or out the drain, which would be a seat issue.

[Grandpas37]

Its coming out past the washer/packing ring.  I can see if i can find an oring that may stretch over or try packing the valve. ive done that on a few faucets.  ill keep you posted with what i end up with. 

 

thanks guys!