Cadillac & LaSalle Club Discussion Forum

Cadillac & LaSalle Club Forums => Technical / Authenticity => Topic started by: 39LaSalleDriver on December 02, 2021, 12:45:24 AM

Title: 1939 LaSalle - Brass Plugs for Block Drain
Post by: 39LaSalleDriver on December 02, 2021, 12:45:24 AM
This week I decided it was time to do a flush/drain/fill of my coolant system for the winter. Every time I go to do something like this, I always forget that some previous owner broke one of the ears off one of the brass plugs that fit into the block. It still works fine, so this isn't anything critical, but it does irritate me and makes removal a bit more difficult. Does anyone know where I could find a new one, or perhaps even what it could be replaced with? Ideally, I'd like to keep the originality rather than trying to replace the whole fitting.
Title: Re: 1939 LaSalle - Brass Plugs for Block Drain
Post by: fishnjim on December 02, 2021, 08:55:08 AM
Perhaps a picture may help here and post in wanted parts.

I'm not a pre-waree, so not completely sure, but I don't think they changed the basic radiator drain plug at all, there's internal and external seat types, until they went to plastics.   It might vary a little over the decades, but the brass drain "cock" type plug has been in use forever.   They are readily available at any parts store or internet.   The handles are crimped and notorious for spinning, and not turning if tightened too tight.   A touch of solder helps.
Anything metal can be fixed to some extent, so possible maybe repaired also.

If it's NPT thread, a brass pipe plug will do, but messy when it comes time to take out.   If there's "room", you can also install a nipple and valve or petcock.   I did that on my air compressor because it's a mess to drain from the supplied plug.   This way you can slip a hose on it and direct to container
Title: Re: 1939 LaSalle - Brass Plugs for Block Drain
Post by: 39LaSalleDriver on December 02, 2021, 10:46:29 AM
This isn't your typical petcock arrangement. Here is a photo I borrowed from Scott Mrdeza which shows it. The left piece which fits in the block is missing the threads which fit into the block. His sheared off when he tried to remove it. I don't wish for that to happen, plus I'd like to keep it as original as possible thus my inquiry.

As it stands, I may just have to live with it "as is" but figured it was worth a shot to see what others might know.
Title: Re: 1939 LaSalle - Brass Plugs for Block Drain
Post by: LaSalle5019 on December 03, 2021, 08:48:21 PM
Hey Jon,
You can have my old one. Once I sheared off the base I had to find a replacement and found a vintage new assembly that is just a bit different than the original. I'm like the most retentive person for originality but it was close enough that it doesn't even bother me  :D  Send me a PM with an address and I'll drop it in the mail.
Scott
Title: Re: 1939 LaSalle - Brass Plugs for Block Drain
Post by: fishnjim on December 04, 2021, 09:23:38 AM
Always helps to lay a rule down next to parts when taking pictures.   So you can tell what size it is.   
Appears to me, the male threads going into the block are the ones that are failing/sheared off.
If this guy's offer isn't what you want and you can't locate a good OEM, take it to a machine shop and have them cut you a new base out of brass.   Can reuse the
"stopper".   You can have several made and sell them to offset your costs.

Not in my wheel house of parts info.   If I get some time, I'll search what I got and see if I can come with more info, part #, man., etc. as this common problem will persist.

I suggest you use teflon tape or pipe thread sealant when you re-install.   The dissimilar metals are causing an issue over the long haul.   Thin brass isn't that strong so overtightening is an issue here.   NP threads are tapered, jam as the tighten.   
I don't think they had any idea people would still be using LaSalle's when this was made.
If it's regular 1/4" or 3/8" NPT, I think a regular radiator drain valve would work, but not what you're after.   Or the other solutions I proposed.  I'll even say the dreaded word, plastic coolant drain valve.   
ps: Closest thing out there would be for marine engines, Sierra Marine makes similar block drain valves, which would function and look close but aren't exact.  Maybe able to buy and use your plug in it, but a wild guess.
Title: Re: 1939 LaSalle - Brass Plugs for Block Drain
Post by: 39LaSalleDriver on December 04, 2021, 01:08:09 PM

Quote from: LaSalle5019 on December 03, 2021, 08:48:21 PM
Hey Jon,
You can have my old one. Once I sheared off the base I had to find a replacement and found a vintage new assembly that is just a bit different than the original. I'm like the most retentive person for originality but it was close enough that it doesn't even bother me  :D  Send me a PM with an address and I'll drop it in the mail.
Scott


Thanks a bunch Scott! Will send PM. I'm more than a bit AR about such things myself, but sometimes ya gotta do what ya gotta do.