Well, I just rebuilt my first MR-12, and I must say I'm very satisfied with the results. I could have waited to post this, since I haven't received a new 2nd stage diaphragm yet, but it should be here next week and I can post an update of some sive photos or something.
First off, I decided to rebuild this reg becuase my shop helper said it tasted bad:
After I tore it apart I was a little worried that there may be more corrosion that I had counted on. The second stage was totally green and I had a hard time removing the LP seat and nut. The exhaust diaphragm was a solid, crumbly cracker of sorts and was totally gone.
Once apart, however, I could see that the really bad stuff was only in the 2nd stage and the 1st stage looked almost new inside. Although there was a ton of silicon grease in it(??).
A soak in vinegar and a wash down and the reg looked really shiny - AND I LIKE SHINY!
I put the thing back together with no major glitches, except for one - I forgot to put the o-ring on the balance chamber. I couldn't understand the free flow at first or why the IP was sooo freakin high when the adjust nut was falling out of the reg. Oh well, live and learn.....
Here's the O-ring in place:
After re-assemlby and setting the IP, this reg seems to breath pretty good. I'll give it a dunk in the sea as soon as the new diaphragm arrives from Washington.
The kit Bryan sells is wonderfull, everything fits great and with the downloaded manual, this was as easy a rebuild as any other reg I've worked on.
I didn't paint the purge button on this either. I kind of like the satin metal look so I actually scrapped off the last few bits of black paint and then left it as is.