[Farmall] O-12 chronicle, part 3

Sat Nov 15 20:58:17 PST 2008

Karl, You spent a lot of time and effort on that project, hope it all works 
out for you and I hope they pay you well for the use of your little O-12. 
John

----- Original Message ----- 
From: <olmstead at ridgenet.net>
To: "Farmall/IHC mailing list" <farmall at lists.antique-tractor.com>
Sent: Saturday, November 15, 2008 7:45 PM
Subject: [Farmall] O-12 chronicle, part 3

>A year or two ago I posted a couple of messages about a running O-12 that
> I picked up at the November Tulare, CA swapmeet.  At that time I did quite
> a bit of work on it.  Rebuilt the fan, replaced the magneto, flushed and
> drained the transmission, dropped the engine oil pan and cleaned it up,
> fixed the damaged oil filter mount, changed the oil, dropped and lubed the
> front axle and steering parts.  After all that, the tractor still had
> serious problems.  The transmission flush reavealed that the countershaft
> seals behind the brake drums were shot; both brake covers filled up with
> lube.  The radiator kept leaking faster and faster as I exercised the
> tractor.
>
> I removed the seat, fenders and transmission cover, but then priorities
> shifted and I eventually hauled the O-12 off to my storage shed.
>
> About a month ago, a buddy of mine from northern California emailed me and
> said that some movie folks were looking for a 1930 to 1940 vintage tractor
> to use in a documentary which was going to be shot at Inyokern airport,
> which is only about four miles from where I live.  I emailed the movie
> people and asked what they had in mind.  I offered to help them find a
> tractor, and invited them to take a look at what I had.  As it turns out,
> the documentary is about an amazing German WWII aircraft, a flying wing,
> and they really wanted to find a European tractor to pull the mockup that
> they had built out of a hanger.  I was able to locate a 1948 Ford airport
> tug, but they weren't very interested.  I sent them pictures of the 1934
> F-20 that I bought from Bob Currie, but I warned them that tricycle
> tractors were never very popular in Europe.  Anyway, they dropped by and
> really liked my '36 O-12.
>
> They like it because it is small and low, like an airport tug should be.
> And it is extremely nondescript.  Lots of 'patina' and no paint or decals.
> It'll be nearly invisible compared to their airplane.  Especially since
> they plan to shoot at night sometime in December.  They can arrange the
> lighting to focus attention on their subject.
>
> That meant that I had to fix up the tractor.  It started right up, despite
> at least a year of inattention.  But when I filled the radiator, it
> sprayed water like a sprinkler.  No hope there.  It was a significant leak
> when I put it in the shed; now it was a geyser.  And I found a half inch
> diameter rust hole in the bottom tank.
>
> I came up with a plan and waded in.  Removed the tractor's wheels and
> tires, which are extremely heavy.  That cleared the way for brake drum
> removal and cleanup of the grease-soaked shoes.  I had countershaft seals
> on hand, but the -12 series have a goofy countershaft arrangement.
> McCormick-Deering splined the countershafts for the brake drums, but the
> splines were too long, no way the seal would work, so they slipped a
> bushing over the splines, and that is what the seal slides against.  It
> kinda works, but there is a leakage path between the countershaft and the
> bushing.  It's just a loose metal to metal fit.  I squirted some RTV
> between the shaft and bushing, hoping that it will stop leakage.  I'll
> eventually find out whether or not that worked; I'll need to dismantle the
> brakes again before long; the old linings need replacement, and the new
> ones didn't come in until yesterday.
>
> Re-installed the old brake shoes, drums and covers, and put the wheels
> back on.  Cleaned up the fender mounting holes on the axles and installed
> the fenders.  Cleaned up the transmission cover mating surface and the
> transaxle, dumped in some GL-1, and bolted the cover back into place.
> Installed the side hinged seat bracket and scrounged up a better seat from
> my parts tractors.  That pretty much completed work on the rear of the
> tractor.
>
> Pulled the radiator and set it aside.  Hauled another O-12 down from
> storage and removed its' radiator.  It had better looking tanks and core.
> Dismantled that radiator and began cleanup.  I hate old tractor radiators.
> Since nobody used antifreeze and the bottom tanks are always wet, they
> rust like crazy.  I usually find the bottom tanks FULL of rust.  Put on my
> ear protection, face shield, dust mask, apron and gloves, and cleaned up
> the tanks with a needle scaler.  Then sandblasted the tank flanges and
> took a pass with my milling machine to try and flatten out the flanges.
> That revealed considerable warpage and pitting, so I used JB Weld and PC-7
> to build up the flange surfaces until the mill made a nice smooth surface.
> Did basically the same to the various inlet and outlet fittings, but
> cleaned up the mating surfaces using a disc grinder instead of the mill.
>
> Began radiator reassembly yesterday and completed it today.  Didn't get
> the new gaskets in time, so I used RTV sealant in place of gaskets.  Will
> check for water tightness tomorrow.  The core is an unknown; I cleaned it
> up several years ago, but it has never been tested.  I hope it doesn't
> leak!
>
> I think I fixed the massive oil leak from the filter cover.  I was getting
> very high oil pressure readings, so I clipped a couple of turns from the
> regulator spring.  Pressure's still high, but maybe not off scale any
> more.  Won't know for sure until I can fill the radiator and run the
> engine longer.  I suppose it is possible that I have a blockage downstream
> from the oil pump, but I haven't heard any knocking.  May tap into the
> main oil galley and try and learn more.
>
> I still have about a month before the tractor is needed for the
> documentary, so I should have it ready in time.  No real surprises; I knew
> that the tractor needed a lot of work to make it usable; that's why it got
> stored.  I wasn't wrong.  And I wasn't motivated enough to take on the
> project until somebody else needed the tractor.
>
> What made this whole process unusual is that I had to keep 'patina
> preservation' in mind.  No sandblasting of visible surfaces, no priming
> and painting, etc.  In fact, in the places where I was forced to use new
> fasteners, I'll probably have to spray paint the new stuff with red oxide
> primer.
>
> If this one works out as well as I hope, it could become one of my
> favorite tractors.  For some reason, I like antique tractors that are
> still in their original condition best.  But they need to run well and not
> leak too badly.  If nothing else, they are much easier to work on than a
> nicely painted tractor; no worrry about damaging the paint.
>
> I'll let you know how it works out.  I'll probably ask an unemployed
> friend of mine drive the tractor for the documentary.  Don't see myself
> working outside until midnight some December night, and he can use the
> money.  I don't need to be in a movie.  Ever.
>
> -Karl
>
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>

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