I used PB Blaster to free up the fan motor in one of those generic 7800 BTU units last week, the kind with the two-piece plastic case with vertical ribs (this one was badged 'GE')
rear bushing in motor was no problem, set it on its face and hit it with PB, then after it soaked in, with a mix of ATF and 15-40 motor oil via a squirt-can with a 6" spout
the front one took some doing, finally used a 3/4" hole-saw thru the plastic front housing directly over the motor shaft, then set it on its rear with the fan shaft pushed all the way forward
this let me see (barely) the shaft, a couple squirts of PB, wait a few minutes, a couple more squirts, then follow up with the ATF/oil mix, it free'd right up
then to the car-wash to hose the accumulated crap out, put a tap on it, a shot of R-22, then replace the $%^^&%^$#$ 88-dollar (you gotta be kidding!) combo control with a pair of toggle switches: 'OFF-ON' and fan 'Med-Hi' (no one ever uses 'low')
total cost of a working unit about 20 bucks
Hi!
>
> If you've got the time, WD-40 will do it, maybe when nothing else can. It
> isn't really a lubricant in and of itself, but I find it revitalizes tired
> old lubricants and oils quite well.
>
> Another something I really like to use is Kano Aerokroil. Not the fastest,
> but it works great on stuff that's really stuck if you give it a few days to
> penetrate in. Exhaust bolts on Buicks come to mind...
>
>
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> I do repairs on home appliances and one of the most common problems is
> seized up bearings in older window air conditioners. Very often this is
> because of the abusively hot environments in which the motors run and also
> because various things love to nest in air conditioners. The lack of
> maintenance doesn't help matters either.
>
> Last one I did had an incredibly seized motor--and it was sealed up pretty
> good by the maker. Couldn't even take it apart without destroying it. Took
> it all apart on my truck's tailgate and sat there for 30 minutes carefully
> spraying small amounts of WD-40 into the ends of the motor. After a few
> power cycles and lots of hand turning, the WD-40 apparently got in there.
> The motor started off running really rough and smoothed out nicely. >
> PB Blaster is something I can't take seriously, even if it does work great.
> The can it comes in looks silly.
>
> Still running fine three years later...
>
> William
>
>