AC compressor noise

[Brian Link]

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My compressor used to make a howling noise.  I fixed it by recharging my
system and adding 1.5 oz of oil when I replaced the high pressure line.
No more noise.

I replaced a bad horn, and in the process moved the horn bracket which
wore a hole in the high pressure AC line, letting all my R-12$$ out into
the ozone.   I replaced the hose with a scavenged replacement ($25),
pulled a good vacuum on the system, and refilled with "enviro-freeze".
BTW the pressure on the low side with the compressor engaged is only 32
psi when system is fully charged.   Instead of 43 psi with r-12.  Oh
well compressor is quiet, ac blows very cold.

Brian