Dazed and Confused
Join Date: May 2012
Location: Upstate New York
Re: 1984 F250 6.9 A/C compressor
Brake cleaner is an excellent choice actually, providing there's no software that will break down due to exposure. R-11 or R-113 would be better, but the EPA and the Federal Government kinda frown upon it. Just make sure you evacuate it well and as you pointed out, install a new filter.
I'll have to worn you, though, there is a risk of corrosion products left behind due to air and moisture. Foil won't keep that out. My truck's AC has been open since 08 and for that reason, I've abandoned it. Cut the hoses off at the fire wall and eventually I'll dig the evaporator out of the dash.
Ever notice that there's so many high performance parts available for GM products?
Did you ever think that maybe they NEED them?