The short answer is...yes and no. An experienced tech can usually get it close but the BEST thing to do is recover and recharge by weight. That way, one can rule out the refrigerant charge as a problem. The most common problem is refrigerant charge. If you had a cycling clutch system that used an ac...

Can you record it with your phone?

Is it leaking or low on refrigerant now? You want the system to be leak proof before adding a new drier. If it does not leak now, recover the charge and change the drier. Vacuum the system down and add your refrigerant.

Can you state what parts were replaced? Back then, Fords had bad cycling switches, compressors, and I think they had blend door problems. The noise you hear may be the system equalizing. If possible, check and see if the center hub of the compressor is turning when it is blowing hot air.

1987? You should consider all new hoses.

Are you planning to use 2 evaporators? You will then need a separate metering device like they do for rear evaporators in a vehicle. It might help if you describe your vehicle as in make, model, and year. Also, what compressor are you using? do you plan to use a different condenser? A compressor can...

The valve core is actually the secondary seal. The cap is the primary seal. Are your caps in place? do they have a rubber seal in them?

When it starts to blow hot, is the front of the compressor turning? Fords had a history of bad cycling switches.

At what RPM are you getting 42 low and 225 high? I see you stated you charged by weight but R134 needs less refrigerant than R12. Could you possibly be slightly over charged? Did I ever tell you I do not like to convert? This is coming from someone with a butt load of R12. GRINS

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