NA Miata a/c resurrection

With my 90 on the road & July around the corner, getting the a/c working is probably a good idea. I have access to a vacuum pump, gauges, and someone who knows how to use them, so that’s covered. 

My concern is the unknown: the system has been open to the elements for about a year, but I have no idea if it was working at that time or already broken. Is there any testing I can/should do, or any parts I should preemptively replace, before we draw it down & add Freon/dye?

I was advised to give it some compressed air to check for leaks and to make sure that the compressor clutch enagages.

I believe conventional wisdom says you should replace your receiver/dryer any time the system has been exposed to air. In fixing the A/C in my RX7 this spring I also replaced every easy-to-reach o-ring and the two schrader valves. After testing with dye, it turned out my big leak was from the high side valve not sealing completely.

Armitage said:

I believe conventional wisdom says you should replace your receiver/dryer any time the system has been exposed to air. In fixing the A/C in my RX7 this spring I also replaced every easy-to-reach o-ring and the two schrader valves. After testing with dye, it turned out my big leak was from the high side valve not sealing completely.

This. Id also do a can of the flush through all the components while it's apart. If you get metal, compressor is bad. Do a new orifice tube oe expansion valve while youre in there

Thanks everyone, time to order more parts!

Dusterbd13 said:

Armitage said:

I believe conventional wisdom says you should replace your receiver/dryer any time the system has been exposed to air. In fixing the A/C in my RX7 this spring I also replaced every easy-to-reach o-ring and the two schrader valves. After testing with dye, it turned out my big leak was from the high side valve not sealing completely.

This. Id also do a can of the flush through all the components while it's apart. If you get metal, compressor is bad. Do a new orifice tube oe expansion valve while youre in there

As a just in case, does the parts car have a condensor?

In reply to Dirtydog :

I’m not very well versed in a/c terminology, the condenser is the radiator-type thing? I have a couple spares of those(with what I think is the accumulator attached). 

Condenser is in front of the radiator 

Roger that.    IFO radiator.

I just danced the Tango with the AC in my Volvo.  You learn pretty quick what you can and can't do, unless you got access to the right tools.