1991 Miata AC system
I own a 1991 Miata that I bought used. The previous owner converted the AC from R12 to 134a. He only replaced the low side inlet with a long adaptor. In the past I was able to use cans to recharge the system when needed using that adaptor. This spring, I was not able to charge it, so I took it to my local shop. They replaced only the low side adaptor and charged the system. Upon checking their work I found that the put a HIGH SIDE adaptor on the LOW SIDE port! and again did not touch the actual high side. Since I do not know how commercial AC charging systems work, I can only assume that they charged the car through the my low side line with their high pressure hose. Will this have caused any damage to my car's AC?

