For many years my 91 has had a very slow AC leak....didn't know where and didn't care. Just added refrigerant once a year.

This year I discovered a bad condenser leak, which I assume was separate from the other leak (although no way to be certain). So my indie replaced the condenser and I had ice cold AC once again.

After a few months, AC seemed noticeably weaker, so I assumed original minor leak was rearing its ugly head. When I looked at the low side port, it was covered with dye and bubbling. So there's the source of my leak, I thought. BUT when I added refrigerant and checked the valve again, it wasn't leaking at all. Somehow by opening and closing the valve there was a tight seal once again.

Can old Schrader valves be temperamental that way? Where, if they leak, just opening and closing again seals it? Or does it sound like I need to replace that valve at some point?

With summer almost over in New England, I have little motivation to throw more money at the AC in this car. But, with all the money I've already spent, I want to be leak free before next summer.

Thanks.

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14 E250 Bluetec 4Matic "Sinclair", Palladium Silver on Black, 158k miles
06 E320 CDI "Rutherford", Black on Tan, 177k mi, Stage 1 tune, tuned TCU
91 300D "Otis", Smoke Silver on Tan, 144k mi, wastegate conversion, ALDA delete

19 Honda CR-V EX 72k mi
Fourteen other MB's owned and sold
1961 Very Tolerant Wife