I got a 2003 Honda CR-V with an ac compressor that’s been leaking for the past 3 years. I live in Toronto and figured I don’t really need ac other than for about a few days for 2-3 months. So I have been refilling it with refrigerant every summer and driving around and the ac blows nice and cold still. I would keep doing this for as long as I could but I wanted to know if it is worth replacing the whole system at this point or just driving around till the entire ac system gives up and replacing it all then since I would probably have to replace the whole system now anyways.
I've been doing this for years with my '99 Jeep Cherokee. It has a leaky evaporator and to replace that the entire dashboard has to come out. Easier to top the AC up once or twice a season. (In my case it does not get down to zero pressure so no need to pull vacuum. As long as there is pressure in the system air and moisture will not get in.)
The only way to know you have the correct amount of refrigerant is to evacuate the system and put in the correct amount by weight. That's by the book. However, if you are careful what you can frequently get away with is topping up the system while watching system pressures and outlet temperature. When you get to a good point you stop adding refrigerant. The older the AC system the more likely you'll be successful this way. (The newer compressors are much more sensitive to refrigerant load than the old ones. Also with variable displacement you really can't judge charge level by pressures since the compressor will maintain pressure over a fairly wide range.)
This is not a good long term approach, however. If you plan to keep the vehicle as long as possible and have functioning AC it would be best to check for leaks using either dye or an electronic detector and fix them. With dye you can't check directly for evaporator leaks on most vehicles since that part is not easily accessible, but you can check indirectly by looking for dye coming out of the condensation drain.
Always wear eye protection when working on air conditioning and don't use refrigerant that has sealer in it.
Ideally, you want to find the leak and repair whatever it is that's leaking. UV leak dye and chasing it with refrigerant will reveal the leak if it's anywhere but inside the dashboard. They all slowly leak, but not within a year.
Recharging and running will eventually blow the system in one of two ways. If you're not evacuating the system and putting the proper weight in right away, you have moisture in there constantly, which will corrode the internals and eventually cause the compressor to lock up.
Every time you refill the refrigerant and it leaks out, you're pushing the PAG oil that lubricates the compressor out of the system, through the holes. It dissolves in the refrigerant, and comes out via the leak. Running dry will cause clunking and eventually destroy the compressor.
Do a leak dye test. Your condenser probably has holes in it. It's the most exposed part of the system.
