I had a leak in the suction hose that I noticed when trying to charge the system. Mechanic replaced the hose and topped up the refrigerant. Okay, great, but half the time the compressor won't cycle on now. They checked the relay, drove it for several days, ran it, switched it on and off, cleaned the grounds. Say it's fine, but it cycles on and off all the time still.

Anything I can tell these guys to check? It's over 100 here and the wife/baby are not happy. Thanks guys.

 

Can you give us a little more information on the exact service the shop performed? Any leak or opening of the system really requires a drier change. Also, the expansion valve can be negatively affected by moisture in the system. What is the mileage on the vehicle and how long was the a/c not working due to the leak? Any other symptoms prior to the leak?

 

Sure thing. They stated the procedure they followed was to evacuate the refrigerant and store it, replace the suction hose, then add refrigerant back in and top up. That did nothing to ease the symptoms I had given them including an RPM surge at stop lights and cycling of the compressor. They then stated they used a relay to test the cycling switch and cleaned the electrical grounds. Not sure if they replaced any switches or sensors. None listed on the bill.

No other information given, but they had the car for 4 days and charged $450 for the hose, 1.5lbs refrigerant and 3 hours labor ($300). I'm not happy, to say the least.

Car has 109k and I only added refrigerant myself because over the last 5 years it takes slightly longer to cool down. Never stopped working on me or failed to cool. I added 1.5lbs, but the pressure gauge never went up so I stopped. Could see the leaks in the hose with the UV dye. They state I did not overcharge it, however because it was coming out. My adding the refrigerant did start the symptoms of cycling and RPM surge at stop.

 

This actually just happened to me as well. I was refilling my AC and the gauge wasn't going up and I added almost a whole bottle of EZ-Chill 18 oz coolant. After that I noticed that the AC started to cycle on and off. Did you notice your car making somewhat of a higher pitch as you rev the engine? My does. I felt like it was a possible overcharge because it wasn't making that noise before I added coolant. hmmmm.... now your experience is making me think.

 

After 2 weeks at the shop, it's fixed. They replaced the interior switch to no avail, then I suggested looking at the high/low sensor under the hood. It crumbled to dust removing it. $62 later and the AC stays on with no surging and no cycling off.

The pitch of the engine was pretty much the same, but you could hear something trying to turn over, likely compressor. Guys only charged for the part that worked. Honest mechanics, couldn't believe it.