Hey, I hope someone has experience enough to solve my conundrum. I’m a skilled (40plus years) DIY mechanic. My son’s 2008 VW Rabbit’s A/C was cooling at about 60% capacity. No problem, just needs some refrigerant, (Done this 15 plus time to other cars over the years) so we added 510g of R-134a to the low side port, engine on, A/C on max. The entire time the hose gauge stayed in the green area, never red. The output improved, definitely cooler, but still not ice cold. Because the hose gauge never got into the blue range we presumed it still needed some more refrigerant so off to the store we went. About 10 miles later, the A/C quits blowing cold, fuse is ok. The local VW dealer finds bad compressor and about $1000 later he has cold A/C again. So did anything dear old dad do cause the compressor to fail or was it just on its way out. (If its somehow my fault, I want to help him out with the repair cost.) The VW compressors are notoriously unreliable from what I read on the forums. Thanks for reading, and greatly appreciate any helpful insight.
I dunno. 10 miles seems short. I suppose it could have needed oil with the recharge but maybe the compressor was shot anyway and never needed a recharge. Glad I’m beyond that phase but I would have been paying the whole bill. Maybe the shop can tell why the compressor failed.
I am not sure I would trust the hose gauge. A set of gauges that reads both high side and low side would be my choice. An overcharge on a system can reduce the cooling just as an undercharge can. I think it is possible the system was overcharged, but an AC expert may know more about this.
In the fall, I discovered my 2002 Sienna was low on Freon. Instead of going to an automechanic, I took it to a place which services truck compressors. It took them seconds with a black light flashlight to spot the leak at the compressor seals.
Instead of paying for a new compressor, around $1000, having the compressor seals replaced was well under $200.
Their one year guarantee was very explicitly only for the compressor seals, which makes sense because that is all they worked on. They had my seals on the shelf.
I do not know if they can do other compressor repairs besides seals. It won’t cost you much to call and find out when you have a compressor problem, though.
Note the above compressor repair was during my annual one month visit back to the States.
The overcharge may have blown out a weak compressor. But, it sounds like the compressor was on the way out anyways. Without a high side reading, however, this is all just a wild guess. But, if the first can didn’t get it cold enough, low refrigerant was not your problem.
The refrigerant capacity is only 525g, unless the system was empty you likely over charged it. If the dealer found the compressor was leaking that may have been the original problem and not caused by over charging the system.
If the relief valve popped and would not seal this may be why the compressor was replaced, some manufactures don’t offer the relief valve separately.
Best to ask what the problem is when given an estimate of repairs. Perhaps the cause of failure is listed on the invoice.
You didn’t damage the compressor.
The AC system has a high pressure switch that cuts power to the compressor if the pressure gets too high on the high side of the system.