Hi I replaced my air con compressor a few weeks ago, had it filled and had nothing but problems - blowing hot one minute then cold the next, the car even started surging and driving really strange. Rang the company I bought the compressor from asking if they had any problems with these pumps, but obviously there wasn't any. Anyway the lad that does the regas for me sussedthe problem. Because my car has dual heating, the pump takes more gas. (750) a standard compressor takes less gas (600). So he drained the gas down and it's been fine since, except the heating in the back doesn't blow cold, and the company insist it's the correct pump