Could a water pump problem be associated with the air conditioning?

It is likely the compressor is making noise due to low oil level. As refrigerant leaks out it carries oil with it; when mechanics add a little refrigerant they only put that in, and not more oil. This causes a low oil condition, making the compressor noisy. If it still pumps well, take it to your shop and have the system completly drained then have them put 2-3 ounces of oil in before refilling the system with refrigerant.