In March ‘09 a recommended local shop replaced my ‘98 Audi A4 A/C compressor (it had not failed, yet, only was making very loud noise when on), now 5 months later the system only blows warm air. Shop says they need to replace the low pressure line since “something” over time rubbed a hold in it allowing all the liquid to leak out. Shop says vibrations from driving over potholed roads could have caused this. I’m thinking they did not do something right when they replaced the compressor. Is it possible their explanation is correct? Should I be taking my car somewhere else for repair?

They also said while they're in there, I should also replace the high pressure line though it is not presently damaged. Sounds like a good plan or not? Total estimate is $900 to replace both low and high pressure lines including refrigerant/other parts/supplies. Should I be concerned that the compressor or other parts in the A/C system might have been damaged?

Thanks!