A/C sysmptoms

[dz09x]

Finally going around to fixing my AC system. Went to pepboys and got a can of the r134a with UV dye. Put it in the system and came into an odd problem. The clutch engaged after a a few seconds of charging. The system pressure was basically dancing between 20 and 30 psi, and I mean the needle was moving around and fluctuating. I checked the system using a black light for any signs of the dye and it was nowhere to be found. The needle at times would just be shaking in one spot, usually around the 25 psi mark. Lastly, as I was under the car and my girlfriend was charging the system, I heard a loud knocking sound coming from underneath. Once i Turned off the AC system, the knocking stopped. Something tells that there is a problem with the compressor. Just want some input from other members if they ever experienced anything like this and what a suitable repair would be.

As always. Thanks for any and all help.

[flatlander745]

Same thing on mine but compressor was leaking around outer casing, not knocking. Find a good used compressor and put in a new orifice tube and dryer. Make sure you get AC #15-33897 o-ring kit for the compressor lines...it will leak if you don't replace them!
http://www.amazon.com/ACDelco-15-33897- ... B001S88P4G
Compressor is pretty easy swap, jack the right front up, pull the wheel and inner splash guard and the compressor will slide out from that opening. Make sure you have 2-3 oz of PAG 100 oil in the compressor before install. Take it to the dealer or Pep Boy for a recharge and Vac check, around $120.00.