When replacing an A/C compressor in a vehicle, it’s important to know why the compressor failed. If the compressor was leaking or failed electrically, it may only require new refrigerant and compressor oil along with the compressor. A compressor that failed mechanically is entirely different, however, as metal debris from within the failed unit may have contaminated the system. In this case, a filter and receiver dryer are necessary at a minimum, and other refrigeration components such as a condenser or hoses may be necessary if they have been plugged up with debris.