As long as there was no leak in the evaporator, there should be no need to do these both at the same time.

The main thing, since the compressor is being replaced due to seizure, is to THOROUGHLY FLUSH the system. You will need to flush, Flush and FLUSH! Any particulate left in the system will find its way back to the compressor and destroy it.

Also, you can go to an auto a/c supplier and get a suction side filter, which is sometimes only a screen. This goes in the line at the suction side of the compressor. DO NOT RELY ON THE FILTER DRIER FOR THIS PURPOSE. There is lots of volume after the filter drier from which junk could come and destroy your new compressor.

So, to summarize; flush the system thoroughly, replace the filter drier, see that the correct amount of oil is in the compressor, use a suction side filter and evacuate thoroughly before charging.

Good luck,

PS: Did I remember to say something about how important it is to thoroughly flush the system after compressor seizure? LB