2nd the vote on the flush. You can get chemicals that you spray into the system and then blow out well with air. Suggest removing the expansion valve and doing the flush from there to the compressor. Have plenty of shop air to blow all that brown oil out of the system.

Replace the expansion valve and the dryer just before your vacuum pull down. The time you need to pull down the system is really tied to the volume of air your compressor pump can move. The small loaner you get down at the auto store, I would go an hour on a opened up system.

On the oil, read up on the compressor, make sure you also add the recommened amount of oil to the dryer. A system low on oil, or with too much oil will not cool properly.

Jumper the compressor so it runs all the time when you start the car and dump one can into the system right away. After you get about half way into can 2 you should be able to feel cool air. Watch the gauges and remember that the outside air temp will affect the high side pressure reading. Meaning that if the weather is cool you will not see as high a pressure reading as on a 90+ day. You do not want to go past the 35 to 38 psi pressure on the low side if you fill in cooler weather. You will want to pull out the gauges and check it when the weather starts warming up.

And the fan makes a huge difference in stop and go traffic on those hot days.

If you have not replaced the mount bushings, order 5 polys. That way you never have to replace them again. Three for the compressor and two for the power steering pump.

Good Luck,

PT