Larry:

The evaporator always leaks at the crimp connections on the driver's side. Check that drain line for the dye if you want to verify no leak.

Mine was bad enough my GowMac leak detector would "see" freon at the dash vents for a minute or two with the fan on low after the car had been sitting a while. Green dye all over that side of the box.

Cap'n:

Goo on the windshield is usually coolant, not compressor oil.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!