The "Black Death" sucks.
If you have R-12 you can flush the condenser. If you converted to 134A then the condenser should be replaced.

The reason is the R-12 condenser is a single pass while the 134 compressor is a multi-pass and usually will not flush properly.

If you keep having trouble you may want to consider an in-line filter.

Danny

__________________
1984 300SD Turbo Diesel 150,000 miles

OBK member #23

(\__/)
(='.'=) This is Bunny. Copy and paste bunny into your
(")_(") signature to help him gain world domination