in response to a message on the NetVette # 1460
.? 74 can ya blow out debris in the evaporator without removing?

If your model has significant debris inside the evaporator case, you can rest assured that this same matter has permeated the spaces between the fins. Often organic matter (leaves, acorns, seeds, insects, etc) lodges there, and decays. I personally do not think enough debris could be removed via the method you describe. If conditions are such, it can only be thoroughly cleaned by splitting the evaporator case. Perhaps if only the driver’s side of the case is removed, and the core is unbolted from that half of the case - you may be able to dislodge the debris with a strong stream of water and scoop it out via the blower motor hole. However to effectively clean and prevent a re-occurrence, I would suggest a complete removal.

Note that this rotting debris lodged in the fins will also accelerate the “rusting” of the evaporator. These Aluminum cores are expensive as are the Freon charges. Evidence of white crumbling powder will confirm that “rusting” is occurring. Since Delco is now an entirely separate business entity from GM called Delphi, I would expect an even faster discontinuation of these obsolete parts from their product line as they no longer must supply them to the General.

Incidentally, if you consider partial or complete removal of any or part of this system – I have reproduced every seal GM ever used and even added some to assist the 68-82 AC system. You can read further about them and other Climate Control Solutions