I have working R-12 but I know my evap is packed with debris based upon the huge amount of leaves I have pulled out of side vents, cowl and behind blower motor - best place to drill on an '83 to access view of evaporator so I can shoot with coil cleaner etc. Anyone do this recently with an older truck? My truck is an '83 w250 - will most likely cut out with hole saw and use large grommet to reseal.

 

Can anyone tell me where about to cut for optimal exposure to evaporator coil ?- it is going to be packed with dirt, guaranteed!

 

Best bet is to remove it and completely disassemble it. Even if you cut a hole you wouldn't be able to get everything out. And with a truck that old all your foam seals are non existent.

 

Any idea where it is located moparite? The first gen cummins guys do this and it is quite effective. No time to pull it out, I want to vac it and shoot coil cleaner through it and let it drain, rinse, repeat.

 

Success! I was able to measure from engine bay inner fender wall to Evap ports and also located condensate drain connection which was under plenum inside cab, I was able to see just enough of the drain connection to determine where to make my cut. I made a small pilot hole and carefully just broke the surface of plastic air plenum box to determine how much room I had on the other side - Using a 3 inch hole saw and allowing about 1/4 of pilot drill by adjusting, I cut a neat hole and voila! Evap! The Cummins first gen folk use large firewall grommets to seal- need to track one down.


I was able to use hot water from a garden sprayer and coil cleaner to flush the evaporator well - lots of junk ran out and there was quite a bit of leaves and dirt which I vacuumed out first. Nice clean evaporator which I can service annually.