I looked in through the cabin air intake to the a/c system's evaporator core yesterday. It's like half covered or more in gunk. I have a Siberian Husky with really fine, airborne hair and that probably constitutes a lot of it. Obviously this will impair the a/c system quite a bit!

I need to clean it, and will probably want to do that in the future on a regular basis. As best I can tell I will need to remove the engine computer and disassemble the blower housing. It doesn't seem practical to break out the cabin air intake grill and reach in there, in addition to not having much room, I'm fairly sure this will require compressed air from the back to blow off. Trying to blow this matted stuff through the fins will probably not work and it looks a bit too loose to just peel off.

Is there any better way to do it? It's my '87 E150 van.
Also the evap housing is a two-piece inside the cab. That interface leaks badly, I called up the dealer and it was discontinued 4 yrs ago. Obviously this is the time to fix it. He suggested maybe double sided foam tape which sounds useful. Anybody got an idea which may be better?

 

If its plugged badly I would just remove it to clean it. Be careful about using high pressure air so you don't bend the fins. The evaporator is quite thick and would be nearly impossible to blow out while in the housing.

 

I'm having some success. Removing that evap core would mean opening the AC system and make this job far more complicated.

I had good success washing it with a spray bottle. I also found that taking the rubber nipple off the compressed air nozzle exposed a brass nipple. I found some vinyl tubing that fit tightly on that and used it to reach in there. The diameter of the tubing is bigger than the nozzle outlet so the air was slower but has more volume, I checked and it wouldn't bend the fins. With the housing removed I could hold that little hose at 90 deg on the downside of it core and spray it out ok. Didn't get everything totally spotless but I think it's pretty good.

Now the other problem here is the seal, it leaks a lot. The outlet isn't clogged. There's this heater door assembly that is removeable and slightly uphill from the evap core and flanges out outside the housing. Now just why this leaks is somewhat of a mystery here, either capillary action or the air velocity is getting this water up the boundary and past the seal. This heater door assembly thing has a bottom to it that just lies against the bottom of the evap/heater core housing and there's no gasket.

They don't make the gasket for this thing anymore, it was discontinued 4 yrs ago. I'm not sure how to fix this thing now. I've got double-sided foam mounting tape and non-hardening Permatex gasket material. I don't think either is ideal, the mounting tape has only one chance at positioning and the Permatex could get really messy. In fact there was some Permatex in the gap already and that was the primary place it was leaking.

I don't totally understand this housing either. The way the core is mounted, there's a gasket on bottom to prevent flow around rather than through the core. But the condensate drain is only located on the downwind side of the core. Where does the condensate on the other side even end up? Perhaps this is key to my leakage problems?

 

OK after a remarkable amount of work adjusting the heater mix door cable, reassembling, disassembling, and trying again, I think I have the cable adjusted and the leaking seam at the bottom of the evap core housing sealed.

At least I had hoped. I took it out and ran the AC for awhile and when I parked there is water EVERYWHERE. Now it's apparently a large volume of water coming from the top. I think it's getting slung up there by the fan. But there shouldn't even be any water in this area!

Yes the condensate drain is clear. The water is getting past it. It is now a critical problem because the computer is in front of the evaporator and there's a lot of water getting slung around here! I found more than just a few drops of water on the computer after only 45 min or so of driving.

What can I do? This is a huge mess here!