HVAC evaporator cleaner, which drains to use? (1 Viewer)

[CloudCity]

So after mistakenly posting in the 80-series forum and getting myself even more confused I have some quick questions for you all on doing the HVAC foaming cleaner. I have read that there is a drain tube coming from the firewall and I have located this. I understand there is a second drain tube under the vehicle somewhere but I have not located this one, most posts tend to focus on the firewall tube. Also, there is supposed to be a slit style drain tube for the core in the very back and I can't find this one either.

(EDIT: Now I'm second guessing myself if there is a lower drain in the front or if that's only on the 80-series.)

I am trying to figure out if the firewall drain is the one I would use to inject the foaming evaporator cleaner, and then will it all drain back out this line or from the bottom one? Do the two drain lines come from the same place so I only need to inject into one, or are these two different cavities? Somewhere I read that one is for the evaporator drain and the other is the AC drain, but are't those the same thing? Do I need to do the cleaner on the rear core also from that slit drain, have never seen that addressed?

Thanks all, you can tell I'm a bit confused over here.

 

[abuck99]

Only 1 drain on the 100 series: located at firewall. You won't get any benefit by trying to shoot the cleaner up into the drain- waste of time & money.

Some kits come with a shrader valve that you install in the door to the evaporator- then spray the foam through the valve. But since your LX has cabin air filters; located below and behind the glove box its easier if you remove the small access door, remove the two cabin filters and spray the evaporator directly from the access door.

 

[CloudCity]

Only 1 drain on the 100 series: located at firewall. You won't get any benefit by trying to shoot the cleaner up into the drain- waste of time & money.

Some kits come with a shrader valve that you install in the door to the evaporator- then spray the foam through the valve. But since your LX has cabin air filters; located below and behind the glove box its easier if you remove the small access door, remove the two cabin filters and spray the evaporator directly from the access door.

Thanks much, terrific advice! I'll try that method once my goodies arrive in the mail.
It's hard to tell by looking at the firewall but is the drain lower than the filters, so the cleaner will still drain through that rubber outlet line?

 

[abuck99]

It should drain as long as there isnt debris inside the evaporator compartment that would plug it up.

Best would be to vacuum out the area where the filters come out and get out what you can before foaming. You’ll have a better idea once you get in there.

Also a good time to add a drain line from the drain at the firewall down past the frame to keep the condesate dripping off the swaybar mount.

 

[CloudCity]

It should drain as long as there isnt debris inside the evaporator compartment that would plug it up.

Best would be to vacuum out the area where the filters come out and get out what you can before foaming. You’ll have a better idea once you get in there.

Also a good time to add a drain line from the drain at the firewall down past the frame to keep the condesate dripping off the swaybar mount.

Very much appreciate this, really great advice. Coincidentally I extended the line yesterday just because I noticed it was dripping in a not-ideal location. lol