2001 evap/heater core questions

mnky99

Member
Sep 3, 2025
18
1
13
Ottawa
Hello
I'm in the midst of replacing my evap core and have 3 questions (the last one is the most pressing):
1. My old evap core had some foam insulation on the top end. new one doesnt. Im going to add some. Will any generic closed-cell foam strip work? Or do i need something specific? My new heater core came with some cheap looking generic foam - I'm assuming it's safe to wrap the heater core in it?
2. Is nylog blue the best thing to lubricate the o-rings with (including the o-rings inside the heater core hoses quick connect). Or should i use PAG 46 for the ac ones and coolant for the heater ones?
3. I noticed there is a bunch of dry shredded leaves at the bottom of the evap core box.
Then I noticed that the drain at the bottom of the box goes through the firewall to nothing.
Should there be a drain hose for a 2001 v6 on the engine bay side? Something that points downwards to stop dirt and debris from going into the drain and resting at the bottom of the evap core box?
I see Ford Motorcraft part D8BZ-19858-A, but I can't get any information on it since it is discontinued - not sure what it actually looks like or whether it's even for this year/model of mustang.
I'm considering just getting some generic vinyl hose-by-the-foot at the hardware store and sticking it on, but not sure if that's a good idea.
Thanks!
 
1. Don't "wrap" the heater core in anything. The foam is meant as a spacer, not an insulator.

2. Any lubricant that doesn't eat o-rings.

3. There is no drain hose beyond the firewall.

If you decide to add a drain hose or the like, get the appropriate length of hose from an auto parts store. That way, it is oil and fuel resistant.
 
  • Like
Reactions: mnky99
Hello
I'm in the midst of replacing my evap core and have 3 questions (the last one is the most pressing):
1. My old evap core had some foam insulation on the top end. new one doesnt. Im going to add some. Will any generic closed-cell foam strip work? Or do i need something specific? My new heater core came with some cheap looking generic foam - I'm assuming it's safe to wrap the heater core in it?
2. Is nylog blue the best thing to lubricate the o-rings with (including the o-rings inside the heater core hoses quick connect). Or should i use PAG 46 for the ac ones and coolant for the heater ones?
3. I noticed there is a bunch of dry shredded leaves at the bottom of the evap core box.
Then I noticed that the drain at the bottom of the box goes through the firewall to nothing.
Should there be a drain hose for a 2001 v6 on the engine bay side? Something that points downwards to stop dirt and debris from going into the drain and resting at the bottom of the evap core box?
I see Ford Motorcraft part D8BZ-19858-A, but I can't get any information on it since it is discontinued - not sure what it actually looks like or whether it's even for this year/model of mustang.
I'm considering just getting some generic vinyl hose-by-the-foot at the hardware store and sticking it on, but not sure if that's a good idea.
Thanks!
One more question - the o-rings inside the heater core hoses quick connect, does anybody know where I can find replacements for just the o-rings?
I'd like to replace the entire quick-commect (I see Dorman makes a set) but they are cramped onto the hoses, so I'm not sure if it's possible.
I'd rather not replace the hoses as they look very difficult to disconnect on the bottom end.
 
1. Don't "wrap" the heater core in anything. The foam is meant as a spacer, not an insulator.

2. Any lubricant that doesn't eat o-rings.

3. There is no drain hose beyond the firewall.

If you decide to add a drain hose or the like, get the appropriate length of hose from an auto parts store. That way, it is oil and fuel resistant.
By "wrap" I don't mean over the fins. I mean around the edge as a padding between the core and the box, or a spacer as you said. From what you say, it appears ok to do s
Thanks
 
  • Like
Reactions: Noobz347