Heater Core and Evap Coil Reccomendations

[Whitaker717]

Hi guys, sometime this summer I will be tearing into the dash and replacing the heater core and evap coil. Heat works pretty well but no A/C. I am looking for recommendations on what to get. I usually get stuff from Rock Auto or Crowne. Any recommendations would be great. Thanks

[olddude]

Tough job, take your time and label what you can. Rock Auto is a good supplier. Most stuff is made in China now days hard to fine anything made in the USA. Good luck

[AZJeff]

Buy stuff from Rock Auto, and try to stay with brands that have a reputation.

 

in looking thru RA’s selection for those years, it looks like GPD might be your best choice.   
 

too bad Four Seasons doesn’t make stuff for those older models any more

[big66440]

Just an FYI, none of the evaporators from Rock Auto will fit, I tried every single one they carry and none of them fit. I wound up going with a good used factory evaporator. 

[Whitaker717]

On 6/29/2023 at 8:31 PM, big66440 said:

Just an FYI, none of the evaporators from Rock Auto will fit, I tried every single one they carry and none of them fit. I wound up going with a good used factory evaporator. 

I definitely want to avoid used. I would think someone still makes them. 

[eaglescout526]

34 minutes ago, Whitaker717 said:

I definitely want to avoid used

I mean I’m running a used evap and it’s just fine. If you run a used evap, you just want to make sure it’s clean inside and out and it has no leaks. They’re not like the evaps of today where they’re made quickly in Mexico and end up failing 2-3 years down the road. 

[AZJeff]

55 minutes ago, eaglescout526 said:

I mean I’m running a used evap and it’s just fine. If you run a used evap, you just want to make sure it’s clean inside and out and it has no leaks. They’re not like the evaps of today where they’re made quickly in Mexico and end up failing 2-3 years down the road. 

Are the old evaporators made with copper/brass, or aluminum, like the new ones?

 

I know all the old heater cores were copper and brass, and have switched to aluminum, of course.

 

[eaglescout526]

From what I remember seeing, it’s the aluminum fins with a copper pipping core. 

[AZJeff]

1 hour ago, eaglescout526 said:

From what I remember seeing, it’s the aluminum fins with a copper pipping core. 

That's kinda interesting.

 

(Retired mech. engineer here).  Modern heat exchangers are made from aluminum due to low cost, easy fabrication, and good thermal conductivity.  (Not as good as copper, but pretty close.)   Some portions of the heat exchangers are joined using what called "dip brazing", which is a form of soldering used on aluminum structures.  Dip brazing only  works on aluminum-to-aluminum joints, so copper tubes with aluminum fins would have to rely an a close (interference) fit between the tube and the hole in the fin.   It's not optimal, but it can work.

[eaglescout526]

30 minutes ago, AZJeff said:

That's kinda interesting.

 

(Retired mech. engineer here).  Modern heat exchangers are made from aluminum due to low cost, easy fabrication, and good thermal conductivity.  (Not as good as copper, but pretty close.)   Some portions of the heat exchangers are joined using what called "dip brazing", which is a form of soldering used on aluminum structures.  Dip brazing only  works on aluminum-to-aluminum joints, so copper tubes with aluminum fins would have to rely an a close (interference) fit between the tube and the hole in the fin.   It's not optimal, but it can work.

I just went and looked. It is indeed copper tubes(or could be copper coated brass but I doubt that). I’ll have to pull down my other used core and look at it too to see what it’s made of. From what I remember, the ends are a steel structure and the fins are held on by the steel structure that supports the tubes. Kinda like a house or commercial AC unit evap. 

[Whitaker717]

6 hours ago, eaglescout526 said:

I mean I’m running a used evap and it’s just fine. If you run a used evap, you just want to make sure it’s clean inside and out and it has no leaks. They’re not like the evaps of today where they’re made quickly in Mexico and end up failing 2-3 years down the road. 

You have a picture of what an oem evap coil looks like so I can try to match it up?

[eaglescout526]

11 minutes ago, Whitaker717 said:

You have a picture of what an oem evap coil looks like so I can try to match it up?

 

[AZJeff]

4 hours ago, eaglescout526 said:

 

Those tubes are definitely some sort of copper alloy.  The plates to which they are attached may be steel (magnet check to confirm).   The only interesting part would be the fins.   I suspect they are aluminum, but without a closeup view of how the tubes pass through them, any bonding that might be involved is anyones guess.

[eaglescout526]

1 hour ago, AZJeff said:

Those tubes are definitely some sort of copper alloy.  The plates to which they are attached may be steel (magnet check to confirm).   The only interesting part would be the fins.   I suspect they are aluminum, but without a closeup view of how the tubes pass through them, any bonding that might be involved is anyones guess.

I can get some more pics. What I saw when I was taking it off the shelf was it looks like the fins have preformed aluminum tubes that slide over the copper tubes. I’ll confirm the structure the tubes are held in with a magnet as well. 

[Whitaker717]

Couple questions buddy, can you send me some links to purchase that heated core and evap coil for an 87 4.0? I just want to get the right ones. Also any luck in finding another football and servo to test on the cruise control? Appreciate it!