Heater Core Removal Problems

Hello -

I'm neck deep in removing the heater core on my 04... having issues pulling the assembly out.
I'm 99% sure I've got everything disconnected - dash is out, wiring disconnected, heater lines/AC, 4 firewall nuts.

when trying to pull the assembly out, the driver's side is free, but the passenger side is hanging up - there is a little play, but it won't come out. It feels like the mounting bolt threads by the AC lines are hung up on the firewall - I get that noise of threads rubbing but it hangs up pretty quickly and won't budge.

Should that assembly come right out or does it have to be massaged at just the right angle? I'm afraid of pulling too hard and breaking something. The evap lines seem to be free - I can push on them from the engine side and there is a little movement.

http://forums.tdiclub.com/showthread.php?p=1967465
http://forums.tdiclub.com/showthread.php?t=232824

Prairie Chicken,

Did you remove the expansion valve? I've done two heater cores and am pretty sure the expansion valve needs to come off the evaporator ends to get the heater box out. There is a bracket behind the expansion valve that is similar to the one on the front of the expansion valve that holds the lines in place.

Eric

Shenandoah said:

Prairie Chicken,

Did you remove the expansion valve? I've done two heater cores and am pretty sure the expansion valve needs to come off the evaporator ends to get the heater box out. There is a bracket behind the expansion valve that is similar to the one on the front of the expansion valve that holds the lines in place.

Eric

Click to expand...

yep - expansion valve and the bracket. Only the evap lines are coming thru the firewall (and the mounting bolts).

once you got everything disconnected did the assembly easily separate from the firewall?

I know how these jobs go... I'm sure I got everything disconnected but I'm stuck here so something's gotta be wrong. I read the How-To's and Bentley about 5 times and 100 more times since getting stuck, just not finding the problem (besides the idiot mechanic) lol

If you pull hard enough, you will figure out what was still held on.

Prairie Chicken,

Isn't there a nut underneath the expansion valve? Do you have the cabin filter removed?

Eric

For the record, the expansion valve doesn't even need to be removed to pull out the heater box. The whole thing fits through the opening in the firewall rather easily.

Perhaps the wiring harness is still clipped onto the box?

Baaaaaaah!

Cabin filter yes. Housing underneath it no. Yanked that out and voila. Jr came back for Christmas break today... it helped to have him in the car moving it around so I could see from the other side.

That seal on the bottom of the housing was really stuck on there... nothing like a dozen TX summers to cook the rubber on.

Thanks for the tips.

Man do I feel for you! Did one of these in the wife's car a couple of summers ago: 2000, single piece HVAC

Seem to recall that there's some plate at the firewall around the expansion plate. I know that when I reinstalled I taped that plate to hold in in place. Might be that the plate is dropping down and catching up on the hole through the firewall.

Yes there is a plate there... but it wasn't in the way - it dropped into the coolant drip pan when I was pulling it out and is still there. lol. That cabin filter housing was the elephant in the room.

Once I got it loose I came inside to watch the rest of the Bronco game. I'll get the core swapped out tonight and should get it all back together without issue, I have pics and a trail of parts laid out in the order I removed them.

thanks again!

Prairie Chicken,

Excellent. Replacing a heater core is an adventure, to say the least. Re-assembly can be a challenge remembering where everything went/goes. When I did mine I took a lot of pictures for reference.

Eric

Shenandoah said:

Prairie Chicken,

Excellent. Replacing a heater core is an adventure, to say the least. Re-assembly can be a challenge remembering where everything went/goes. When I did mine I took a lot of pictures for reference.

Eric

Click to expand...

My wife looked at her car as I had it all apart and asked me if I knew how to put it all back together. As stated in some DIY, if one is bothered by seeing a picture of what things look like all apart then maybe they ought not undertake this job!

Shenandoah said:

Prairie Chicken,

Excellent. Replacing a heater core is an adventure, to say the least. Re-assembly can be a challenge remembering where everything went/goes. When I did mine I took a lot of pictures for reference.

Eric

Click to expand...

Yeah, and I have round 2 with my 99.5 because the OEM VW heater core failed 3 years later. At least it has the split box.

3 years??? Ouch... hope the next one lasts longer.

turbocharged798 said:

Yeah, and I have round 2 with my 99.5 because the OEM VW heater core failed 3 years later. At least it has the split box.

Click to expand...

Split box on a 99.5? How did VW go about assigning the different types? Wife's car's was a single. If there's a (relatively easy) way to change to a split I'd seriously consider doing it in the course of any future HC replacement. I've got THREE 2000 Golfs and I'm thinking that that means ALL have the single HVAC box.

so - after several therapy sessions I feel I can talk about this now...

I ended up having to replace the evaporator also as it had a small leak... no big deal. For the blend/mode doors I went with the foil tape on both sides and didn't worry about the leaks from the sides. The air flow is much better but you can feel a little flow coming out the front when defrost is on. Next time I might try some foam or felt, or possibly something on the plastic where the doors meet but it is such an improvement over a door with no foam I might stick with the foil tape and call it a day.

All together it isn't that challenging technically, but it is a ton of little jobs that add up to one massive job. I will say it is probably the worst job I can remember doing over the 30 years I've been tinkering. I certainly don't want to have to go thru this again but with the 4 TDI's I currently own (and more buys/sells/upgrades likely coming) I'm sure I'll run into this down the road and will be able to execute it much more efficiently. That being said, this is one job where paying someone to do it for me is very very temping.

Next time I will try disconnecting the seats but leave in place as much as possible. A lot of the disassembly can be done from the chair instead of being on knees or sitting at funny angles. Those with bad backs will know where I'm coming from.

Best advice I can give is what Eric and the others have said time and time again - you cannot take enough pics and notes of the tear down.... what screws go where, the exact order of what you took off and when, where the wires run exactly... ect. It is a very doable job but requires much patience and again document everything you do.

Happy Holidays to all... Kevin