Replacing A/C Evaporator - Tips

[Flyer1]

As an FYI for folks here, if you find you need to replace your evaporator, I'll pass along a couple lessons learned. This post got pretty long, but it was a big job.

What happened in my case was the 134a was leaking down in about 4 days and I'd lose almost all the cooling from the A/C. I couldn't find a leak under the hood and the halogen leak detector appeared to ping on the vents. I thought the evaporator was leaking so I concluded I had no choice but to R&R it. Dealer wanted ~$1400 in labor so opted to do it myself. (and I like working on cars and have this thing about if you want it done right, do it yourself!) About 25+ hours working on the X plus many hours chasing down parts and its back together and charged up with 134a. Never did find a leak so may still have the problem. (compressor seal perhaps...) Haven't driven the X enough since the repair to find out.

Lessons learned:
1) Be careful prying out the leather cover around the emergency brake handle. There are a lot of plastic clips, more than you would expect.
2) If your removing the trim at the base of the instrument cluster, there are three screws attaching it to the dash. One is above the steering column and hard to see (this trim does not have to come out to take out the dash or the cluster)
3) The TIS explains how to get the dash out, but goes no further. Getting the metal tubing (dash support) out isn't difficult though. 10 bolts in all. 4 on the steering column, two at the base of the center console, one near each door hinge, one above the steering column and one smaller one near the headlight control unit. (sorry but I didn't get a good pic of this part of the work)
4) Don't try to dissassemble the evap housing in the car. It is attached to the firewall by 4 studs with nuts to hold it in place. After disconnecting the heater hoses (easy to do - just pull up the metal clips and work the connection apart - don't twist because the connection is slotted - just pull) the evaporator housing pulls out easily from the firewall.
5) once the evap housing is out of the car, take out the blower motor and the side of the housing that faces the firewall to get to the evaporator. You will not have to remove the heater core and the lines going to it if you dissassemble the plastic housing this way.
6) once the front of the evaporator housing is off, remove the small metal clips, flip the thing upside down and work the bottom off allowing you to get to the evap.
7) Be careful with non-OEM parts. I tried an aftermarket evaporator I got off e-Bay and the connection to the expansion valve was at the wrong angle. It placed the expansion valve too low and there was no way to connect up to the "double pipe" that connects the expansion valve to the lines in the engine compartment. You would have to bend the lines on the evaporator. Since it was so much work getting to the evaporator I opted not to chance doing damage to the evaporator. I bought one from BMW for twice the price - but it fits perfectly and comes with the foam that helps seal the evaporator to the inside of the plastic housing.
8) The bolts attaching the expansion valve use a small hex (3mm I think) and are soft metal. I stripped one because it was frozen in place. Applying some penetrant before attempting to remove them may help. (you might be able to do this if your only replacnig the expansion valve from the engine bay side and do not have the entire assy out of the car) Drilling the bolt and using an EZ-Out took it out without any problems.
9) I mistakenly removed the side ducting and servo motors that drive the flapper valves for controling the direction of air flow off of the evaporator housing. I was trying to get to the evaporator with the housing in the car. It was a bit of a jigsaw puzzle to put it back together. If you find you have to take those parts off the evaporator housing, it only goes together one way so you shouldn't get any of the flapper valves out of sequence.

If your doing a job like this for the first time, take a bunch of digital pictures before you tear it apart. They are a good reference for when you need to put it all back together. (EG how wires are routed)

You WILL break a plastic clip here and there. Its almost inevitable. Especially some of the clips that attach wire bundles. In my case, the ones that broke I was able to use plastic wire ties instead.

After doing all this a/c work, baking the headlights to install angel eyes doesn't sound that bad!

I tried to imbed the images in the post but "Preview Post" is only showing the URL's.

In work:
http://www.x3world.com/attachment.ph...1&d=1191532643

The TIS will explain how to get this far. Note the metal dash support:
http://www.x3world.com/attachment.ph...1&d=1191532780

Everything removed:
http://www.x3world.com/attachment.ph...1&d=1191532780

I hope you never have to go through this, but if you do, I hope the above info helps!

[Flyer1]

My bad..no metal dash support in the second pic. One partial view of it here: