Expansion Valve REplacement

[numberkruncher]

94 Legacy
I'm pretty sure I have a malfuncioning expansion valve.(Compressor engages, High pressure goes to about 360psi, low drops to <25 psi. and clutch cuts out either from hi or low pressure cutout)

I need to change out the expansion valve. Can someone steer me to a reference with diagrams for getting to and changing the valve. I'm sure I can get there with a sledge hammer and crowbar , but if I had step by step instrucions I might get there with more finese and faster without removing extra parts. My Chilton's only says to leave it to "qualified service personnel"

Any help would be appreciated!

[Legacy777]

Welcome to the BBS.

The expansion valve is located right next to the evaporator core. Chances are there's a restriction, either in the expansion valve or other part of the system. I would recommend pulling everything out and flushing it, and then reinstall with a new receiver-drier, and if you can't verify the expansion valve is working, replace it.

You will need to have the system depressurized and should have the refrigerent captured. After that, you need to loosen the connections at the firewall that connect the AC hoses to the evaporator. Once those are removed, you can pull the evaporator box out. You need to remove the glove box, and there's two bolts/nuts that need to be removed and it should come out. From there you should see the expansion valve, and if you want, you can remove the ac hoses in the engine bay to clean them.

Here's some misc. AC pictures
http://main.experiencetherave.com/subaru/images/accomp/
http://main.experiencetherave.com/subaru/images/acevap/

[numberkruncher]

Josh,
Thanks! The info and pictures explain a lot.

What is the best way to clean all the mold out of the evaporator grid?

[1-3-2-4]

stupid question the 19mm and 32mm nuts does anyone really use a torque wrench on those? I expect O-ring in that area too? I forgot to buy a can of air today to clean out the evaporator as my expansion valve should be in tomorrow.

[Legacy777]

Depending on how bad the crud is on the AC evap, you may want to use a degreaser first......or brake cleaner. That shit works great.

Interdynamics pure air works very well at killing the moldy smell though. So once you've cleaned the evap core, dry it with compressed air if you have some or let it air dry after banging most of the water out of the fins. Once dry, spray it good with the pure air. Repeat a couple times on both sides and then reinstall.

Once installed, if you still have a smell, you can lower the blower motor to get access to the evap core to spray more pure air in there.

[Legacy777]

stupid question the 19mm and 32mm nuts does anyone really use a torque wrench on those? I expect O-ring in that area too? I forgot to buy a can of air today to clean out the evaporator as my expansion valve should be in tomorrow.

No, just tightened them to hand tight. Too tight and that'll kill the o-ring.

[1-3-2-4]

Ah ok

[1-3-2-4]

Does the 95 Legacy have the same expansion valve? I ordered from Rock Auto and they gave me the 4 Seasons part number 39124 and it does not have that tubing coming from the back of the valve to the evaporator pipe

[Legacy777]

Hmm....I'm not sure if the 95 valve is the same. Based on the picture, it doesn't have that fitting, so I probably wouldn't use it.

[1-3-2-4]

yeah it's not the right part

[91Beater]

How do I get the bottom half of the evaporator box off? I got the three clips on the front, then I reached around the back and got the two (out of how many i dunno) clips and one screw on the passenger front corner and one big bolt on the bottom, but it still won't come off completely

[Legacy777]

I replied to your other post in the body & chassis forum.

http://bbs.legacycentral.org/viewtopic.php?f=10&t=49650