Just had an AC clutch failure probably caused by a poor flush job when I redid the AC system a few years ago. The problem is getting to the expansion valve. Looking into this problem I have heard 3 things, not including those that say you should just take the AC off and throw it away. I need my AC here in Florida.

For getting to the expansion valve;
a- It's easy to get to under the glove box. This may apply to the early 944s?
b- You have to take the dash off to get to it. Which is what the manuals seem to say for my year. It's also what most shops price.
c- It's easy to get to under the hood. But AC shops and P-car shops in the area never heard of that. A search of this and other sites provided several references to this but mostly it is vague.

I did the job right this time and opened up access to the expansion valve myself before taking it to the AC shop.

1- wipers have to come off

2- remove the plastic plate over the fan housing. It's between the battery and the fuse box. I used a wooden stir stick sharpened on one side to pry it loose from the glue along the firewall. Lots of things should work but it will be easy to destroy this piece.


3- You are now looking at the top of the fan housing. It is held on with a bunch of Phillips screws. Remove the Phillips screws but not the hex heads that you see there also.


4- Lift the top of the housing up and lay it over the engine. It still has wires and hoses on it and will not go far. There is a smallish screened box on the right side of the housing base. Now you can even see the expansion valve under the screen. Side cutters will remove this mesh and you now have access to the expansion valve.



If you get after this, it should take less than an hour. I laid the top of the fan housing back in place and took it the AC shop that way. All I had to do was put it back together when I got it home.


You guys that are mechanically inclined or have experience may find this redundant. But hopefully some that are new to the expansion valve will find it helpful.
Woody

 

Great pictures and write up to get to the expansion valve on late 944s.

Thanks

John

 

I think you made it overly complicated. Why did you split the blower fan assembly and cut the mesh?

Do not remove the Phillips heads, remove the six 8mm bolts. There's three across the front and three more across the back. Unplug all the electrical connectors, lift up the blower fan assembly and disconnect the vacuum line from the bottom side. Remove the entire thing and you'll have better access than trying to get to it through the lower housing.

 

On the early cars you can unbolt/remove the evaporator assembly without removing the dashboard (and you must to replace an expansion valve).

 

Right. It takes about an hour or less to drop the entire blower motor/evaporator/expansion valve+++ housing on the early 944s or the '87 &'88 924S.

 

Are those cabin air filters just above the grating (in the upper half)? Are they cleanable/replaceable?

 

No, those are the recirculation flaps. If you want cabin filters, you'll have to get a blower assembly from a 1995 968. The upper housing assembly is still available, but the flaps aren't.

 

I know you have to replace the receiver/drier whenever the system is opened up and exposed to the atmosphere, but under what conditions do you replace the expansion valve? I thought you only did that if you knew or suspected there was contamination from metal particles in the system from a compressor failure or similar...

 

From a pro....Expansion valve failure
http://www.docsblocks.com/faq/E-93.pdf

John

 

Thanks for the link.

This seems to suggest that unless it has actually failed, it doesn't automatically need replacement (unlike the receiver/dryer)?

 

shouldnt need to be replaced unless its bad. It basically reads the temp of the suction line and decides how much of the liquid line to meter into the evaporator. When it clogs it usually doesnt feed right and closes or sticks closed. This will give you a high discharge pressure and a low suction pressure.

 

A/C experts tell me that it is more common for the TXV (thermal expansion valve) to stick in OPEN position, resulting in equal pressure readings on high and low side.

Problem is this is same symptom of bad compressor. This is my condition on my '87 944 S.

Please correct me if I am wrong - I am a mechanic, but not A/C mechanic. Just know A/C basics and can change components, pull vacuum, charge systems.

GN