Changing AC expansion valve 2005 Mini Cooper S Convertible (R52)

Symptoms: AC not blowing cold, system confirmed filled with R135; Low side reads high, high side reads normal. Low side drops when compressor kicks in, high side does not move.

Diagnosis: Expansion valve stuck closed, preventing any flow of refrigerant.

Task: Change expansion valve.

I bought the valve from Advance Auto for about $41. You can get them on eBay for about $20. Prolly the same part.

Review the pages from the Bentley manual. It’s pretty straightforward and the manual is clear. Start by emptying the AC system.
Page 1
Page 2
Page 3
Page 4
Page 5

1. Remove air cleaner box: This took a little wedging and maneuvering. Don’t be frightened: it all comes apart

2. Once the air cleaner box is removed, take the time to move everything out of the way that you can. I used a web of zipstrips to pull cables, hoses etc away from the expansion valve area. If you don’t do that, the job is gonna be a lot worse than it has to be.
Web o' zipstrips 1
Web o' zipstrips 2

3. The expansion valve is on the firewall, under the lip behind where the air cleaner box sits. It’s hard to see, but it’s there.
It's under there
This is what it looks like from the engine side of the firewall

4. Remove the two 10mm bolts that hold the lines to the expansion valve mounting block.

5. Move the two lines away: the small one easily drops below the valve block, the large one can be pulled to the side with zipstrips.

6. Using a T25 torx screwdriver, remove the two long screws that attach the mounting block to the expansion valve. The screws will be tight - I had to use a wrench on the torx screwdriver to break them loose. Be careful: If you strip them, the job gets a lot harder….
Using a box end wrench on a torx screwdriver to get the mounting screws out

7. Move into the car and remove the trim panels as detailed in the manual.

8. Remove the valve retaining plate and pull out the valve

9. Replace all the O rings on the retaining block with the new O rings that should have come with your new valve
Should look like this.....

Installation is the reverse. The one MAJOR thing I would add is that when installing the new expansion valve, use a couple of zip strips to keep the lock plate in place while you thread the two mounting block screws into it. Otherwise, it moves, and you’ll never get the two mounting block screws in place.
This is how the plate goers on
Using zipstrips to keep the plate on while I screw it together from the other side

Happy to answer any questions: ken -at- blakelys -dot- us