Expansion valve replacement?

2010 MAZDA 3
150,000 MILES • MANUAL
Avatar
BHAMDOC1
  • MEMBER
  • 280 POSTS
This is the 2.5p. I dont find the expansion vave. I changed the compressor and wanna change the expansion valve. I dont see anything where the lines hit the firewall. I know how they look like just not seeing it
Jun 12, 2026 at 7:55 PM
Advertisement
Avatar
JACOBANDNICKOLAS
  • ASE Certified Mechanic
  • 110,193 POSTS
  • ASE Certified Mechanic
Hi:

I just looked it up and it appears to be under the dash of the interior. If you look below, I attached the directions from my manual.

Take a look at the directions and let me know if they are helpful.

Take care,

Joe

See pics below
Jun 13, 2026 at 3:01 AM
Avatar
JACOBANDNICKOLAS
  • ASE Certified Mechanic
  • 110,193 POSTS
  • ASE Certified Mechanic
Sorry, I attached the pics below. I accidentally hit reply before adding them.

Take care,

Joe
Jun 13, 2026 at 3:03 AM
Avatar
BHAMDOC1
  • MEMBER
  • 280 POSTS
Installed it but i added some freon after and no cold air. The i thibk it was too much because the compressor never stayed on kept cycling on and off from too much freon. So removed the wxpansion valve because i believe its stuck cause no matter what i did it kept showing low. Compressor is new same for belt and now expansion valve. Anyways Well crap i stripped one of the bolts on the valve now it wont come off and the valve is half way loose, wont screw in either.so am sure i
Gotta remove the dash now to replace whatever housing it attaches to
Jun 13, 2026 at 8:02 PM
Avatar
STRAILER
  • ASE Certified Mechanic
  • 54,832 POSTS
  • ASE Certified Mechanic
Yep, I sounds like the evaporator core is now needing replacement. Let me know how it goes.
Jun 15, 2026 at 2:10 PM
Avatar
BHAMDOC1
  • MEMBER
  • 280 POSTS
You got any instructions just in case some stuff are easier and i dont overwhelm myself
Jun 15, 2026 at 2:31 PM
Avatar
STRAILER
  • ASE Certified Mechanic
  • 54,832 POSTS
  • ASE Certified Mechanic
Yep, I would start by removing the negative battery cable and then the steering column. This will give you a clear shot at removing the dashboard so you can get at the HVAC box. Also, drain the engine coolant because the heater hoses will ne dot be undone as well. This is a big job so take your time and upload any images of problems you run into and I will help walk you through them. Check out the images (below). Please upload an image or a short video in your response, so I can see what's going on.
Jun 15, 2026 at 2:49 PM
Avatar
BHAMDOC1
  • MEMBER
  • 280 POSTS
I was able to get it out using a set of bolt removal thank god. I installed it and same thing zero cold air with a new compressor and expansion valve. I can keep adding freon and it keeps cycling for 5 seconds then off for 10, when it does kick in the low pressure goes to highest point before the green, but adding freon does nothing to the gauge and not a hint of cooling at all...
Jul 2, 2026 at 4:27 PM
Avatar
BHAMDOC1
  • MEMBER
  • 280 POSTS
also when I relief the pressure at the low port using a screw driver all I get out of it is air, not freon
Jul 2, 2026 at 4:28 PM
Avatar
STRAILER
  • ASE Certified Mechanic
  • 54,832 POSTS
  • ASE Certified Mechanic
Did you vacuum down the system also let me know what the high and low side pressures are. I would go over this video as well.

https://www.youtube.com/watch?v=4EqdrBVb0sY

Let me know.
Jul 2, 2026 at 7:33 PM
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.
Ask a Free Question
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.