I've had my '04 since new and over the past month or so, the AC has gotten weaker and for the past week hasn't really lowered the temperature. The compressor kicks on and runs. I went to have a diagnosis and was told the compressor is bad and will need to be replaced. The shop also suggested that the evaporator and expansion valve also be changed. Total quoted price ~$1300. The majority of that $900 is the expansion valve replacement since it's in the cabin and harder to get to.

I've researched online and the compressor replacement is pretty straight forward, something I could do myself pretty easy. The vacuum/refill will be harder, but I have a friend that could help with that. If I was just needing the compressor, I'd do everything myself and refill.

My question is: Should I follow their recommendation and also replace the expansion valve and evaporator? I'm told a failed compressor would put debris in the system which would damage the new one if the evaporator and exp valve aren't replaced also. Just wanted to check with others who knew before committing to replacing everything.

I'll also get more quotes.... I know there are used options also here on the FS sections.

 

Did they actually do a leak check? They should have checked the pressure and, if it was low, added some dye and extra R134a. Come back a few hours or days later with a UV flashlight and search for where the dye shows up.

Theoretically, they are right and it's good advice. If the seal(s) in the compressor went bad and allowed material to infiltrate or came apart into the refrigerant system itself then it could cause problems with the new compressor. I don't know how likely this is but it would suck to ruin your new compressor.

Honestly, if it were me, I'd check the system pressure. If it's low, I'd add some dye and refill it with one of those kits from Autozone (or wherever) that include the pressure gauge. Run it for a while and come back with a UV flashlight and see if you can find where it's leaking from. Either address that leak or, if it's slow enough (takes a few months to become a problem again), just add some leak sealer and refill and check again in a little while.

 

They wouldn't tell me the pressures yesterday when I got it checked. They were happy to change my compressor though. I bought one of those refill kits from Autozone figuring another $44 wouldn't hurt considering the quote they gave me. When I checked it, the low pressure side was low (~10psi). I filled it and it's blowing cold now. We'll see how long it lasts, but now I'll know if it has a leak and how fast or slow that leak is now that I have the ability to. Our systems only hold about 16oz of refrigerant which is the smallest amount in the mazda fleet. We'll see how long it'll last now.

Thanks for the advice.