Front a/c cold, rear a/c not

[122andy]

I'm pretty sure my rear a/c worked last summer. This year it is blowing out the roof vents, but the air is ambient. The front air is cold. So the the flapper or whatever is in the back works, as when you turn it to heat it blows out the floor. So...I have airflow and the front works. What gives? Ideas?

 

[JohnnyBfromPeoria]

Not anywhere near sure I can help, but please tell us what year Montero you drive.

John B.

 

[122andy]

Sorry, it's an 2002 Limited(see profile pic) It just makes no sense that there is ambient air blowing out the roof vents. Blower is working, flapper is working, no blockage anywhere. The rear is tied into the same lines as the front as far as I can tell. That would be the only reason I can think that it's not blowing cold is that it's low on refrigerant, but the front is super cold.

 

[122andy]

Best I can figure out is possibly a bad rear expansion valve. Maybe it's not opening and letting any refrigerant thru.

 

[122andy]

Well it doesnt matter now, I had to run the spare due to a right rear flat. Eveything looked pristine on the spare, no cracks, inflated properly, etc. A couple days later it delaminated at 45 mph, ripping out the rear heat/ac unit, totaling the Montero. All because these damn things are so hard to find and they couldnt source one used. A new complete unit from Mitsu is $2200. So the plan is to buy it back. And say to hell with the rear heat/ac until I can source a used one, if not, nbd.

 

[coffeegoat]

Crap man, sorry to hear that. I'm actually hoping for a nice hail storm to total mine out since the paint is already terrible but it's still a hassle...

 

[2to4wheels]

I'm having the same scenario with my '06. Rear blows based on fan speed, just not cool when the front cools pretty good. Would also love some suggestions.

 

[122andy]

The only thing I can think of on mine is maybe the the rear expansion valve. Btw I sourced the whole unit from MS Recycling out of CA for $175. That's for everything hanging underneath....heater core, ac condenser, the whole thing. I highly recommend MS for any of you guys looking for parts considering these things are so damn hard to find.

 

[2to4wheels]

I think mine might be the rear expansion valve as well. At the "T" in the engine compartment, one set of lines is nice and cold (front) and the rear lines are nice and warm.

Where would I find the Expansion Valve in the rear? Is it underneath or behind body interior panels?

 

[122andy]

Solved. Refrigerant was low. I ran it by my only trusted mechanic, told him what was going on. Basically it had enough in it for the front to work but not the rear. Go figure. I honestly dont know how the front could work but not the rear considering they are sharing the same refrigerant, but after pulling a vacuum and recharging, rear works great now.