98 Tahoe fnt/rear a/c problem

[plh_in]

Anyone have any ideas why the rear a/c is blowing air much colder than in the front vents?

Is there a flapper somewhere that is not opening/closing properly or ?? Any help would be appreciated....getting ready for a trip & I will not be able to withstand the complaints w/out cold air up front!!!

Thanks!

[krewl1]

I to have the same problem. Any solutions would be helpfull.

[ruddog]

same here my 97 started doing the same thing. Nearest I can tell the front is warmer becuse its mixing heat with the ac. what i noticed is that if i turn of my ac and just run the vents. the front still blow out much warmer air the rear vents.

[plh_in]

After having the lines blow out fwds and backwards, the front is now blowing cold air. Evidently, there was some type of obstruction in the line somewhere????

It took ~150 in labor plus the coolant, ....but, I have cold a/c for my vacation travels.....

[bustedratchet]

One possibility is the front orfice tube may be starting to clog while the rear expansion valve is free flowing.

[krewl1]

Not to sound to unknowledgable but where is the front orifice tube located. Could my problem be where it t's off near the firewall and drier? After studying the AC lines under the hood it looks like it splits at a T where I think one line runs to the back AC and the other goes to the drier for the front. I figured the restriction would be near the T. Correct me if I am run on any of these assumptions.

Thanks

[bustedratchet]

Look for the smaller line from the condensor to the firewall leading to the evaporator. A lot of times on Chevy trucks it is in the condensor behind/below the right light.

[krewl1]

Well here is how I finally solved the problem. Thanks go to the people that helped me look in the right direction. I first removed the drier/accumulator (silver round container by passenger firewall). I then removed the small line right below it which was leading to the evaporator. I blew out the lines to make sure there was no obstruction there. I then disconnected the small line leading to the condesor which is located behind the passengar running light in the grill. I then blew that out both ways. I then found the orifice tube which was located directly under the air filter in the ac line. It is in the same line that we just took off. I used needle nose pliers to get it out. I figured since I was there I might as well replace the accumulator and orifice tube and then recharged it. Easy way may be to take the orifice tube out first to see if it is clogged.All is well now. Hope it helps someone down the road.

[Hightech]

99 with exact same problem, checked r134a pressure this weekend and looks good, have to look into this, rear air is very Cooooold.