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Discussion Starter · #1 ·
My 97 Suburban LT is close to being sent to the scrap heap. I've been running a long thread on another A/C specific forum, but after replacing nearly the entire A/C system, piece by piece, I'm stuck with 70+degree air coming from the front vents. Rather than post the entire thing again here, I ask that someone take a look briefly at what I've done already and posted on the acsource.net forum.

http://www.acsource.net/acforum/viewtopic.php?t=4517

A short synopsis reads:
I've replaced:
Compressor, (three times, two defective replacements)
Pressure and vacuum hoses attached to same.
Condenser
Orifice Tube
Accumulator (twice since I had the system open so many times)
front evaporator (ruined when not able to remove accumulator)
Rear TXV valve
And yes, I have some familiarity with A/C systems although I'm not an expert. I vacuumed the system each time, and carefully measured oil when replacing the compressor and accumulator.

Have 56oz refrigerant in system and 50psi/250psi at 87 ambient idling with fans on condenser and 40/200 driving at 45mph. Lowest front vent temp is 70deg.
 

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the compressors that you are buying,are they remanufactured? or is brand New?iv got 98 tahoe thats got a clogg in the ac lines and i gotta find it and then i got to replace a stupid hose thats connected to the ac system,but on my 97 cad.seville i went thru 2 ac compressors till the 2nd one worked.they were remanufactured,so i wonder if they are not as good as a new one?well i hope this helps.:neutral:
 

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Kyle.....I think you may have a couple of things that you hit on....1- if the compressor came apart, you may have a blockage, frank....have you replace the filter, in the a/c line. You may have to blow out or replace the front a/c line . You might have pushed it into the Evap?

2- have you checked the "blender" door, that may not be closing to seal off the heater core, in the front. You may have a vacuum leak or a malfunctioning servo.?
 

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DJ's item #2 came to mind when I looked at this. Since you have cool air at the rear, this makes sense. (To me at least)
 

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Discussion Starter · #5 ·
How can I check the blender door? I've disconnected the heater lines and it didn't change the temps, but that may not matter if warm air is 'leaking' past the Evaporator.

I've replaced, and or cleaned everything downstream of the compressor. I've replaced the orifice tube three times. Now I'm sure it's clean. I've got fairly good pressures 250lb and 50lb idling at 90deg, but no cool air in front.

Is there some way to test/move the blender door without removing the dash? I know the heat works, as I checked last night while driving, and it quickly got to 100deg in the vents.
 

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well DJ thanks for the info.im sure i gotta replace the hose cause it was leakin(low pressure side) and i cut it and spliced it hopein it would hold but it didnt so i have to either have a machine shop put it back together for me with one of those special clamps they use(stock) that they use a machine to put it on with and then my other issue is the blockage,my rear gets cool but the front stays pretty warm,i know the compressor works,my buddy that works at a shop tested it,how do you clear the lines and system out?

thanks

kyle
 

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Franklin, I can feel your pain...

Mines not quite as bad as your's but I'm having almost the same problem with my 'burban.

With mine the rear is cold, to the point where people complain, bring their own blankets, gloves, ect. However the front needs to be on high all the time, 24/7. I did find if I turn it to low for a minute then up to med it blows cooler, for a while.

Anxiously awaiting your good fortune to happen soon...
 

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The blender door can be reached under the dash, if you remove some of the lower sound shields and squeeze to the top of the Eva/heater core case. You can move it to insure that it is closed.

After reading some of the other comments, I remembered one more thing. The cowl, fresh air inlet, which is in the cowl, under the ridged vent. There is a servo there that should close, when on MAX air. If that is not closing you would also get a situation as the blender door not closing.

You can be certain, that short of a blockage to the front evap, and the rear is cold, the AC system is working fine. Your problem lies in "outside" air getting in.

If you fill the system with the correct freon, and you had a blockage, you would have high pressure readings....

Hope this helps
 
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