Besides (1) a bad fan clutch, (2) could be entrapped air in the cooling system, or just a bad radiator (even if it was chemically "cleaned"). Could also be bad cap on cooling system, or bad thermostat.

If mine, I'd start by testing (1) and (2).

 

shoudnt be a bad radiator i changed that at 215k im going to change the clutch fan regarless since the truck has 226k miles most parts are oringal.

 

i flushed it 25 k miles ago. New radiator. Going to replace the fan clutch. Due to the High miles of the truck

 

Change the fan clutch, not the clutch fan !!!

Radiator likely OK as you don't run hot at faster vehicle speeds, air rams through the condenser and radiator then.

 

Replaced the fan clutch and its still showing the same problems. The radiator i replaced 20k miles ago and flushed the cooling system when i replaced it. Thermostat?

 

Now go to (2). Cap and thermostat are inexpensive. Question: the fan shroud is present and correct type, right??? You are using about 50/50 coolant/water, right? When you changed the radiator at 215K did you get a heavy-duty one, or one for a small truck??

Might be getting to where you visit an independent ASE mechanic to let a second set of eyes look at it.

 

radiator i got a good big one nothing cheap spent 200 + on it colent is good. Thinking its thermestat since the uper radiator hose it hot to the touch

 

The fan clutch and radiator approach didn't help you, but I have a hard time understanding what the thermostat has to do with the AC. I too had an AC problem where it would run cold then hot then cold again until finally one day it would not blow cold air at all. The compressor would run but no cold air. It turned out to be a valve on the high pressure side that had developed a minute leak. Once replaced, the AC blows cold all the time; up till then a Freon charge might last a month or two before it leaked out. They had a heck of a time finding the problem as a result. Yours could be heading in that same direction.

 

From what i was reading some forums said that thermostate did have something to do with warm air once it started to heat up. How many valves does the suburban have?
should i also replace the high and low? A delco one on amazon is 4 bucks
But would that cause the over heating as well?

 

What is going on is two separate issues. Yes, a good thermostat will aid in warm air blowing and help keep the engine from overheating. But where having the AC on will put additional load on the engine resulting in possible overheating, the thermostat, good or bad, should have no affect on whether the AC blows cold or not. Like I mentioned, having that valve on the high pressure side replaced fixed my AC and there has been no problem since, yet up till I did the radiator flush having the AC on seemed to make the engine's cooling ability inadequate. The only fix was to turn off the AC and turn on the heat, after which the temp gauge would drop to where it belonged, about 190 degrees. How many valves does a Suburban have you ask? I am GUESSING one on the high pressure side and one on the low pressure side, but I really have no clue for sure. I just know that what they did worked. I regret to add that when temps hit 97 in my area recently my gauge started climbing again with the AC on at idle. Very disappointing; and all I can think of is maybe my fan clutch is going again...it does have 244,000 miles on it. And being that i did the flush and sprayed the fins out there isn't much else that it could be. I also hear a gurgling sound when I first accelerate after initial start up. It seems to come from the heater core area. I believe the problem is that area is a high point but there is no high point vent to bleed the air out so it just travels through the system till the engine is turned off, where the air finds it way back to that same high point near the core. I bought a Prestone flush kit some time ago with a T shaped piece that you cut into the heater hose near the fire wall. It is for a hose to be hooked up to aid in flushing the engine but it can also be used to burp the air out of the system from that same high point I presume...maybe. The only other thing that might be a problem in our vehicles that I can think of is a vent damper that isn't working properly. Mine seem to work but they seem to be stuck for a second and then open or close loudly. It is quite the adventure keeping this old boat afloat, but I sure like not having payments.