ok here i go <img src="/forums/images/graemlins/lol.gif" alt="" />. first there is a dye for auto a/c systems,second it is checked with a u/v light.

as for as the overheating,i would let it sit with the front uphill for awile it may have air in the system.if that aint it check to see if the heat is working.yes i did say heat,if it isnt flush the heater core out. if the heater core is clogged the coolant wont circulate properly causing overheating.in order to do it place something under the jeep to catch the coolant and junk.if the jeep is high enough or can be jacked up high enough i would use a five gallon bucket.i would also get an old t-shirt and tie it over the bucket mouth like a strainer to catch whatever may be in there.then disconnect both heater hoses from the thermo housing. get an old piece of water hose and cut off the end that dont connect to the faucet.clamp a piece of pipe about 4 inches long into the hose leae 2 inches out.then slide the heater hose over the remaning part of the pipe and clamp it. take the remaning heater hose and aim it to the catch bucket/pan or whatever as someone turns the water on.it dont have to be on all the way,just a light flush at this point.when the water runs clear switch the water hose to the other heater hose and do the same. then go higher pressure on both heater hoses.when done check to see if anything came out like rust and such(that is what the t shirt is for).if there is alot of rust i would drain and flush the entire system.

also see if pressure builds up on the upper hose quickly(rock hard in like 20 seconds).if it does it will need a head gasket.

check the lower hose to see if it gets hot,if it dont the waterpump may be bad.

Fred first off do not give the head gasket any more consideration. The small amount of pressure in the system will not hurt the gasket any at all.
From the description I would think something has changed besides the a/c working. Did you do ANYTHING else to the engine?
But first thing to do is change the thermostat.
Big JIm <img src="/forums/images/graemlins/pfft.gif" alt="" />

BJ im not saying the pressure will cause the damage.im saying the blown head gasket is the cause of the quick build of high pressure. which will cause the over heating.
i belive with the ac not working before whatever causes the overheating now wasn't a problem.but now with it working the extra work on the engine made the problem"appear".
I do however agree that the head gskt should be the last thing to worry about,check everything else out first.

Well no luck, I swapped out the t-stat yesterday and drove it around and it seemed to be fine (it was about 70* outside last night though) but today while driving to the store in 90 degree weather it started overheating again all the way up to 230-240 range. It's not leaking from the cap anymore so atleast that's fixed, and it doesn't matter if the truck is just idleing or driving around at 35-45MPH, on a side note driving on the freeway at 65+MPH helped alittle but the coolest it got was about 220 degrees.

BigJim, I didn't do anything to then engine I just used a recharge kit, but I did take my truck to get emissions tested back on Monday. I gave everything under the hood a once over and it all looks fine. I'm going to swap out the waterpump tomorrow as it is only $30 bucks, even though it's not making that squealing sound that waterpumps like to do when they are going out as I am at a complete loss here. Running the heater on high seems to help a little as it drops the temp down about 10 degrees or so but it really sucks driving around with the heater on high in 90 degree weather. Any help appreciated.

Thanks again,
Fred R.

when you go t get the water pump buy some coolant flush also. dump it in the radiator and let the jeep run for awile,the instuctions should say how long. also find out if your jeep uses the long life coolant and get that pre mixed with water(3 gallons is what it holds i think).the long life coolant is used in alot of the new cars it has different chemicles in it that is more effeciant.if you ran the regular ethenol (green )antifreeze with the long life it may have cause the problem.it leaves all sorts of nastiness behind.
after you run the coolant system flush drain the system completly and flush it out with a water hose.i would also remove the thermostat before flushing,you dont want any garbage messing it up. then after all that is done
reinstall the thermostatand install the new waterpump then fill it up.let it run for awile then turn it off and let it set so any trapped air can escape.repeat until you cant get any more coolant in the radiator. i hope you get it figured out soon heat stinks.

I have never had a pump cause overheating except when they lost coolant. I have heard and seen photos of pumps that had rusted vains and could not pump enough coolant to keep up with the demand.
I have had a jeep six cyl with just about the same problem you are having. It was a carbed yj and the timing was not advancing enough. The retarded timing caused the overheating.
Big Jim <img src="/forums/images/graemlins/pfft.gif" alt="" />