just bought 04 lly. ac not blowing cold enough. took it to the dealer they said after checking everything that it was the compressor. a new one is 695.00$ i got a 15% discount because we take our work trucks there. i bought it and had guy from work put it on, he does all our ac work. the proper amount of freon and oil was put in. still not working and im really pissed. they wont give my money back. what could be the problem? ive read all the threads but i havnt seen anybody with same problem.

Do you have a good ac man???
Does it have pressure what is it doing???

DO you have a orfice tube in it????

Neede more info!!!!!!!!

David
:cool2:

the dealer said the orifice tube was dirty and they cleaned it. our machine at work said it had the right pressure in it we put the right amount of oil and freon in it, according to gm specs. when it gets in the mid 80's outside temp. it just not cool enough. we installed a new low pressure switch also. the machine doesnt tell you if the accumilator is bad or other parts could be bad. has anyone had a similar problem and what did it take to fix it? thank you.

Double d 1
If the old compressor destroyed itself there is a high probability that the accumulator is contaminated and must be replaced.
If the system lost it's gas and was open to atmosphere for any period of time between the first compressor failing and the second being installed you could also have excess moisture in the drier/accumulator. If that is the case then you should have had the entire system on vacuum for as many hours as practical to eliminate that moisture (by evaporation) before charging it with Freon. If not then it could be excess water vapor in the system. If so your best bet would probably be to replace the accumulator/drier.

Did you check your low/high pressure limit switch?

One would hope your A/C guy would have covered these points but it never hurts to ask the questions again.

when replacing a compressor on any AC system the following should always be done to ensure a successful and long lasting repair.
1) before adding new parts, the hoses, evaporator, and condensor should be flushed out to remove contaniments.
2) orfice tube should be replaced, you can't clean them properly.
3) Dryer/accumulator should be replaced.
4) replace all o-rings in the system with new ones.
5) replace schrader valves if applicable (usually on charging lines, and under high & low pressure switches)
7) add new oil to system (amt determined by mfg)
6) using vaccum pump, pull vaccum on system for as long as applicable, then make sure it will hold a vaccum (leaks are present if it won't)
7) add proper amount of freon using charging machine that weighs the gas put into the system. (You can't use guages to determine the proper charge in these new systesm)
8) start up vehicle and engage AC compressor......... let it idle (with a shop fan pointed at the grill) for 10 to 15 minutes to break in the new compressor........ don't rev it excessivly.
9) enjoy you new cold ac :)

If any of these steps are skipped, you are putting that expensive compressor at risk and may have to buy a new one and do it all over again.

Harry

DoubleD -
the problems you are encountering are very common with today's techs (whether independent or dealer). Follow everything that SeaRay recommended and do the following to troubleshoot the cooling problem -

1. What are the gauge readings while the A/C is on (low or med), all windows closed, and in the recirc. mode ??
2. Insert a thermometer into the vent closest to the evaporator (usually the center or off-center vent of the dash). What are the temp readings with a fast idle (1500 to 1800 rpm (they should be in the 40-50 degree range for max cooling)??
3. The compressor should not cycle if you are trying this on a hot day (80 degrees and up). If it does, note the pressure cut-off on the suction gauge - it should only shut off due to high pressures (usually overcharged) or low pressure (usually undercharged).
4. GM compressors are extremely reliable and it is most unusal that a late model compressor "just goes bad" because there will be a lot telltale signs (reduced cooling, cycling all the time, dirt accumulations around the fittings with O-rings, etc.). It is possible that the tech that installed this compressor is not certified in AC.
5. Late model GM trucks will take about 2 - 3 pounds of refrigerant. Any air or moisture that is taken in during the initial charge of the system will greatly affect the efficiency of the unit.
6. If you know an AC tech with an "electronic sight glass", hit him up for a diagnosis with this gadget. I own one as I used to do AC work for many years. What this unit does is "read or detect" air in the high pressure line much in the same way as the sight glasses that used to be installed in most vehicles for years. Two metallic clamp probes are placed on the AC high pressure line just befor the orifice tube. This is where you should have solid liquid (without air bubbles in the system) for maximum efficiency.
7. My bet is that the AC tech is lacking in experience and over-charged the system. Late model GMs do not take to dumping a lot of refrigerant into the system all at once. You have to have many years experience to do this just right with damaging the compressor (by the way, any knocking at all coming from the compressor while it is running??).

As you might be able to tell, I can diagnose this for you if you can get me the information above (I did this type of work for about 20 years). Let me know or pm me with any other questions or information that might help.
LOL :):)

the dealer said the orifice tube was dirty and they cleaned it.

HA. thats a good one. funniest thing i've heard all day. another thing to check is airflow across the condenser. if there is no airflow, the system wont cool properly.

All great idea's BUT you forgot one thing and it is only a preference thing!!!!!

I have used with great sucess Copland Syn. oil
I think it would doubble the life of your a c.

David:cool2:

Double D

Have you resolved your AC problems yet? Let me know if you have any answers to questions.

well i appreciate everyones replies. the guy at work doesnt know any more than the man on the moon. it sounds like ill just have to look around for a qaulified ac man. the dealer didnt seem to know that much either. ill just hav e to get some referances from some knowledgeable people. ill take some of these replies with me to put them to the test . thanks everyone ill let you know how it goes.

well i finally got a new accumilator installed. its working alot better now. drove about 190 miles to go atv riding with 6 year old son in 100 degree heat and he kept saying to turn it down. stopped one time to go in a motorcycle store and i left the truck running for about 10 minutes and got back in and it was blowing warm air, soon as we got about a block down the steet it was working fine again. thanks for everyones help.

You my have a air flow problem through the condensor or the fan , they cool the cabs very well when working the way they should.

Have the same yr truck and the same problems. The Accumulator fixed all the probs.