Problem with A/C on 2000 Suburban

[Lost-Bunch]

I have a 2000 Suburban that the A/C is driving me crazy. Last year I replaced the belt tensioner three times, last one was from GM dealership. They are over extending and coming in contact with the A/C compressor. The front A/C works great, very cold, the back however does not work. Checked in the back panel and the flapper is directing the airflow correctly, so I guess there is no freon getting to the back. Had gauges put on while the tensioner was contacting the A/C pulley and pressures looked right on. My question is, do I need an all new A/C system or could it be just a clogged orifice going to back causing over pressurization of the system ??? Thanks for any thoughts you may have. I would rather not have to replace the hole system (compressor, dryer,) if i don't have to.

[truckdude239]

the back uses an expansion valve have you tried a new belt on the a/c?,

[Lost-Bunch]

Yes, put several new belts on, even one that was a little shorter. What seems weird to me is the fact it works great, put a new tensioner on and it will last about a week or two then over extends and breaks the belt. The compressor makes no funny noise's unless the tensioner is contacting the pulley. The local A/C repair shop said to replace the system around for 1000.00 but they can't tell me whats wrong with mine ? They are the ones who put gauges on it and said it looked fine, but said that the compressor must have something wrong with it and clogged the rear expansion valve.