Tahoe 2011 A/C problem

Hi guys,I need help. I have a 2011 Tahoe with an A/C problem. Let me tell you what happens.When the car is cold and I turn on the A/C, everything works fine. After 20 to 25 minutes, the problem starts: the compressor clutch starts disengaging and then engaging again. Because it only stays engaged for a short time, the A/C doesn't cool very well.I checked the pressure, evaporator, ambient, and coolant temperature sensors, and all of them are reading normal.Can anyone help me with this?

What are your High and Low pressures doing when the compressor cycles?

First of all thank you for your reply.
When it's normal the high is 250 psi and low around 40 psi. But when the problem comes it's reach 200 psi the high and around 70 psi the low. And the compressor will disengaged and it repeated.
The compressor, condansor and the orifice are new.

I'm a little unclear on what the cycle is. What are the pressures when the compressor shuts off? How long does the compressor stay off for? What are the pressures when the compressor kicks back on?

After the Compressor and Condenser were replaced, how much oil was added to each component? 

I am wondering if, maybe, you have moisture in the system. How humid was it when the system was open? Was the system properly evacuated with a vacuum pump? How long did you keep the system under vacuum? 

Does this vehicle have Rear AC?