1999 Tahoe rear air started blowing warm

[Chester King]

Early in the season I put three cans in and got her going, the rear blew ice cold for several weeks and the front was just doing 75 %. Now I only have the front. I am suspicious of the oriface tube being plugged. It is an auto rear ac, no temp control. thanks in advance for any input

 

[exp500]

Well, you have done 1 step of diagnostics, Recommend you put gauges on it and look for leaks.