Maxxforce 11 uploader problem

How do I test the uploader mechanism on a 2013 Maxxforce 11? Makes a lot of noise when building air pressure and then all noise stops when air dryer pops off. Air pressure drops and the compressor seems to always be building air. I have info on older Bendix compressors (TF 550) that says to apply shop air to the unloader port on the governor and capture that air pressure with a shut off valve to see if air pressure falls. Same with these block mounted compressors? This compressor was diagnosed by a dealer 6 months ago as bad but they wanted $7k to replace it. Ordered a new IH compressor on-line and installed it myself. Was at the dealer for another air problem later and was told the compressor was good. Now the noisy uploader (I think). Will the compressor still be under warranty since I installed it myself? How would I do that? Thanks for any help.