I have a Peterbilt 367 isx15 in my shop, that is not building air. I’ve replaced the air compressor per customers request with new from dealership. I’ve also replaced the air dryer, that came with new governor and filter. I have verified that all lines air clear of debris. I can let it run at idle and high idle for as long as I want, but it still will not build air. I verified, before replacing compressor, there are no air leaks on this unit. Does anyone have any ideas that would help me? Thanks in advance.
Disconnect the unload line from the compressor and make sure no air there. Leaking discharge lines are common, especially where cloth starts above trans right where the steel pipe ends. Run a new temporary discharge line from the compressor to the dryer and see if it builds.
