2006 frightliner when I build max pressure it doesnt release all at once

Maybe the safety valve mounted on the compressor head, is what you’re hearing, not the air dryer spitting. Maybe the Govenor needs adjustment, or the safety valve is weak. New air dryers sometimes spit for a long time, then break in and spit quickly. I’m confused why it spits every 2 minutes at idle, then won’t while going down the road. Never had that problem. Always a bad Govenor, spitter on dryer or bad safety valve on compressor. You say cut out/ cut in pressure is normal at idle. Yet it spits every 2 minutes. Any air leaks maybe? Sounds like maybe the Govenor is set too high, or the Safety valve is weak, and leaking a bit. When going down the road at higher RPMs you don’t hear the safety valve leaking, and compressor is pumping air faster than the valves leaking. Dryer and Govenor both being fairly new. I would make sure the rapid spitting at idle is coming from the air dryer, to rule out the safety valve. Post the cut out/ cut in readings from the gauge. Hopefully someone can help you figure it out.

 

Well, first thing I’d do is adjust the Govenor to cut in and out at 100/120, or 105/125. I’m only guessing the purge spring is getting weak, from purging at a higher compression. That’s only a guess. I don’t know much about it all. Just always change Govenor, air dryer, clean system with conditioner and drain tanks a few times. Last time I did mine, after freezing up, it acts funny for a day or 2. All I can suggest, is adjust Govenor, pour some air brake conditioner into the line off compressor. Run it, Drain tanks at least a couple times times, till they’re clear. Maybe clean the spitter on dryer with brake clean or ether. Might be some trash in the spitter valve. I believe the dryer and Govenor on your Truck are expensive. Depending on results. You may need to replace or rebuild the spitter. May need a new Govenor. I would try to adjust it first. Clean system, see what happens. I don’t know much more to do. If that don’t fix it, someone else may know more.