tcmwhite Report post Posted May 14, 2015 I have a 2009 Winnebago. My air dryer keeps blowing off air only while I am driving. It blows off for a few seconds and then stops and starts again in another few seconds. I replaced the purge valve, air dryer filter, governor and supply line from the governor to the air dryer. I know my unloader valve in the compressor works cause I can hear it cycling and notice the air changes. Is there something I am missing? Thoughts???? Share this post Link to post Share on other sites
wolfe10 Report post Posted May 14, 2015 tmcwhite, Welcome to the FMCA Forum. First question: Does coach air pressure cycle that rapidly between CUT-IN and CUT-OUT PSI? If so, look for a large air leak (i.e. the dryer is doing it's job-- purging at the end of each compressor-run cycle). Share this post Link to post Share on other sites
obedb Report post Posted May 14, 2015 As Brett said. There is a leak somewhere. Often the air dryer IS the culprit. When the compressor cycles off, the dryer purges. A tight system can go quite a while between purges. Get out the soap sprayer if you can"t nail it down quickly. Retired trucker familiar with the problem. Byron Share this post Link to post Share on other sites
Miramichi Cruiser Report post Posted June 2, 2015 As Brett said. There is a leak somewhere. Often the air dryer IS the culprit. When the compressor cycles off, the dryer purges. A tight system can go quite a while between purges. Get out the soap sprayer if you can"t nail it down quickly. Retired trucker familiar with the problem. Byron I second this. Any update? Share this post Link to post Share on other sites