2010 & Newer Coaches DEF Filter
If your coach has a Def system where you have to add Def, good chance you have a DEF filter. This filter needs to be changed every 3 years or 100,000 miles. I never knew mine had one until Monday when I asked about it and they replace it. Tech said filter looked bad when he pulled it out. My coach takes a Wix W74B191
On another forum a coach's def pump failed and his coach went into derate (max 5 mph). Turned out the filter was plugged and that caused the pump to fail.
Topic: 2010 & Newer Coaches DEF Filter