Loosing air pressure overnight

[mrktrain]

I recently started loosing air pressure after parking for overnight. At first it was slow, a few psi overnight, but now it's "zero" the next morning. I've also noticed it takes longer for the air charge to build up to drive pressure when first start up. It also stops building at about 90psi unless I increase engine idle speed. I suspect it's a PPV but I don't know how many or where they are located. Once I locate it/them, just check with a soap and water mix? Can they be rebuilt or are they throw away items? 

 

2006 Diplomat

[miacasa_2000]

Not sure of your coach I have 4. 2 on each tank (front , rear)  I replaced mine a few months ago got them from advance auto for $15 each. Too cheep to rebuild I also replaced my fittings with swivel type so if these cheaper one fail prematurely I don't have to keep pulling, cutting, etc. the air lines. That being said they are well made and used in the trucking industry.  ( World American  pressure valve WAKN31000 ).

My suggestion is to air your coach all they way up and and secure it by a safe method don't go under with out that . Then get about a 1/2 gallon of kids bubbles and put it in a garden sprayer and spray the heck out of every thing. As fast as your dropping you might find more then a ppv.