Prevost level low?

[robertglines1]

On my current project build : 98 XLE the level low valve body in the front steering compartment has the red caps missing off the ends of the spools . When the coils are released on a spool a puff of air is discharged. What is the intended function of these missing caps? Vents? plugs? the ends of the spools are threaded.    Bob

[robertglines1]

Just got answer from a friend. they are vented and deflect air to side. So I can put that one out of mind.    Bob