my front brake air tank continues to lose air, and when parked, within 30 minutes<br/>the front drivers side has dropped down onto the tire. i have replaced both check valves<br/>and both protection valves and stopped all the little leaks . i think the leak must be in<br/>the six pack. i am not going to rebuild the solenoids, i am going to replace them. <br/>my question is are all the...