I have had this issue for a while and I am finally trying to solve it. Symptoms are as follows.
Driving in town and I will pull up to a stop light and notice the front is low. I then put on the park brake and take my foot of the brake. When I do this the truck will level out, sometimes in 10 seconds but sometimes longer. If I drive all the way to work without performing this procedure when I park the truck it will level once I put it in park. Sometimes the rear will move around while this leveling is occurring almost like a seasickness motion (like the bags are inflating in a circular pattern).
Before we start I will try to answer as many of the possible questions that I can.
- Driver module replaced - same symptoms
- No leaks detected on bags or lines.
- Valve block rebuild 3 times in last 3 years.
- Replaced all o-rings on bags and dryer.
- Swapped height sensors and replaced one where tab snapped off due to rust.
- Calibrated EAS using dowel blocks.
- Truck does not drop at night. Sometimes raises while parked.
- Truck does not move if relay is removed.
Any help with this would be great as drive-ability is an issue.