Detailed Procedures to Adjust Ride Height
I've searched all over this forum and others and have not located a detailed step by step instruction on how to adjust the motorhome ride height. There is plenty of info on how the ride height should be set, i.e., 8" or 8 1/2" depending on where one measures. What the ride height valves look like and where they are located. How to adjust the valves to put more or less air in the air springs/bags. But no step by step instructions from beginning to end. So this is what I think should be done. I have not tried this. Your comments and concerns are appreciated.
1. Start the engine and bring up the coach air pressure to blow off. Check the air gauges to ensure proper pressure (~ 110 to 120 psi) is in the front and rear brake air tanks.
2. Retract any slides that have been deployed.
3. Place the coach in travel mode by pressing the Travel Mode button on the HWH control panel. If the green light does not light, press the brake pedal and release the parking brake. If the Travel Mode green light does not light after releasing the parking brake seek help from MOT, FOT or this forum.
4. If need be, drive the coach to a place where it can be parked on a fairly level surface. After stopping place the transmission in "N" and set the parking brake. Block the coach wheels for additional safety.
5. Measure the ride height at four points. I use a carpenter's combination square. In front, select a point near the air bags behind the steer tires. In the rear, select a point near the air bags in front of the drive tires. Note that the top and bottom of air bags are attached to horizontal steel frames. The correct ride height is 8.5" between these two horizontal steel frames. Proceed further if you need to adjust the travel ride height.
6. Before you proceed, you will want to note each ride height valve control rod position in relation to the valve body. Take a picture, use a marking pen. The rod's position in relation to the valve body denotes that the ride height valve is closed.
7. On the HWH control panel raise the coach so that each corner is about 8.75" to 9" measured at the air bags positions listed in #5. Raising the coach will disable the travel mode function and the ride height valves.
8. Insert 4x4x8.5" blocks or equivalent next to the four corner air bags. In front select the bags behind the steer tires. In the rear select the bags in front of the drive tires.
9. On the HWH control panel slowly lower the coach frame until it barely touches the tops of the blocks on each corner. This process will require two people. One person to operate the HWH control panel and one person to observe the coach lower process. Please note the coach is not in travel mode at this time. Since the coach is not in travel mode, the ride hight control valves are not operational.
10. Inspect each ride height valve, two in the rear just behind the drive tires and one in the front between the steer tires. The rear ride height valves control side to side measurements and the front ride height valve controls front to rear measurements. I read somewhere that the front to back measurement is kind of critical since it controls the angle of the driveshaft between the transmission and the differential.
10A. Each ride height valve has a metal control rod/arm that sticks out perpendicular to the body of the valve. The rod/arm is attached to a vertical stem that is connected to the lower frame of the coach. The position of the control rod in relation to the valve body determines air flow to the bag(s). When the control rod/arm is in a horizontal/perpendicular position to the valve, the valve is closed and no air can enter or exit the air bags controlled by that ride height valve. PLEASE NOTE: I MAY HAVE THE FOLLOWING INFORMATION BACKWARD: If the control rod/arm is pushed up by the vertical stem, the ride height valve supplies more air to the controlled bags. If the control rod/arm is pulled down by the vertical stem, the ride height valve exhausts air from the controlled bags.
10B. One by one inspect the control rod/arm position of each ride height valve. If the arm position is not horizontal/perpendicular to the ride height valve, the valve needs adjustment.
11.. Turn off the engine if you want to at this time.
12. Adjust the ride height valve(s) by loosening one or both of the two clamps on the vertical stem (ref #10A) placing the ride height control rod/arm in a horizontal position relative to the valve. Ref #6 to get this measurement as close as possible. Doing this will close the ride height valve turning off the air to the controlled air bag(s). Retighten the clamps ensuring the metal vertical stem is clamped between the rubber stem and the metal rod/stem.
13. Start the engine and bring the air system up to blow off.
14. At the HWH control panel press the ALL raise button; remove the four blocks.
15. After removing the blocks press the travel mode button on the HWH control panel. This procedure will activate the three ride height control valves which will deflate the bags till the ride height valves reach neutral. You should be able to hear the air being dumped out of the bags. On my coach the rear dumping process finishes before the front. Since all the valve arm positions have been adjusted to horizontal/perpendicular, the HWH system will assume the coach ride height is correct. Measure the distance at each corner to ensure the coach is at proper ride height.
16. Drive the coach around the block and recheck starting with #4.
Topic: Detailed Procedures to Adjust Ride Height