# Air Suspension

## Introduction

Click to enlarge

The rear sir suspension system is an available option on the F-250, Expedition and Navigator. The 4-wheel air suspension system is an available option on the Expedition and Navigator. Every component is nearly identical, except for air shocks, which are only equipped on the 4-wheel air suspension system.

## Air Compressor

### REMOVAL & INSTALLATION

1. Remove the windshield washer reservoir.

WARNING
Before repairing any air suspension components, disconnect power to the system by turning off the air suspension switch located in the passenger side kick panel area to prevent vehicle damage or personal injury.

2. Turn the air suspension switch to the OFF position.
3. Disconnect the air line tube to the air compressor drier by depressing the red ring. Remove the air line.
4. Detach the air compressor electrical connector.
5. Remove the air compressor bracket bolts.
6. Remove the air compressor.

To install:

When installing the air lines make sure the white air line is fully inserted into the fitting for correct installation.

7. The installation is the reverse of the removal.

## Air Compressor Drier

### REMOVAL & INSTALLATION

1. Disconnect the negative battery cable.
2. Remove the air compressor. Refer to the procedure in this section.
3. Remove the air compressor drier retaining screw and rotate 90° to unlock then remove the air compressor drier.

To install:

Inspect the O-ring for damage and replace as necessary. Lubricate the solenoid seal area with Silicone Brake Caliper Grease and Dielectric Compound D7AZ-19A331A or equivalent meeting Ford specification ESE-M1C171-A.

When installing the air lines, make sure the white air line is fully inserted into the fitting for correct installation.

Ride height adjustments must be performed after the air compressor/drier is installed.

4. The installation is the reverse of the removal.

## Control Module

### REMOVAL & INSTALLATION

1. Disconnect the negative battery cable.
2. Remove the instrument cluster panel. Refer to Section 6.
3. Remove the front control module mounting bracket screw.
4. Remove the rear control module mounting bracket screw.
5. Lift the control module and mounting bracket from the instrument panel and detach the control module electrical connectors.
6. The installation is the reverse of the removal.

## Height Sensor

### REMOVAL & INSTALLATION

WARNING
The electrical power to the air suspension system must be shut off prior to hoisting, jacking or towing an air suspension vehicle. This can be accomplished by turning off the air suspension switch located in the passenger side kick panel area. Failure to do so may result in unexpected inflation or deflation of the air springs which may result in shifting of the vehicle during these operations.

1. Raise and support the vehicle.
2. Detach the air suspension height sensor electrical connector.
3. Depress the metal retaining tabs and remove the air suspension height sensor.
4. The installation is the reverse of the removal.

## Air Spring

### PRECAUTIONS

- The electrical power to the air suspension system must be shut off prior to hoisting, jacking or towing an air suspension vehicle. This can be accomplished by turning off the air suspension switch located in the PASSENGER SIDE kick panel area. Failure to do so may result in unexpected inflation or deflation of the air springs which may result in shifting of the vehicle during these operations.
- Do not attempt to install or inflate any air spring that has become unfolded to prevent vehicle damage or personal injury.
- Do not attempt to inflate any air spring which has collapsed while deflated from the rebound hanging position to the jounce stop.
- When installing a new air spring, care must be taken to not apply a load to the suspension until the air springs have been inflated using the air spring fill procedure.
- After inflating an air spring in the hanging position, it must be inspected for proper shape.
- Do not remove an air spring under any circumstances when there is pressure in the air spring. Do not remove any components supporting an air spring without either exhausting the air or providing support for the air spring to prevent vehicle damage or personal injury.

### REMOVAL AND INSTALLATION

The vehicle must be positioned on a suitable lifting device prior to deflating the air suspension system.

1. Access the air suspension diagnostic connector behind the PASSENGER SIDE cowl side trim panel.

New Generation STAR (NGS) Tester can be used to emulate Superstar II Tester.

2. Turn the air suspension switch to the ON position and the ignition to the key on engine off (KOEO) position. Use Super STAR II Tester plugged into the air suspension diagnostic connector to perform the function test. Set Super STAR II Tester to the EEC-IV/MCU mode; also set it to the FAST mode. Press Super STAR II Tester button to the TEST position; DTC 10 will be displayed. Within two minutes, DTC 12 or 13 will be displayed. After DTC 12 or 13 is displayed, release the Super STAR II Tester button from the HOLD position. Wait at least 20 seconds and then press the Super STAR II Tester button to the TEST position. Within 10 seconds, the following DTCs will be displayed in order:

- 23 Vent Right Rear Air Spring
- 24 Vent Left Rear Air Spring
- 25 Vent Both Rear Air Springs
- 26 Compress Right Rear Air Spring
- 27 Compress Left Rear Air Spring
- 28 Compress Both Rear Air Springs
- 31 Cycle Compressor On and Off
- 32 Cycle Vent Solenoid Valve Open and Closed
- 33 Cycle Spring Solenoid Valves Open and Closed

3. Disconnect Super STAR II Tester after deflation is completed.
4. Within four seconds after DTC 23, 24 or 25 is displayed, depending on which air spring is to be deflated, release the Super STAR II Tester to the HOLD position. After deflation, turn the ignition to the OFF position.
5. Remove the wheel and tire assembly.
6. Remove the air line from the solenoid valve by depressing the red plastic retaining ring and pull the air line out of the solenoid.
7. Detach the solenoid valve electrical connector and position it aside.
8. Remove the retaining clip from the top of the air spring.
9. Compress the deflated air spring and remove it from the vehicle.

To install:

WARNING
Any air spring which is unfolded must be refolded prior to being installed in a vehicle.

10. Position the air spring into place and install the retaining clip at the top of the air spring.
11. Seat bottom of the air spring on the rear axle.
12. Connect the solenoid valve electrical connector.

When installing the air lines make sure the white air line is fully inserted into the fitting for correct installation.

13. Connect the air line into the solenoid valve line fitting.
14. Install the rear wheel and tire assembly.
15. Turn the air suspension switch to the ON position.

Inflation will start after 45 seconds.

16. Turn the ignition to the key on engine off (KOEO) position until the air springs are inflated to trim height.
17. Visually inspect each air spring to make sure the correct profile has been obtained. There should be no evidence of buckling or folding of the air springs.

## Solenoid Valve—Functional

### REMOVAL & INSTALLATION

1. Remove the air spring. Refer to the procedure in this section.

WARNING
Remove any dirt or other debris from the air spring prior to removing the solenoid valve from the air spring.

2. Remove the metal retaining clip from the solenoid valve.
3. Inspect the solenoid O-rings and replace as necessary.
4. Twist the solenoid valve and remove.

Be sure the new air spring solenoid is fully seated into both stages of the air spring. Lightly apply Silicone Brake Caliper Grease and Dielectric Compound D7AZ-19A331-A or equivalent meeting Ford specification ESE-M1C171-A to the O-rings. When installing the air lines, make sure the white air line is fully inserted into the fitting for correct installation.

5. The installation is the reverse of the removal.

## Solenoid Valve—Non-Functional

### REMOVAL & INSTALLATION

WARNING
Do not remove an air spring under any circumstances when there is pressure in the air spring. Do not remove any components supporting an air spring without either exhausting the air or providing support for the air spring to prevent vehicle damage or personal injury.

1. Raise and support the vehicle.
2. Remove the air line from the solenoid valve by depressing the red plastic retaining ring and pull the air line out of the solenoid.
3. Detach the solenoid valve electrical connector.

WARNING
Remove any dirt or other debris from the air spring prior to removing the solenoid valve from the air spring.

4. Remove the solenoid valve clip.
5. Hold the solenoid body from the side and rotate the solenoid valve out of the air spring to the first detent to release the air from the assembly.
6. Remove the retaining clip from the top of the air spring.
7. Compress the deflated air spring and remove it from the vehicle.
8. Remove the solenoid valve.

Be sure the new air spring solenoid is fully seated into both stages of the air spring. Check the solenoid valve O-rings for abrasion or cuts. Replace O-rings as required using air spring connector repair kit. Lightly apply Silicone Brake Caliper Grease and Dielectric Compound D7AZ-19A331-A or equivalent meeting Ford specification ESE-M1C171-A to the O-rings.

9. The installation is the reverse of the removal.

## Air Shocks

### REMOVAL & INSTALLATION

WARNING
The vehicle must be positioned on a suitable lifting device prior to deflating the air suspension system.

1. Deflate the air suspension system
2. Raise and support the vehicle.
3. On driver's side air shock removal only, disconnect the top of the front height sensor from the upper frame bracket.
4. Remove the air shock lower nut and bolt.
5. Disconnect the air spring solenoid air line by compressing the quick connect locking ring and pulling out the air line.
6. Remove the air shock upper nut, grommet, and the air shock.
7. The installation is the reverse of the removal.