Installation Manual for Pacbrake 10355-X Air Suspension Kit

Important Information

This air suspension kit is designed for Chevy/GMC 2500/3500 trucks. It is critical to note that this kit does not increase the vehicle's Gross Vehicle Weight Rating (GVWR). Always adhere to the manufacturer's maximum capacity limits. Ensure there is sufficient clearance between the air bag and surrounding components to prevent contact during inflation or compression. Use only the provided nylon hose cutter or a sharp utility knife to cut air lines; using scissors or wire cutters will distort the line and cause leaks.

Kit Contents and Tools

Before beginning, verify all parts are present, including the Extreme Duty Air Bags, brackets, U-bolts, and hardware. Required tools include a hoist or floor jack, safety stands, torque wrench, standard combination wrenches, ratchet, metric and standard sockets, hose cutter, pipe thread sealant, and a spray bottle with dish soap and water for leak testing.

Installation Steps

1. Measure Stock Ride Height: Park on a level surface and measure the distance between the wheel hub center and the fender well.
2. Remove Rear Wheels: Secure the vehicle with wheel chocks and jack stands under the rear axle.
3. Remove Jounce Bumper: Pry the jounce bumper assembly out of the retaining cup.
4. Remove ABS/Brake Brackets: Unclip the ABS wiring loom and remove the M8 bolt holding the bracket to the strike plate.
5. Assemble Air Springs: Attach the roll plate and lower bracket to the air spring using countersunk cap screws (torque to 20 ft-lbs). Install the swivel fitting with thread sealant.
6. Install Assemblies: Position the air spring assembly on the jounce bumper strike plate.
7. Install ABS Relocation Bracket: Secure the relocation bracket to the lower bracket using carriage bolts and flange nuts.
8. Install Axle Clamp Bar: Align the axle strap with the carriage bolts and secure with flat washers and nylon locknuts. Torque axle strap nuts and relocation bracket nuts to 20 ft-lbs.
9. Secure Upper Bracket: Install square and round U-bolts around the frame and jounce bumper cup. Torque all U-bolt nuts to 20 ft-lbs.
10. Attach Brake/E-Brake Line Bracket: Reattach the bracket removed in step 4 using the M8 bolt (torque to 19 ft-lbs).
11. Install Heat Shield: Attach the heat shield to the exhaust pipe using ring clamps, ensuring 1/2 inch of dead space.
12. Install Air Line: Cut the air line into two equal lengths. Route lines to the air springs and fill valves, ensuring they are secured away from heat and moving parts.

Post-Installation and Maintenance

After installation, inflate both air springs to 90 psi and check all connections for leaks using a dish soap and water mixture. Large bubbles indicate a leak. Re-torque all fasteners after the first 500 miles of driving. Never operate the vehicle with less than 10 psi or more than 100 psi in the air springs. Always maintain at least 10 psi to avoid voiding the warranty.