2003 Infiniti M45 Air Runner Air Suspension Install 4

If you follow the site you will know that we recently teamed up with the good people at Air Runner Suspensions to get my Project VIP Infiniti M45 sitting proper. After what seemed like the longest 4 weeks the Y34 Air Runner kit arrived fresh from the land of the rising sun. It took a few weeks to set up a location for us to do the install but everything came together last weekend.

Air System Information:

System Model: Infiniti M45 2WD/ 2003-2004(Y34)
Part Number: #2986
MSRP: $4,293 USD
Estimated Install: $1500 – $1600

Kit Contents:

  • 2 Front Sleeved 4-Dial Struts
  • 2 Rear Bellowed 4-Dial Bags
  • 2 Rear KYB Shocks
  • 1 Tank (Standard or Pancake)
  • 1 Heavy Duty Compressor
  • 1 Mounting Plate
  • 1 Pressure Switch

More Information on Air Runner Y34 Air Suspension

My first impression was the kit is fantastic and such a solid looking setup. The best word to describe it was “beefy”. Everyone that saw the parts was thoroughly impressed. The install was taken care of by Doug of East Coast Garage and the boys at Audio Revolution. We will be doing a feature on their audio shop here in the next few weeks and really appreciate the help with the install and the use of their facility.

On to the instructions for the install. I tried to be as detailed as possible and focused on things specific to the 03 Infiniti M45. I did not redo the basic instructions on how to wire and plumb the system as it is well explained in the instructions from Air Runner.

The gallery documents the instructions with coordinating pictures. It would have made the post way to long to put pictures with the instructions. I did put some important pictures for specific parts of the install.

Full Gallery of pictures on Jade’s Flickr Page.

Things you will need:

  • Air Impact Gun
  • Air Impact Wrench
  • Air Cut Off Wheel
  • Air Grinder
  • 6 Good Jack Stands
  • Various Sockets
  • Stubby 14mm ratchet wrench
  • Welder (optional)
  • 5/16 self tapping screw
  • Floor jack
  • 32mm socket to remove hub

Front Assembly:

  • Jack up car and put it on jack stands.
  • Remove wheels.
  • Remove brake caliper and brake line clip.
  • Let caliper hang on frame.
  • Remove brake pads.
  • Remove caliper bracket.
  • Undo upper sway bar link and lay of frame (17mm).
  • Remove abs sensor cut ziptie.
  • Remove 2 clips that hold abs sensor on the strut and let it hang on the frame.
  • Remove cotter pin from the tie rod.
  • Remove tie rod nut by hitting it with a hammer. Take note not to hit the tie rod with the hammer.  It will drop when its ready to go.
  • Remove the caliper.
  • Remove the lower ball join nut (22mm).
  • Slide strut all the way out.
  • Using a pry bar push lower control arm down.
  • Separate ball joint from lower control arm.
  • Remove 3 upper nuts that holds strut in.
  • Remove the strut.
  • Remove dust cap from OEM strut assembly.
  • Install air runner strut assembly in the place of the OEM one, make sure the arrow on the top of the air runner strut assembly faces the firewall.
  • Secure with upper strut nuts and tighten.
  • Re insert the lower ball joint, yes there should be a gap.
  • Tighten ball joint nut, install cotter pin.
  • Reinstall upper sway bar arm and tighten.
  • Repeat process on opposite side.
  • Transfer over the brake shield and hub from the stock unit to the air runner unit.
  • You need a 32mm socket to get the hub off.

Rear Assembly:

  • Take floor jack and place it under the lower control arm and raise it to take the pressure off the lower control arm.
  • Remove lower control arm bolt.
  • Remove lower shock bolt (17mm).
  • Let the jack down and the spring will extend.
  • Remove the jack and by hand push the lower control arm and remove the spring.
  • Remove 17mm bolt holding rear lower control arm.
  • Remove the rear lower control arm.
  • Re install the air runner lower control arm.
  • Remove the rubber spring mount.
  • Remove the 12 mm bolt holding the metal spring cup on upper sway perch.


The instructions call for you to weld the upper bag mount to the frame. Since there is only one bolt holding the mount in it could possibly spin. The weld is not to secure the mount just to keep it from spinning. In the air runner instructions they have you bolt the bag to the mount then mount the unit to the frame. Then weld it in place. The reason they tell you to weld is because if bolt the bag to the mount before installing the mount it there would be no way to access the second hole to put the self tapping screw through. Also accessing the bolts that attach the bag to the mount is very hard, unless you have a 14mm ratcheting wrench. With out that tool this method would be nearly impossible.

We decided to do this without welding but with a 5/16 self tapping screw place through the second hole in the air runner upper bag mount.

  • Hold the upper bag mount to the frame in the correct position
  • Mark and pre drill hole for self tapping screw (mark with sharpee)
  • Bolt the upper bag mount to the frame using the supplied bolt
  • Screw self tapping 5/16th into hole you re drilled
  • Install air fitting on rear bag
  • Install bag into upper cup and tighten the hard to reach bolts using a 14mm stubby ratcheting wrench.
  • Bolt lower control arm in using oem bolt.
  • Cut off 18ft of the red air line.
  • Run air line over the rear subframe.
  • Using a floor jack raise the lower control arm to align the bolt holes.
  • Tighten rear control arm front outer bolt.
  • Repeat on opposite side.
  • Make sure to support lower control arm and do not let the bag hang. Do this with floor jacks if you have them.
  • We used cut 2×4’s since we didn’t have extra jack stands.
  • Remove everything in the trunk.
  • Remove the back seats, there are 2 rings on the outer edges of the seats.
  • Remove the exposed 10mm bolts on each side.
  • Flip down armrest and pull cover back.
  • Remove the 10mm bolts behind the armrest.
  • Unsnap the rear top deck to access the top shock mounts.
  • Remove the brake light in the top deck.
  • Remove the seal around the door trim to access clips on panels and remove the side panels..
  • The top deck slips out and slides forward allowing access to rear strut mounts
  • Remove bolts holding shock in and remove shock.
  • Transfer the upper strut mount to the KYB unit that came with the air runner kit.
  • Put KYB strut in place of the OEM unit.
  • Repeat on opposite side.

Uninstall the center console

  • Unscrew the shifter.
  • Remove the trim around the shifter.
  • Remove the trim around the cassette player.
  • Open the armrest and remove the cup holder.
  • Remove the exposed screws.
  • Now you can pull out the center console.
  • Undo the screws in the ashtray and remove the ashtray.
  • Remove the door sill cover on the driverside.
  • Now remove the inner panel on the same side.
  • Peel back the carpet to expose wiring.
  • Run the needed electrical wires from the front of the cab to the trunk.

Tank and compressor mounting

We chose to “float” the tank along the back wall so that you can still get to the spare tire if needed. Once all of the covers are removed from the trunk you will see the gas tank at the back of the trunk.

  • On the gas tank you will see two tabs that the rear panel attaches to the tank.
  • We used these two tabs to mount our tank to.
  • Run a long bolt through the back of the mounting tab and secure it with a nut.
  • We cut a 2 foot 2 x 4 and notched it across the top to allow the mounting plates lip to slide into. This is very similar to how you mount a floating shelf in your house.
  • Drill two holes into the wood in the place the bolts come through.
  • Counter sink the back of the wood to allow the 2×4 to sit flush.
  • Mount the tank and compressor to the supplied stainless mounting plate. Since we wanted the compressor centered we could not use the holes that were in the plate.
  • We attached the compressor using self tappers since the holes did not line up for the location we wanted.
  • We mounted the emergency fill valve on the right side of the plate so you can access it.


One suggestion I would make to air runner is that they don’t pre-drill any holes other than the tank, because that is centered and would never change. I think they do all the holes to accommodate multiple types of setups and components. This is nice from a manufacturing stand point but leaves holes in the plate if you have the basic system and it just doesn’t look good. A good drill, bits and self tappers allow you to attaching anything you want where ever you want.

  • Hook the tank and compressor up using the air runner supplied instructions.
  • There is a grommet and hole in the right side of the trunk that is perfect for getting the air lines into the trunk.
  • Remove the grommet and cut a star into the grommet to allow the lines to run through it.
  • Spray the cut grommet with some wd40 to allow the lines to run through easily.
  • Run the lies from the rear bags to the hole in the trunk.

Note the locations where we ran the lines in the photos. Make sure you don’t run any of the lines near anything that gets hot.

  • Run the lines along the right side of the trunk and secure using zip ties and wire mounts.
  • The Styrofoam that goes in the trunk needs to be notched out to allow the lines to not be crushed. Notch it according to the photos.
  • Run your air lines into the cab in right near the rear shock location.
  • Hook up the relay to the wiring you ran earlier.
  • Place everything back into the trunk.
  • Drill two holes in the back fabric panel to allow the lines and wires to go to the tank and compressor..
  • Once the back panel is back on run your lines and wires through your drilled holes and the bolts stick through the OEM holes in the center of the panel.
  • Paint the edges and center of the 2×4 black so if it shows you wont notice it.
  • Now slide the 2×4 to the exposed bolts.
  • Secure the board to the bolt using another 2 nuts.
  • Cut off the extra length of the bolts.
  • Take your assembled tank and compressor unit and place it in your trunk.
  • Hook the wires and air lines up.
  • Slide the tank and compressor assembly into the notched section of the board.
  • There are two small holes to the right and left of large center hole in the top of the tank. Put two screws through that to make sure the assembly does not move.
  • Cover the screws with black screw caps.
  • Secure your air line to the front right assembly.
  • Locate the area in the lower right foot well as shown in the picture to drill a hole in the firewall to get the lines into the cab.
  • Place a grommet in the hole you drilled.
  • Route the airline as shown in the picture and through the hole, secure with zip ties.
  • Secure your airline to the front left assembly and route over engine and to hole as shown in picture, secure with zip ties.
  • Route the lines from the back to the center console.
  • Hook up and wire the kit according to the air runner instructions.

Switch mounting

  • We decided to mount the switches inside the center armrest console.
  • The M45 armrest has two openings a top and bottom. We put the air lines and mounted the switch assembly in the bottom portion on the armrest by using the supplied bracket and mounted it at the front.
  • Cut a hole in the upper cover so that when you close the top section the switches show through.

Gauge mounting

  • The only place to really mount the gauges is in the ashtray location.
  • Cut two holes in the face of the ashtray to allow the gauges to mount.
  • Before you cut anything in the ashtray make some marks on the outer and inner frames. This is so you know how to put it back together.
  • Cut away and remove the center area to allow room for the gauges.
  • Due to cutting you the ashtray does not stay together.
  • Glue the ashtray back together but make sure you note the marks you made so that the ashtray is at the proper angle when installed.
  • We intend to redo the gauges with a custom panel but did not have time during the original install.
  • Hook the switches and gauges up per the supplied air runner instructions.
  • After the system is all in test all of your electrical and air fittings.
  • Check your fittings for air leaks using soapy water.
  • Put your wheels back on and take the car off the jack stands.

Fitment issues:

Due to the aggressive offsets on my wheels we had to make adjustments to the fenders. If you do not have such aggressive wheels you may not have to do this.

  • Trim or roll the rear fenders (I had already trimmed the rear fender lips when I installed my springs originally).
  • Remove the front fender inner liners and bend the mounting tabs in.
  • Trim or roll the front fenders.

Testing of the system

  • Take the car off the jack stands.
  • Test the system operation and check clearance issues.
  • Slowly lower the car as someone watches to see if your fenders are clearing the rims.

With the trimming and removal of the fender liner in the front we were able to put the car full down but the clearance was very tight.

Take the car for an alignment

Since we put in a whole new suspension everything was out of wack and the steering wheel was tilted when you drove.

You may have a hard time finding a shop to align your car since it is “modified”. I had to go to 3 places before I found the Tire Kingdom on Tuskawilla road in Oviedo. The service guy had a car that he had put an air suspension on and was knowledgeable on how to align a car with an air suspension.

We had to leave the rear toe slightly out for now until I can roll and pull the rear fenders a little. Unfortunately when we set the toe perfect it removes some camber and caused me not to be able to go full down. Once we roll and pull the front and rear fenders everything should be perfect. I am hoping to be able to roll lower than I am now when driving after the fender work.

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