2005 Chevy 2500HD Air Compressor - Diesel Power Magazine

Serious truck owners know having a supply of compressed air can be a lifesaver. You can pump up giant mud tires before getting on the freeway and have the ability to use air tools to fix all the parts you break on the trails. By mounting a compressor that is driven by the engine under the hood and a storage tank under the bed, you can always have pressurized air on tap. Kilby Enterprises is now offering a kit for your Cummins or Duramax truck that gives you all that, along with a power switch in the cab and quick-connect fittings for both ends of your truck.

This '05 Chevy 2500HD has already been modified for off-roading and long-haul towing. The Kilby onboard air kit comes with an air tank, a compressor, a power switch, an air manifold with pressure gauge, a coalescing filter to keep lubricating oil out of the air lines, quick-connect fittings for the front and rear of the truck, air lines, and brass fittings for all connections. The kit is designed to fit a stock truck, so a few modifications were needed for this 4x4 tow rig, such as a smaller air tank than the one here to fit in the space available next to an auxiliary fuel tank.
This '05 Chevy 2500HD has already been modified for off-roading and long-haul towing. The
1. Disconnect the negative battery terminals. Remove the serpentine belt from the engine by loosening the tensioner with a long wrench and a sleeve for maximum leverage. Don't be afraid to ask for help (it's better than explaining how you gave yourself a black eye with a wrench) because you'll need at least one buddy to assist with the install if you want it done in less than half a day.
1. Disconnect the negative battery terminals. Remove the serpentine belt from the engine b
2. Remove the driver-side bolts on the top of the air-conditioning compressor and temporarily mount the air-compressor bracket to check for clearances. This truck has an aftermarket engine programmer and supports a large stereo system that adds lots of wires and inline fuses to the engine bay, so many of the cables had to be rerouted.
2. Remove the driver-side bolts on the top of the air-conditioning compressor and temporar

3. Install the clutch assembly onto the compressor and mark the keyway on the clutch housing with some paint so you can tell when the wheel is in a position where the compressor oil can be checked.
3. Install the clutch assembly onto the compressor and mark the keyway on the clutch housi
4. Bolt the mounting bracket to the air compressor before installing it into the engine bay. This is one of the steps where you'll need a buddy so he can hold the compressor level while you bolt it in. This will ensure the vibration of the engine does not loosen it...
4. Bolt the mounting bracket to the air compressor before installing it into the engine ba
...The air compressor can be mounted horizontally or vertically. The vertical mounting did not leave enough clearance under the stock hood in this application.
...The air compressor can be mounted horizontally or vertically. The vertical mounting did

5. GM uses a six-rib serpentine belt but doesn't use one long enough for this application, so a Ford Power Stroke eight-rib belt is relieved of two ribs. Make sure to know which engine your truck has before you order this kit. In 2005 alone, there are four different stock belt lengths for the LLY Duramax...
5. GM uses a six-rib serpentine belt but doesn't use one long enough for this application,
...This version of the LLY (single alternator with A/C and vacuum pump) requires the installation of some smaller idler pulleys in the accessory drive so the belt will fit properly.
...This version of the LLY (single alternator with A/C and vacuum pump) requires the insta

6. Next, the air-outlet line is attached and routed to the coalescing oil filter (right) before heading to the manifold with the blow-off safety valve and pressure gauge (above). All fittings require the use of Teflon plumber's tape to keep connections airtight. For this Duramax engine bay, the fuse-box housing was removed before holes were tapped for the manifold mount to prevent damage to the electrical system.

7. After you install the air filter and the oil-return line is plumbed, you're ready to route the compressor clutch wire into the cabin and mount the activation switch.
7. After you install the air filter and the oil-return line is plumbed, you're ready to ro
8. You'll need to take some measurements before the mounting bracket for the air tank is installed. Route the tank and air lines away from hot exhaust components or moving suspension and driveline parts...
8. You'll need to take some measurements before the mounting bracket for the air tank is i
...For this truck, a smaller air tank had to be ordered because an auxilary fuel tank had been added under the bed. To keep the air lines protected when this truck is jumping in the desert, the hoses were mounted inside the framerails.
...For this truck, a smaller air tank had to be ordered because an auxilary fuel tank had

9. Quick-connect fittings can now be mounted at the front and rear of the truck. Holes were drilled, the rear fitting was tucked under the bumper, and the front was mounted on the radiator support behind the winch where it's accessible but still protected by the bumper. The Kilby Enterprises kit comes with brackets designed to match stock bumper-mounting locations, but the quick-connect fittings can easily be mounted elsewhere. Rubber caps prevent sand, water, and mud from getting into the fittings.
9. Quick-connect fittings can now be mounted at the front and rear of the truck. Holes wer
10. Check every single connection is checked with a spray of soapy water to reveal air leaks. Skimping on this step can lead to slow leaks that will plague your system in the future. Even this professional installation had a couple of leaky connections that needed some new Teflon tape.
10. Check every single connection is checked with a spray of soapy water to reveal air lea
With the kit installed, all you need is an air line so you can clip it to the onboard air system and start filling large tires quickly and powering your collection of air tools.
With the kit installed, all you need is an air line so you can clip it to the onboard air