York 210R OBA (On Board Air)

The order of things I wanted to do for my Jeep was beginning with functional/preventative. I started with some armor, and On Board Air was close to follow. I would rather have things I could use all the time and help me make it home, than get things like lockers and ground clearance that would just get my TJ into trouble!


From my auxillary fuse block, I have a +12V fused source go to the Viair pressure switch. The switch has a built in relay, so that’s the same +12V that goes to the serpentine clutch on the York. The switch has connectors for ground, and positive switched source. I mis-interpreted that as needing a positive switched source. It actually GIVES a positive source, and you switch to ground to enable the device. This caused me a little bit of trouble before I had to pull out the trusty multi-meter. The bad part is that I wanted this ignition controlled as well. I needed an ignition switched ground. I wired up a 2-relay gismo (one for switched positive, and one for switched ground) that I installed to solve this problem. Now, under my dash I have a clean switched ground and positive. I don’t have a use for the switched positive yet, but it’s nice to already have it so I don’t piggyback the accessory outlet with anything other than these relays!

OBA Switch Pressure Switch diagram Pressure Switch


My tank is mounted below the Jeep, between the frame rails. It’s opposite the muffler. I’ve seen a few write-ups with people mounting it there, and there’s plenty of room! Fit like a charm!

OBA Tank


Preparation – Tapped the rotolock fittings to 1/4″ NPT. The size of the tap is still larger than the 3/8″ NPT hose fittings, so I’m not worried about size and air-flow. Here’s a couple pictures of the fittings, and them tapped.

Standard York Rotolock Adapters Rotolock tapped! Final Rotolock Adapter!

Here’s the york mounted:

Nice Overhead Shot of completed OBA! Looking at the York from above!


My manifold has 2-3/8″ NPT ports (3 really, but 1 is plugged), and 5-1/4″ NPT ports. The two 3/8″ ports come from the york, and go to the tank. The 5 1/4″ ports are as follows:

  • Safety blow-off valve
  • Pressure Gauge
  • Hose to in-cab pressure gauge
  • Hose to pressure switch
  • Plugged (in the future, to another connector in case the tank blows)

Kilby Manifold Kilby Manifold (Diagram) In-Cab Pressure Gauge


My hoses (to and from tank, and everything else) run along the inside of the driver’s side frame-rail along with the brake lines as seen here!

Hoses/Coalescing Filter Hose routing! Hoses from the back

Quick-Connect Connectors:

I have two 1/4″ NPT Industrial quick-connectors. One on the front, and one on the rear.

Front Connector Rear Connector

Overall Schematic:

OBA Shematic


  • York 210R
  • Kilby Mounting Plate (K-1550, for ’97 4.0L I6 without a/c)
  • Serpentine Clutch
  • Longer Serpentine Belt (Gates Part #K060935)
  • Intake Filter (1/2″ NPT Male)
  • Coalescing Filter (2-3/8″ NPT Female Ports)
  • Check Valve (3/8″ NPT Female to 3/8″ NPT Male)
  • Manifold (2-3/8″ NPT Ports 5-1/4″ NPT Ports)
  • Safety Valve (1/4″ NPT Male)
  • Gauge (x2) (1-1/8″ NPT Male, 1-1/4″ NPT Male)
  • Pressure Switch (1/8″ NPT Male)
  • In-cab Switch (4x4mods.com part number: RS41P-10 Air)
  • Shut-off Valve (Husky, 2-3/8″ NPT Female Ports)
  • Quick Connects (x3)
  • 1/4″ NPT Male Threaded to 3/8″ Hose barb (x7)
  • 1/8″ NPT Female Threaded to 3/8″ Hose Barb (x2)
  • 3/8″ NPT Male Threaded to 3/8″ Hose Barb (x6)
  • 1/4″ NPT Male Threaded to 1/2″ NPT Male Threaded
  • 1/2″ NPT Coupler (Comes With Kilby’s Intake Filter)