York AC Compressor
Its a well known fact in the offroad community that an aired
down tire will have better traction offroad than a fully
inflated tire. It's common practice by those who know
this to air down their tires into the teens or even the single
digits just before hitting the trail so they might get the
best traction possible and to smooth out those teeth rattling
bumps. Airing down is easy. You just let the air out.
The problem is getting air back into the tires after your day
is done because if you're like most people, you have to drive
your rig home and proper air pressure is critical for safe
There are several ways to get the air back
into your tires.
Hit a gas station on your way home and pay 50
cent for about 3 minutes of use, then proceed to dump a few
bucks. That is if you can even
find a station let along one that has an air pump these days.
Carry one of those mini compressors
that power off your cigarette lighter port. They
works but the piston is so small in these units that airing up a
35" mud terrain to 30 PSI is like waiting for paint to dry.
For years this was my method in my other 4x4s. Besides the
time it takes to pump up, the compressor always got hot and I'd
always wonder if it was going to make it. But it was
better than nothing.
Carry some sort of pre-filled onboard air tank that you'll
pre-fill before the trip and empty into your tires after
wheeling. Just make sure you have enough reserve to fill
all your tires. These can be anything from a tank of
compressed air from your own compressor to a compressed C0²
high pressure tank. Whatever option you used, it will
eventually run out and probably at the moment you need it most.
Higher quality electric compressors can
be purchased which can be mounted inside your rig. People who
have ARB's air lockers will typically have a compressor for the
air lockers. These are better than the typical mini electric
compressors with a higher CFM but most of them will still take
almost 10 minutes to air up a single tire and will cost at least
$250 after all is complete.
Convert an engine mounted AC compressor to
pump air rather than the Freon and mount an auxiliary tank
somewhere on the vehicle. The most common compressor to
convert is the York compressor (currently owned by Climate Control
Inc. "York" was the previous manufacturer). The
York doesn't rely of the Freon
to oil the system because it has its own oil reservoir making it
idea for this type of conversion. This article deals with
assembling an air system around a York compressor.
Here are some advantages to using this type of air system:
Cost - If you search junk yards, ebay,
used parts dealers, these compressors can typically be found for less
than 50 bucks. The most common vehicle the larges York
is found on is Volvos manufactured from
Available Parts - You can obtain
parts to convert the AC compressor's fittings to NPT fittings, which
allows you to use common, inexpressive NPT air system
CFM - The larger compressors have a
high CFM allowing you to pump up your tires in a matter of
Power - Since these compressors are
engine mounted and drive off your engines crank, they are
powerful and will pump air just as efficiently at higher
pressures while bringing your reserve tank up to the max
Reliability - The AC compressors
are built to last, at least as long as the vehicle is in
service. As an air compressor, they will continue to
provide years of service as long as they are properly maintained.
Versatility - With an auxiliary tank,
you'll have enough air reserve run air tools and the
larger York compressors will actually keep up with the CFM
demand of most air tools. You might even use your air
reserve for other things like a backup to your ARB
compressor or an old air horn off of a Kenworth 18 wheeler,
The Cool Mod Factor - With a complete
onboard air system in your rig, you can chalk up a few points
for a cool modification that almost ranks up with the
onboard welding system. You'll not only fill your
tires quickly but also help out your wheeling friends air
theirs up too as you show off your onboard air system.
Planning the York
While building up my 1978 Jeep CJ-7 I decided to take advantage
of the 210 York AC compressor I acquired on the AMC 360 and convert it to pump air.
As it turned out I had the
largest of the York compressors, the model 210, which was a big plus. I also
had the advantage of having all the factory brackets that bolted the
to my engine so I didn't have to figure out how to mount
it. I understand that most people will be looking for a
compressor and brackets to mount their compressor to their
engine. To help with the search for compressors and mounting
options please see the York Identification page and the Installation
page for more info on other applications.
For this project my focus was on a few things. First I had to
convert the pump's Freon fittings to air fittings. At first I
was searching through the bins at my local Ace Hardware store,
looking for the right threaded fittings to convert what I had to an
NPT barbed air hose fitting. I was getting close to finding what I
needed to adapt the freon fitting to NPT but not quite.
Then a friend in the know told me about Kilby Enterprises and their
selection of specific parts to make the job easier. So I took into
account what I had and drew up a parts list of what I needed to
convert my York to an air compressor and place an order.
Parts List - Acquiring
The first thing I had to do was determine what the
system would look like and what parts were necessary to successfully
pump air, regulate the pressure, route the air lines through the
vehicle and store the air. I had enough foresight while
building my bumpers to create bumpers that doubled as air tanks so
storing the air was a done deal. To read more about the custom
bumpers / tire rack project, click
Pumping the air (converting the York), routing and
regulating the pressure was what I had to figure out. I looked
at a few diagrams I found online to learn that that system needed a
few key components. Air entering the York had to first be
clean so an intake filter is required. Air exiting the York
pump had to be cleared of oil that comes from the York using a
Coalescing Filter, better known as an oil / moisture trap.
Note: Apparently the amount of oil can be reduced with
modification. I'll explain that later.
Next in line, a check valve to stop air leaking back
into the York. From there you're on the pressure side of
stored air. I used an air manifold to branch out to other
components, which I could clamp down and mount some where.
Here you'll regulate the pressure with a pressure switch, which will
provide or not provide power to your pumps magnetic clutch depending
on the pressure in your system. (power to the pressure switch
will first go through a fuse block, then a power switch to turn it
off when not in use). Beyond that its accessories like the
tank, gauges, lines to outlets, a relief valve, etc. Below is
a breakdown of what I had and needed including a diagram of my
Components I had:
York AC Compressor
- I had acquired the York 210 series when I bought my engine.
The 210 compressor is a 2 cylinder, 10.3 cu. in.
displacement with 4 CFM at 90 psi while running at 1200
rpm. See the York Identification page for more info.
- Needed to mount the York compressor to the engine. Not a
problem for me, I had the factory brackets already on my AMC
360. If you have an AMC 304, 360 or 401, look around for
the factory brackets. AMC used the York in their Full Size
Jeeps (Wagoneers, Grand Cherokees, J Trucks). If you have
another engine, check out Kilby Enterprises. If still no
luck you may have to fabricate something.
Air Tanks -
When I designed my custom
bumper project, it included creating a
front and rear bumper that doubled as air tanks with a combined
volume of 2.5 gallons. Auxiliary air tanks can be
purchased in a variety of sizes. Kilby Enterprises sells a
few low profile tanks that can be mounted in an inconspicuous
place on your vehicle.
- While an air manifold may not be necessary, it does help
branch off air lines and components. They are cheap, can
be found almost anywhere NPT fittings are sold and help keep the
layout clean and organized under the hood. I used mine to
not only organize the components but also made up some simple
clamps that hung it from my grill brace on the passenger
side. More on that on the installation page.
Oil / moisture trap (Coalescing Filter)
- A necessity with the York. This will capture the oil
that will blow out the outlet valve.
- Its nice to know what your current pressure is. I chose
to mount two air gauges, one under the hood and one in the cab.
- Various easy to find NPT / Pneumatic connectors
and fittings. In my system I used mostly 1/4" NPT
parts. These include elbows, T's, couplers, reducers, male
to male or female to female connectors where necessary,
1/4" and 3/8" barbed hose fittings to NPT 1/4"
and 3/8" fittings (male and female). Again see the
diagram, which will explain a lot. What I didn't have I
picked up at a local hardware store.
About a 25 foot length of 1/4" pneumatic
air hose to connect the front and rear tank (bumpers) to the air
manifold. The hose had male NPT ends. I cut the hose
in halves and routed each half to the front and rear bumper.
Components I needed:
Tube-O fitting to 1/2" NPT
- These are used to convert the York's inlet and outlet to the
standard 1/2" NPT air fittings. (Kilby's Rotolock fittings)
Square D pressure
Switch (or various other name brands) - A necessity
to automatically disengage the York pump from your crank when
the desired air pressure is reached.
- You don't want to suck dust, dirt and mud into your
Adjustable Relief Valve
- Just in case the pressure in your system reaches beyond the
maximum desired pressure for whatever reason (pressure switch
failure, York clutch seizure), the relief valve will blow,
allowing air to escape (and make a hell of a noise to let you
- When your York is not pumping air into the air system, you
need to prevent the air from seeping backwards into the
compressor. Check Valve will do just that.
||York AC Compressor (factory
installed on an AMC 360 out of a Jeep Grand Cherokee)
|| Tube-O fitting to 1/2" NPT
(Kilby's Rotolock fittings, )
|| 1/2" NPT female to female (kilby
or a hardware store)
||Air Intake Filter (Kilby Air
Intake Filter, FS-07-050)
||Square D pressure switch
(set to 120 psi off) (Kilby, 49J59)
||Air Manifold (hardware
||Adjustable Relief Valve (set
to blow at about 130 psi) (kilby, NC25)
||Pressure Gauges (on at manifold,
one on dash) (hardware store)
||Oil / moisture trap (Coalescing Filter)
||Check Valve (Kilby, CB38)
||1/4" T, 3 female ports
||1/4" Couplers, male
port (hardware store)
||Barbed 1/4" to
1/4" male port (hardware store)
|| 1/2" NPT male to 1/4"
barbed hose fitting (hardware store)
||1/4" male to 3/8"
(the Oil / moisture trap is actually a 3/8" so the
fitting on both sides of the moisture trap is a
1/4" male to 3/8" male. (hardware store)
||1/4" Elbow, male one
side, female other side. (hardware store)
||Male to Male connector
||1/4" Elbow, male one
side, female other side. (hardware store)
||1/4" NPT to 3/8"
Nylon Quick Connect (Grainger) NOTE: The air horn and
pressure gauges use different sizes, pressure gauges use
1/8" Nylon Quick Connect and Air horn fitting use
3/8" Nylon Quick Connect.
||1/4" male NPT to
1/8" female NPT (hardware store)
||3/8" Nylon Quick
Connect to 1/8" male NPT (air horn adaptor)
||Yard Sale acquisition -
Really loud air horn off a '76 Mack
||1/8" nylon air
hose (hardware store)
||Stock 1/4" air line
with male factory fittings (hardware store)
||Air Tanks, Custom
Front and Rear Bumper Project
||1/4" NPT male to male
||Air Blow Gun —
1/4" female Inlet, 1/4" threaded outlet.
||3/8" nylon air hose for
air horn (needed volume) (hardware store)