WIRELESS GMC AIR SYSTEM
WHAT IS WIRELESS AIR,
YOU ARE ALREADY THERE IF:
* you are running with your bags on a shut-off
, (pix stolen from
* you use schrader valves to fill your air bags
* no need to discuss if this works --- you are already there !
YOU ARE GOING TOWARD WIRELESS AIR
IF THIS IS YOU:
Your coach leaks down - all the time
* Need to rebuild / replace your air pump
* Need to replace the air hoses
* Valves running to the front -
all over the GMC?
* Tired of not being able to
level your coach ?
* Have 2 air pumps to replace?
* No longer care if you
are Power Level, EL I , or EL II system
* Remove all the air lines
- except one to each air bag system
* No leveling valves
* No running valves,
* Only one air pump, (
back by the bags)
INFORMATION ON WIRELESS AIR (12.22.11)
Here is a link to a pic of my
wireless air system test bench and latest wireless air system that I
In the pic you will see
the system is setting on a test bench that I also built so I can
determine that the wireless air system is leak free and that the
digital remote controller is functioning properly. I use the test bench to test each wireless
air system to be sure the air system is leak free and that all the
electronics are functioning properly
I found it to be fairly expensive to
have the aluminum frame built like my original one. After doing
some looking around I remembered seeing pictures of what Ray Erspamer
air setup when he redid his air system some time ago. I contacted him
and he said he used UHMW plastic material and it has held up great.
So I ordered some and built the frame using it instead of
aluminum. Works great. Easy to work with. You can cut it
with a table saw. Drills easily. That solves a problem for
someone trying to figure out what to use to build a frame. It
looks great when you are done.
1 The wireless kit in the pic is
different than the one I installed on my coach 15 months ago.
Same part number, but new an improved.
The digital remote has a number of icons that mine does not have such
as low battery, leak detected, fail indicator for valve blockage or
communication failure and more.
2 The two(2) connections on the
digital manifold are the easy slip in style instead of the old style
connector that you had to use a wrench to tighten like mine.
3 The new wireless air system comes
with the digital remote mated with the digital manifold. No more
having to tough the two together on setup to try and get them to
recognize each other.
4 There are now only two (2) wire to
hook-up to the coach with this setup as compared to three (3) my old
one. One wire goes to ground and the other to the ignition
Those are the main difference.
Not a lot, but a few.
IS AN EXCELLENT PRESENTATION OF "WHAT IT IS"
JOHN SHOTWELL AND BYRON SONGER (GMCES)
There are lots, and lots of GMCs that do not have working air-leveling
systems, and have to run on schrader valves, and shutoffs (at the
risk of death due to exploding air bags;>).
the wireless air
system used by Shotwell, and Bovee, allow you to remove all of the OEM air system, and
simply connect a single hose to each bag, and adjust the height
of your GMC
This system has been presented on GMC coaches on bothe coasts.
this system is very easy to install and use, and will keep you from
sticking your head in beside the explosive air bags, and
shutoff valves. . geneF
The system is designed as an automatic leveling system. If it
senses air pressure gain or loss of more than 3 pounds difference than
the setting you have programed into the wireless digital
remote controller for each bag, it will automatically readjusts the air
pressure in each bag back to the programed setting when the ignition
key is turned on.
This particular system was not designed to be used with leveling
control valves. Gary Bovee
have a late '78 Royale Center Kitchen with the EL II system. The air lines had been
butchered by some PO, and one of the leveling sensor links was missing.
there were two airlines in the driver’s side wheel well that were not
to anything. Only one of the two compressors worked (sorta). We, like a
GMC owners, always used Schrader valves and shutoffs to pump up the air
recently redid the complete rear braking system, and while back there,
it was a good time to get the EL II system working.
I had four
extra junk yard compressors that were in a box that came with the
of them worked very well, and one got real hot and smelled
‘electrical’. So out
of the total of six pumps I had to work with, none were very good.
one of the two optical height sensors actually worked. The bad one
off a compressor at all. I also found that one of the 1/4" air lines
traverses the body had a flat spot in it, just like when you put a
penny on the
railroad track to flatten it. Probably happened when all but four of
body-to-frame isolator pads fell out over the years. Those pads have
decision time. Do we keep beating a 32 year old dead horse, or look at
alternatives to get this coach pumped up to where it should be. I
the net and found a couple of interesting items. One was a system for
(?) that used magnets and magnetic sensors on the frame - you put
heavy in the bed, and the little compressor pumps up the air springs
bags) to bring it level again. Great! But the system fed both sides
the vehicle at the same time - not good for our coaches, because we may
have different pressures in each air bag.
found what we ended up getting and installing. A system that would put
pressures in each air bag, and control those pressures automatically.
But it lacked
the automatic leveling feature, as the above system had. Figuring that
more important to be able to air up each bag by itself, this system
better for our coach.
AirLift 72000 Wireless Leveling Control System
system consists of one small compressor, a 'module', a relay, 25' of
DOT tubing, wiring harnesses, and all the hardware you could want. It
to a 12v, on-all-the-time lead, a 12v, ignition switched lead, and a
You run an air line from the compressor to the module, and two air
the module, one to each of the air bags. That’s it. Simple.
part is that it includes a remote control, about the size of a garage
opener, that controls the whole system - even from outside the coach.
control the pressure in each bag individually and set the pressures up
psi in each bag. It has a dump feature to let the air out of the bags.
you put in 40 gallons of water, and now your right side is down an
the remote and increase the pressure in the right air bag to bring the
to correct ride height. Again, simple.
I cut a 1
x 1 to the correct length to fit right under the front zerk on the
bogies. I can
stand outside the coach with the remote in hand and adjust the air
the stick just fits under the zerk. I made the stick length based on
correct ride height for the rear by the holes in the frame. The remote
two 'preset' buttons - I keep the pressures in the 1st button for road
and the 2nd button for the current campsite we’re in. When
the campground, we hit the #1 button and we get right up to the correct
for the road. Still simple.
going into somewhere that might cause the coach to scrape its rear end,
hit the ‘up’ arrow and the compressor will pump both bags up 10 lbs
it again, and they both go up another 10#. Also, there’s a ‘down’ arrow
will dump 10 lbs from both bags each time you hit it.
system will increase or decrease the pressure in each bag automatically
you have each bag pressure set to, whenever the key is on. Also, the
control will not let either bag go above 100#.
coach is a center kitchen, the two old compressors were in a cabinet in
rear section, behind the bath. I just replaced both of those with a new
275C that I had on hand. The compressor that comes with the new system
Viair) puts out a little over 1.0 cfm, and the 275C puts out 2.03 cfm.
I used the
275C because I had it. I have no doubt that the included compressor
keeping the bags pumped up; it was designed for the system (unless you
susbstantial leak, at which point you should tackle that problem first,
anyway). Also, as the EL II original setup didn’t use an air tank, we
the install, the remote control has to be ‘joined’ to the module.
keep your campground neighbor from messin’ with your pressures in the
the night with his remote. Your remote will only control your system. I
some of the old wiring from the original EL II system, as it was
from the original pumps.
might not be for everyone, or if you're trying to stay authentic, but
Bob Burkitt was kind enough to point
me in the direction to contact John Shotwell who had installed the Air
Lift #72000 system.
I got info from John and then modified the system to my liking.
I have been trying for sometime to
figure out what to do with my original air system on my 1978 Royale
that the PO had modified trying to upgrade it from and EL-1 to an EL-II
system. When I got the coach all the wires going to the compressor and
wires from the height control valve had been cut off by the compressor.
Since I am an electrically challenged one I new I had a real mess on my
hands. But, thanks to those of you who responded to my air system
questions a couple of months ago I found a solution that works for me.
Particularly, big thanks to Bob Burkitt and John Shotwell for their
What I ended up doing is installing a wireless
air system. All I needed to do was figure out which wire was the hot
wire from the battery, ground wire and ignition wire in the mess of
over a dozen cut off wires that were laying by my old compressor. Even
the electrically challenged one was able to figure it.
So now I have an air system that I can control my Quadra Bag System
with a remote control that is about the size of a pack of cigarettes.
It has two programs that I can set whether I am running heavily loaded
or a light load. I can raise or lower each side's air bags
independently of the other or both at the same time. When I am finished
dry camping and have previously raised or lower one side or the other I
can press program I or II whatever I need and the coach rear ride
height readjusts to height I have set for travel. I can even stand
outside of the coach and raise or lower the rear of the coach with the
It is nice to finally have the air system working so that I don't have
to use my plug-in compressor to manually air up the bags. I can
now travel with the air bag valves open. If I were to loose any air the
system automatically comes on and readjusts to the programed air
pressure setting Ihave it set to. If the air system compressor were to
fail I have it set-up so that I can still manually fill the bags with
my old plug-in compressor. Gary Bovee - 8-20-10
Here is a link to my pics -
Bovee’s Wireless Air System
1. How Did I Decide
GMCWS - KING CITY
The original air system in our coach was not functional. The PO made
numerous modifications and had cut off all the wires at the air system
never finishing the project. I had no clue where to start.
So I decided to start from scratch. I did my homework and found a
GMCer (John Shotwell) from the Eastern States Club that had installed a
wireless air system. I studied his setup and then made a couple
tweaks of my own (added ss air pressure tank & water trap).
How does the System Work?
2. This is a pressure based system. It uses no
leveling valves. If you are running only on Schrader valves, then it
will be basically the same concept EXCEPT:
a. No more having to go to the
bags to fill or release air;
b. No more having to drag out a
compressor to air up your bags for travel.
c. You program the remote digital
controller for the proper ride height and it will automatically keep
the bag’s air pressure within plus or minus 3 pounds of the programmed
setting for each bag.
d. The nice thing is – when you park at an RV
park or are dry camping you use the remote to level your coach.
e. When you are ready to hit the
road you just push the programmed button for road travel. It adds or
releases air, whatever is needed for each bag and you are soon on your
way. (This system has a
maximum air pressure limit of 100 pound.)
3. Where is the
The system in my Royale is located under the driver’s side bed. You
could locate it just about anywhere you want that has enough room for
the system. The system only needs three wires to hook it up: One
wire from the ignition switch, one hot wire and one ground wire. It
could be used on any of the GMC models to replace the original air
4. My Wireless Air
a. Viair Compressor - # 450c
b. Norgren - Water Trap - F07
c. Stainless Steel Pressure Tank - #104
d. 40 Amp Relay – Applied GMC
e. Air Lift Kit - #72000 – Applied
* The Wireless Air System
has a built in function that will automatically shuts off the
compressor if it tries to run continuously longer than 3 minutes.
It will then shut off for 7 minutes before becoming operational
again. It will work on an off like this until the bags are filled
to the pressure you have set in the wireless digital controller.
This is the problem of using a compressor that is too small and can't
fill the bags in less than 3 minutes.
If you are going to be using the Wireless Air System to level your
coach when parked, I recommend using a compressor that has a 100% duty
cycle rating unless you don’t mind waiting 7 minutes between shutdowns.
If you are only going to be using the Wireless Air System to keep your
bags within plus or minus 3 pounds of the settings for the bags you
have programed in the wireless digital controller a smaller compressor
will work just fine
a. Viair Compressor - $249.00.
b. Water Trap - $19.00. Technical
support at Air Lift suggests that you should use a water trap with the
air system being used in this manner.
c. Stainless Steel Air Pressure
Tank - $89.95 - Technical support at Air Lift suggests that you should
use an air tank with the air system being used in this manner.
d. Relay – $7.95 -
e. Air Lift Kit - $380.00
Jim K. at Applied GMC can supply the wireless
kit for , Viair 450c compressor $249, ss tank 89.95, and
water trap for $19. He can supply everything
you will need -Bovee 5-12-11
Airlift instruction manual down load