The following information came from several email lists relating to Jeeps and Jeep modification, particularly in terms of using Jeeps off road.  I've removed individual's email addresses in order to protect their privacy.  I have, however retained their names in order to properly credit the original authors.  The JeepTech list is hosted by off-road.com, you can find subscription info in their tech section.  I also recommend their technical articles.  They have some very knowledgable Jeepers writing for them.  A newer list is called JeepOffroad, or JPOR.  Its for people who want to talk about Jeeps and driving them off-road.  The last list is the Jeep-L, or Jeep List.  Their web page is hosted by off-road.com, but the list server is somewhere else.  In any case, signup info is at the web page.


 --------

On-Board Air Compressors   (( from YJ FAQ ))
 

I just finished a on board air setup on my 85 CJ-7.  I used
the compressor that came with the Jeep which is the "newer"
type that everyone tells you to stay away from.  The
"oiling" of the air was a problem.  The first thing out of
the compressor is a dryer.  Out of the bottom of the dryer
(where the drain goes) is plastic pressure tubing that is
routed back to the inlet of the compressor thru the
recharging valve.  The valve is cracked open slightly to
permit the oil to return to whence it came.  On the inlet of
the compressor is a craftsman lawn mower air filter.  Adds
character.

After the dryer is a check valve. This prevents the pressure
from leaking back to the intake of the compressor.  Next is
a "pop off" valve.  This of course prevents explosive
events.  It is adjustable to 125 PSI.  Next is a three way
manifold.  Saves space;  saw it at Sears.  In  one outlet
port is a pressure switch.  12V from switch on the dash to
the pressure switch, other leg from pressure switch goes to
compressor clutch. Second outlet goes to a female quick
connect in the grill.  Third outlet passes thru a adjustable
regulator and then on to a pressure tank.  The reason for
the regulator is to make sure to keep pressure within
tolerances for the ARB.  Of course I need to know what is
going on so there is a air pressure gauge in the dash.  A
green light to let me know that the compressor switch is
enabled, and a orange light to let me know when the
compressor is running.

Just completed this setup a week ago.  It does NOT subscribe
to the KISS theory but it was fun to design and implement.
Time will tell about the oil scavenger.  Will it work or
will I fry the compressor.  My local parts store, that I
have developed a good relationship with, made all the hoses
for me. No hose clamps!

- Bill Davis

--------------

From: Brian Simon
To: Jeep-L
Subject: Re: Factory Air conditioner compressor.
Date: 10/28/97  13:27

Steve3:
I have the 4.2 in a 90 with the factory air.  First, I don't know what my compressor is, but its not a York.  2) My understanding of the issue is that (as Bud implied) the 'factory' compressor is one thats lubed by the goo in an a/c system.  Using it for plain old air will require some mechanism to add lube to the compressor and also filter that lube out before it goes into your tire / air tool with the compressed air.

Those of you looking for a York (which supposedly doesn't have the above problems) for the 258/4.2 are supposed to go find an AMC with the 258 from the early eighties.  This will give you the York compressor, plus the appropriate mounting brackets for your motor; theoretically at a low price.  I've heard $20-$40.

bs

One of the Wheeling Piazza Bros:
>
>I have a question. With all this topic about on board air, I was =
>wondering, What did Chrysler use for there factory air compressor for =
>the air conditioning? and will it work for on board air?

--------------------------

From: Brian Simon
To: Jeep-L
Subject: Re: On-board / Jeep compressors
Date: 12/22/97  16:08

Chris-
This was covered not too long ago, but that might have been on Jeeptech (speaking of which, is that still up??).  Anyway, here's the deal, or at least my take on it:  I have a 90 YJ with the 258 & a/c.  I have v belts.  There are 3 of them:  1) power steering to h2o to fan; 2) h2o to fan to a/c; 3) a/c to alternator.  Don't know what kind of compressor I have.  Part 2:  If you want a York compressor, you can find them on early to mid 80s AMC cars (i.e. eagle) with the 258.  Rumor has it that folks have found them for $40-50 including the mounting brackets necessary for your motor.  Which would be pretty cool (hahaha).  Part 3:  I haven't done this yet, but plan to.  My understanding is that I can use the existing compressor, but may need a pre-oiler and/or a filter for the air coming out.  I think someone on the list has done all this, but being the meathead I am, did not keep the info.

bs (just call me an airhead)

>From: Chris Waterman
>
> The only real 'pro' I can see is that it's meant to go in a
>Jeep, so mounting is a snap.  Only problem is I'd have to convert
>over to the serpentine belt system - I couldn't see a single A/C
>system for the v-belt setup that's in my '89 YJ.  Has anyone out there
>done on-board air on a 258 with the twin v-belts?  Got pictures?
>
>Chris

==============================

Topic No. 7

Date: Mon, 22 Dec 1997 19:54:27 -0800
From: Bud Boren
To: jeep-l@knuth.mtsu.edu
Subject: Re: On-board / Jeep compressors

Chris Waterman wrote:

> Hey all -
>
>         So I was out at the local wrecking yards this weekend and saw
> several '80s cherokees (and a Wrangler) with A/C.  The compressor in
> them had a Japanese-sounding name (not Neppondenso) that I'd never
> heard of before, but it seemed pretty universal for the serpentine-
> belt pulley setup, where it mounts on top of the alternator.
>
>         My question (there had to be one) is is this compressor
> suitable for an on-board air setup?  Is it one of the ones that's
> lubricated by the coolant, or does it have an oil reservoir?
>
>         The only real 'pro' I can see is that it's meant to go in a
> Jeep, so mounting is a snap.  Only problem is I'd have to convert
> over to the serpentine belt system - I couldn't see a single A/C
> system for the v-belt setup that's in my '89 YJ.  Has anyone out there
>
> done on-board air on a 258 with the twin v-belts?  Got pictures?
>
> Chris

  Chris:

  The Nependenso is a rotory compressor. Unlike the York it does not
have it's own reservor. You would have to give it some kind of an oiler
which is no big deal.  That's the one I have been using for many years.
It doesn't take up the room the York, even the so called baby York does.
You can get them with serpentine,combo of serpentine and v groove or
v-groove pully's. You aren't looking hard enough. They come in all
configurations. You are running a v-belt, so find one that is also
running a v-belt. There out there. Or change the pully.  I love mine. It
kicks butt.

  I got mine from a late model Chevy or something like that. It's nice
to get one that fit's without having to make a bracket, but there are
many trucks out there that have exactly what your looking for. It's a
very cool thing to have on your truck and once you have it you will
wonder why you waited so long to get it.

Well, good luck in your search. Check out: Obi Wan's setup.
 There are other sites too so you can check them all out if you like,
but they are all on Yorks. The rest of the info would apply to your set
up if you decide to go with the Nepo instead.

  Bud Boren
 
======--------==========

Date: Fri, 09 Jan 1998 17:02:11 -0600
From: John Nutter
To: jeepoffroad
Subject: Re: JPOR: The York A/C compressor mod

Ed,

Any of the full sized Yorks should be fine. They are all roughly 10 Cu
In displacement, so it doesn't matter which one you choose. I'd try to
find one that is mounted to the same engine that you have in the Bronco.
That way you can get all the brackets and pulleys.

I'd try to avoid Ready Air altogether. They are kind of like the
Advanced Adapters of underhood air -- they have things *they think* you
can't get elsewhere and charge a lot of money based on that. I've not
heard anything bad about them, but their prices seem pretty outrageous
for something you can make from readily available junkyard and hardware
store parts.

EdTapanes wrote:
>
> Howdy all,
> I'm looking to do the York A/C to on-board air compressor mod. I know this
> modification has been beat to death, but I really wasn't ready to do it until
> now.  I've soaked up as much info as possible off the web (like Jon Hanna's
> page) but have only come up with more questions.  I know there are a couple of
> variations of Yorks (including the mini-York), and even more variations of
> mounting them, but my main question is what is the most desireable York unit
> out there and what donor vehicles can I get it from?  Would it be worth
> finding one out of a similarly engined vehicle for the bracketry and such and
> then seeking out the more desireable unit (if there actually is such a unit)?
> I also heard that "Ready Aire" sells 'hop up' kits for them, etc.  Does anyone
> have this company's ph#?
>
> Any info (or pointers to sources of info) at all would be greatly appreciated.
>
> TIA,
> Ed T.

John Nutter  '85 CJ7

------------------

Date: Fri, 9 Jan 1998 15:38:03 -0800
From: Chris Waterman
To: jeepoffroad
Subject: Re: JPOR: The York A/C compressor mod

Ed -

  You can get the compressor and brackets out of almost any
AMC car with A/C: Gremlin, Concorde, Pacer, etc.  It's definitely
a good idea to get all the brackets, belts, and bolts you need
off the donor vehicle - and make a drawing or something so you
remember how to put it all back together <g>.  I got all my stuff
out of a Concorde, and ended up using its belt and running it the
same as Jon Hyland (see www.huv.com/jon/jeep/Air/index.html).
That meant I had to make a simple bracket for an idler pulley, but
no big deal.
  Concensus seems to be that an upright (vertical) mount York
is best since it spits out the least oil from the outlet port.  I
don't know much about other models, I'm afraid...
  One useful tip: you can get York compressors out of Volvo
wagons and one or two non-AMC domestic models (look around).  The
pulleys may be different, though, but the Volvo model is close enough
to be usable, according to Jon's page.  So that gives you some latitude
for finding a compressor in good shape.  Test it before you buy it!
  All this assumes you've got an AMC engine, by the way.  My
258 and Jon's 4-cyl seemed to go together the same way.  YMMV!

Chris
'89 YJ w/ 258

> <snip>
> but my main question is what is the most desireable York unit
> out there and what donor vehicles can I get it from?  Would it
> be worth finding one out of a similarly engined vehicle for the
> bracketry and such and then seeking out the more desireable unit
> (if there actually is such a unit)?
> <snip>

============

Date: Sun, 18 Jan 1998 18:15:05 -0500
From:  (Damon F Gentile)
Subject: current for switch vs. relay

Now that I'm trying to figure out the easier parts of the
onboard air setup, I've got a question about when to use
a relay and when to just use a switch.

I need to switch the clutch on the compressor, and
that takes about 3A. Should be no problem for a wire under
the dash to handle it- I could splice it right in to the
cigarette lighter/acc line.

But sould it be better to mount a relay for it ? It would
really be a PITA. Like getting under my battery tray to
get a hot wire onto the starter solenoid, and mounting
a relay.

Is there a guidline for how much current requires a relay
or should I just use a simple switch and forget it ?

Later there will be a pressure switch and this switch will
become a master disconnect.

Thanks,
- -Damon           V-belt York on a YJ !
 

===========

Date: Sun, 18 Jan 1998 18:29:54 -0600
From: John Nutter
Subject: re: current for switch vs. relay

> Now that I'm trying to figure out the easier parts of the
> onboard air setup, I've got a question about when to use
> a relay and when to just use a switch.
>
> I need to switch the clutch on the compressor, and
> that takes about 3A. Should be no problem for a wire under
> the dash to handle it- I could splice it right in to the
> cigarette lighter/acc line.
snip:

> Thanks,
> - -Damon           V-belt York on a YJ !

Most switches have a rated amperage written on the body of the switch or
the package. . You should be able to find a heavy enough switch to
handle 3A.

- --
John Nutter  '85 CJ7

===> Message End <=============================================
This mailing list is proudly sponsored by Off-Road.com, Inc.
http://www.off-road.com

------------------------------

Date: Sun, 18 Jan 1998 17:20:07 -0800
From: Whit
Subject: Re: current for switch vs. relay

I spent my day rewiring my ARB compressor so I have my opinion on this.
The specs I have say the power to the compressor can be up to19 Amps but is
switched by a relay.  I put a switch in the relay circuit so the compressor
would not come on everytime I started the engine.  The relay circuit is
probably closer to 3 Amps (just a wild ass guess).  If you are only need to
draw 3 Amps I would not worry about a relay.  For comparison data, your
tail lights use about 3 Amps and you can run 20 guage wire for over 30 feet
without needing to use thicker wire.  This setup sounds very similar to the
ARB setup.  If you want the wiring diagram I would be happy to Email it to
you.

At 06:15 PM 1/18/98 -0500, you wrote:
>
>
>
>Now that I'm trying to figure out the easier parts of the
>onboard air setup, I've got a question about when to use
>a relay and when to just use a switch.
>
>I need to switch the clutch on the compressor, and
>that takes about 3A. Should be no problem for a wire under
>the dash to handle it- I could splice it right in to the
>cigarette lighter/acc line.
>
>But sould it be better to mount a relay for it ? It would
>really be a PITA. Like getting under my battery tray to
>get a hot wire onto the starter solenoid, and mounting
>a relay.
>
>Is there a guidline for how much current requires a relay
>or should I just use a simple switch and forget it ?
>
>Later there will be a pressure switch and this switch will
>become a master disconnect.
 

Whit
 

------------------------------

Date: Sun, 18 Jan 1998 17:22:34 -0800
From: Whit
Subject: re: current for switch vs. relay

>
>Most switches have a rated amperage written on the body of the switch or
>the package. . You should be able to find a heavy enough switch to
>handle 3A.

I just bought a 30A switch from Radio Shack.  Not becuase I need 30A but I
liked the looks of it.  $1.89 was the cost.

Whit
 

------------------------------

Date: Sun, 18 Jan 1998 21:33:05 -0500
From:  (Damon F Gentile)
Subject: Re: current for switch vs. relay

Oh sure. I've already got a switch selected - for looks,
but it's a 20A. I didn't give any concern to over powering
the switch, just routing a few amps of current under the dash.

I think I'll just switch it.  AFAIK the a/c clutch is current-
operated, and a little voltage drop in the line should be okay.

- -Damon
 

Has anyone ever tried to run a potato cannon powered by an
on-board air setup?  I can see it now...

Sierra club, 2o'clock.
Fire in the hole!
Fwoooomp.
Okay, here's the new trail...

heh heh heh.

------------------------------

Date: Mon, 19 Jan 1998 21:13:14 -0500
From: (Damon F Gentile)
Subject: Re: current for switch vs. relay

>Where did you get that 3A number?  I suppose I could hook up my
>ammeter inline with the circuit...

When I first got the unit I powered it up on the bench to get some
idea if it worked and it's current draw.  Running it at 12V (yeah,
I shoulda used 15) it took 3 amps to hold the clutch in.  This was
obviously static without fast RPMs on the compressor but I think it
should
be fairly constant.

>
>I just finished a similar setup on my '95 YJ.  I had originally
>wired it for a relay, but I axed that idea when I couldn't find
>a convenient hot wire in the engine compartment.  I ended up

You could use any hot for the relay as long as you have a master
switch inside. Ideal place to take the hot from is the starter solenoid.

>just wiring a direct circuit from the lighter/acc line to a 30A
>switch to a pressure switch to the compressor.  I've used it
>several times, and have yet to see any problems.  I keep meaning
>to insulate the connections to the under-dash switch.  One of
>these days I'm going to get quite a shock if I'm not careful.
>
>: Is there a guidline for how much current requires a relay
>: or should I just use a simple switch and forget it ?
>
>Not directly.  It's more a function of how much wire you must run
>from your switch to the device.  The longer the wire, the thicker
>the wire must be to maintain a high current.  There's also the
>saftey issue of sending all your current through a place you're
>likely to touch with your hands.
>
>: Later there will be a pressure switch and this switch will
>: become a master disconnect.
>
>For $15, I'd recommend adding a pressure switch right off the bat.
>Not having one makes filling tires a two-person job -- one to fill
>the tires, and one to monitor the pressure gauge and run the toggle
>switch.

Yes, you are right. Since my air tank now has humungoid holes in
it, (thanks FWPW!)  I was planning on running straight off the
compressor. Now I see that you can use the pressure switch on that
small volume of air in the pipe.

FWIW, I put all of my connections extra loose to air up tonight - I
even had one of those adjustable nozzles vented to atmosphere.
I was only able to put out ~30# so I didn't worry about blowing
any connections.

Hoping to get the last odds and ends taken care of tomorrow.

>
>: -Damon           V-belt York on a YJ !
>
>Been there, done that.  Royal PITA, but it's sure nice to have now
>that it's basically finished.  I'll need to add an idler pulley
>once I learn how to weld it myself.

Well Chrysler let me cheat a bit.  I started with a v-belt system.
Gotta love them CJ leftovers!

>
>I'll have to try that potato cannon idea!
>
>     -- Obi-Wan

Good luck with it.

- -damon

===> Message End <=============================================
This mailing list is proudly sponsored by Off-Road.com, Inc.
http://www.off-road.com

------------------------------

Date: Wed, 11 Feb 1998 01:33:47 -0800
From: Ed
Subject: Re: Air Compressor w / AC Motor

I've heard that Slick 50 does wonders replacing the original oil.  Drain the
'ole stuff, add Slick 50, run for a while (??), drain it, seal it.  Your
done.

Ed
 

Chad Geidel wrote:

> following the york air compressor thread got me to thinkin...
>
> i am planning to make an air compressor out of my air conditioning motor
> (why anyone would want A/C in a jeep is beyond me) and would like some
> suggestions.  have any of you tried this?  run into any problems?  i
> know that i will have to keep it oiled, what oil should i use and how
> often?  i am thinking about using some heavy pvc pipe and a pressure
> gauge (so i don't blow the pipe), i know that this is not "recommended"
> but i think if i keep it under 100 psi this won't be a problem (schedule
> 60 is rated to 300 psi).
>
> any advice, warnings, etc.  would be appreciated.
>
>   --  chad
>       '90 Wrangler, 258, Auto., Stock.  Shiny Yellow!
>       http://silver.sdsmt.edu/~clg4546/
>
>     "DEA guidelines established in 1989 define 'uncool' kids as
>     those who 'are introverted and passive; possess academic aptitude
>     and physical ungainliness; and live in constant fear of things
>     that really aren't that big a deal.'"
>

- --
Ed Cox
http://www.datastreme.com
 
 

------------------------------

Date: Wed, 11 Feb 1998 09:14:40 -0800
From: Mike Will
Subject: RE: Air Compressor w / AC Motor

  I wouldn't use PVC pipe.  The Pipe itself is rated for the pressure, but
not the heat.  See, air coming out of the compressor will be HOT and the
heat will either ruin the glue holding the joints together or it will
weaken the pipe until it fails.  You can use copper tubing or black iron
pipe.  I'd suggest the tubing as it's easy to work with and light weight.
  The amount of oiling required in the pump really depends on the pump
itself.  The York compressors are piston driven and have their own oil, so
in effect, no more oil is necessary.  The wobble-plate ones found in most
newer vehicles are designed to be lubricated by the refrigerant, so they do
require oil.  I would use air tool oil, and I would do one of two things:
I'd either pour a bunch of this oil in every time I used it, and about
every half hour there after, or I'd install an in-line oiler that would
keep an oil "fog" in there at all times.  Either way, you'll want to
install some sort of trap to catch all the oil after it runs through the
compressor (you don't want to fill your tires or blow down anything with
oily air), and you probably want to install a water trap before the
compressor so that the oil doesn't get al milky.

Mike.
 

------------------------------

Date: Tue, 10 Mar 1998 22:36:56 -0800
From:  (larry soo)
Subject: york oil fix

This came from Vern O'Connor, director of the Island Rockcrawlers 4x4 club
and all around mechanical genius:

HOW TO STOP THE YORK FROM PUMPING OIL INTO THE AIR

>Pull off the pulley and look for a diagonal rib running from the head
>of the pump down to the bearing. This is the oil passage. There may be
>two. Only one will be drilled.
>Remove the bearing cover and using a #10 (1/8") NFT tap, thread the
>passage about 3/8" deep. Cut the head off a fine thread # 10 machine
>screw, hacksaw a slot in the end of it, using Loc-Tight wind it in
>till it bottoms in the threads.
>Pretty easy.    PS don't pull off the head. There is a very complex
>gasket that always tears.
 

...lars
 

------------------------------

Date: Wed, 11 Mar 1998 13:17:25 -0600 (CST)
From: Obi-Wan
Subject: Re: York Compressor Question

DaveO,

[ discussing the use of a check valve in a York compressor, supposedly
  to reduce the pressure on the exhaust port of the York. ]

> Sorry if I seem so dumb

No problem.  I was in the same boat six months ago.  Maybe I'm still there.

> However, I am still unclear as to how the pressure could
> drop at the exhaust port if the check valve is in place. It would seem that
> the entire system (even with check valve) would remain at the same PSI
> unless there is some sort of bleed-off (or leak) within the compressor (or
> on the compressor side of the check valve) to allow it to release pressure.
> I assumed the check valve was simply a one-way valve (like a diode). Is
> there a bleed-off on the valve?

Yes.  No.

> I still don't
> see how, in a closed system (the exhaust port plus tank with no tools being
> used) that the check valve performs a function. If you were to put a
> pressure guage before and after the check valve, when and why would they
> read different pressures (unless you have a regulator on one side)?

When the compressor is running, the same pressure exists on both
sides of the check valve (both in the exhaust line and the rest of
the system).  When the compressor shuts off and the pulley clutch
disengages, the 100 psi in the exhaust line will force the compressor
to turn backwards...whoa, wait a minute, that doesn't make sense.

I was going to say that the compressor will turn backwards for an
instant, releasing the pressure in the exhaust line.  That can't be,
though, because systems without a check valve (like yours) don't
empty themselves when they shut off.

Maybe the compressor does back off just a bit when it shuts off,
allowing the back pressure to be reduced but not eliminated.  Then
again, maybe those who instructed me were wrong, and I just blindly
followed them.  Maybe I wasted $13.

I'll copy this to JeepTech in search of a good answer.

    -- Obi-Wan
       '95.5 YJ

- --
Ben "Obi-Wan" Hollingsworth
 

------------------------------

Date: Wed, 11 Mar 1998 12:43:13 -0700
From: "Christo Slee"
Subject: Re: York Compressor Question

If you use a pressure switch with a bleed-off, this will drain the section
before the check valve, thus allowing the compressor to start up without a
load.

Christo Slee

------------------------------

Date: Wed, 11 Mar 1998 15:04:36 -0800
From: Ed
Subject: Re: York Compressor Question - bleed-off

Obi-Wan,
I run the York with a pressure switch with a bleed off.  It works like this.
Assume for this example that the tank is empty.  The compressor pumps air
through the line, through the pressure switch, then into the tank.  When the
tank pressure reaches 125psi, the pressure switch trips, turning off the
compressor AND releasing the pressure in the line from the compressor to the
tank via the bleed-off valve.  The Tank is sealed with 125psi.  When the
pressure in the tank drops to 80psi, the pressure valve trips, turning on the
compressor.  The compressor then repressurizes the tank to 125psi again, and the
cycle starts again.

Note:  when the check valve opens an 80 psi, air pressure fills the line from
the tank to the compressor, so the compressor does not start with zero back
pressure, but it is significantly less than the pressure it would have started
at.  In my case, the line from the compressor to the tank is about 10 feet long,
so the pressure is even less.

Hope this helps!

Ed Cox

Obi-Wan wrote:

> Christo Slee wrote:
> : If you use a pressure switch with a bleed-off, this will drain the section
> : before the check valve, thus allowing the compressor to start up without a
> : load.
>
> Huh?  Is the bleed-off independent from the line being measured?
> If not, it would seem that your switch would immediately kick back
> on as soon as it bled off.  My pressure switch has no bleed-off,
> but I had the option of getting one that did.  I didn't see the
> use at the time.  Please explain.
>
>                                 -- Obi-Wan
>                                    '95.5 YJ
>
> --
> Ben "Obi-Wan" Hollingsworth
>
 

------------------------------

Date: Wed, 11 Mar 1998 15:26:35 -0700
From: "Christo Slee"
Subject: Re: York Compressor Question

The pressure switch I used is similar to the ones used on garage
compressors. As soon as the full pressure is reached and the switch cycles
off, it opens a small vent to bleed of air. This vent has a connector that
can be plumbed to the circuit before the check valve. The bleed valve is not
connected to the main air inlet for the switch.

Essentially the switch opens a valve when switched off as well as switching
an electric circuit. The electric circuit is for the power to the compressor
and the valve is to bleed the system.

I did not connect this to on my system because I could not locate an in-line
check valve in time. I also figured that since the AC compressor always
start under pressure it would be OK, worst thing is the V belt will slip.

The need to bleed the air is for normal compressors with electrical motors.
By bleeding the pump side of the circuit, it is easier for the motor to
start.

As for people that worry about the oil, just run Slick 50 in the compressor
for some time and it should be OK for running dry for short periods of time.
I installed a oil trap and just drain it when needed.

Christo Slee
 

----------------------------------------------------------------------

Date: Thu, 12 Mar 1998 08:38:59 -0500
From: Dave Oshman
Subject: RE: York Compressor Question

>Date: 11 Mar 1998 17:51:13 -0800
>From: Kirk Beasley
>Subject: RE>Re: York Compressor Ques
>
The check valve idea should work if there is some sort of bleed-off valve
before the pressure switch and check valve.

           electrical feedback
_____/---/----------------------\           ____
|   |===||==========>>=========\||/========|    |
|   |  bleed-off  check      pressure      |tank|
|___|             valve       switch       |____|
compressor

Perhaps there is one that is electrically actuated so that when the
compressor turns off, the bleed-off valve goes on. Of course, it would need
to be able to turn itself off or run constantly. Or perhaps when it is
"on", it is closed so that when the pressure switch goes off (no voltage),
the valve opens. Does anyone know if such a valve exists? Obi-Wan, check
your Surplus City catalog--I haven't gotten mine in the mail yet.
DaveO
>RE>Re: York Compressor Question
>>The pressure switch measures from the tank side of the check valve.  When the
>>pressure builds and the compressor turns off, the pressure in the line
>>between the check valve and compressor is bled off.
>
>So does this means a pressure switch  with an integral bleed-off
>feature also contains a check valve as a single assembly, or does
>it just get plumbed in parallel with a separate check valve?
>
>Kirk
>
>

------------------------------

Date: Thu, 12 Mar 1998 11:26:08 -0800
From: (Chris Waterman)
Subject: RE: York Compressor Question / unloader mechanism

Dave / Kirk / Obi-Wan/ etc.

 The feedback mechanism you're looking for is available,
but it's pneumatic, not electric.  You need to get the pressure
switch and check valve with unloader ports.  When the switch
turns off, it activates its unloader output, which in turn forces
the check valve to vent the air in the hose going to the compressor.
Physically, it's a small hose that goes from the switch to the
check valve.  This system adds a fair bit to the cost of the switch
and valve (like an extra 20-30%), plus you gotta buy the extra hose,
which may have to be hard line depending on the fittings.  Some of
the guys with on-board air pages have done this, but I can't find
the URLs.  Anyone?
 Personally, I didn't bother.  I got a check valve with an
automatic unloader (called a genie valve), that unloads the hose to
the compressor when the pressure on the tank side equals the pressure
on the compressor side.  It hasn't worked very well - damn thing
leaks like a sieve.  I wonder if the air volume from my York killed
it.  I'll probably just yank the thing and put in a regular check
valve.  That way, any leakage inside the compressor won't drain my
tank if I've got it pressurized for a long time.

Chris
 
 

------------------------------

Date: Tue, 28 Apr 1998 15:45:08 -0700
From: Steve Piazza
Subject: RE: Nippendenso compressor

       I run the factory A/C pump on my YJ,  Pretty sure its the
nippendenso, I have not had any problems with mine, I air up two tires
at a time, and I have no problems keeping up with the guys that have
Yorks.  I say from 5 psi to 30 in less then a min. on a 33X12.5

      I run a 2.5 gallon sun performance tank. with an oil separator and
a couple of other things. I have a nifty diagram some place if you want
to see it let me know I will dig it up someplace..

     A couple of things you will need.

     !. a decent oil/water separator.
     2. A 150 or smaller pop off valve.
     3. Automatic shut off valve. Mine shuts of at 150..
     4. Some copper line coming out of the pump, Everything else will melt or get really hot.
     5. A 1/2 to 1/4 reducer
     6. a small piece of hose and a small air filter for the intake.
     7. Misc. connectors and hose.

     I think thats about it...

     Steve Piazza

          Steve Piazza
ONE of the WHEELING PIAZZA BROTHERS.
89 YJ, 4 inch Procomp, 33's rs9000's,M8000 Warn
74 CJ 5, 2.5 lift,2 inch body, 33's
76 Chvy 4x,6 inch Procomp, 35's, Lava Lined tub

Worksucks I am going wheelin..



Other pages with on-board air info:

I started doing mine, finally, in December 1998. First email on the progress of the project:


Posted-Date: Fri, 11 Dec 1998 19:48:46 -0600 (CST)
Date: Fri, 11 Dec 1998 19:48:38 -0600
From: Brian Simon
Subject: Re: JPOR: Air Conditioning Pump

Chuck-
Yes, it is possible. I am partway through this project with my 90 YJ.
There are a bunch of web sites detailing a variety of ways to do this. I
have saved a bunch of emails on the topic from different lists at:
http://www.visi.com/~bsimon/jeep/air.html

also try:
http://www.jedi.com/obiwan/jeep/yorkair.html
http://www.huv.com/jon/jeep/Air/index.html
http://users.success.net/luv2jeep/on-board.html

In a YJ with the 258, there is a rotary compressor on the right side of the
motor below the alternator. Your system may be different. Also, you
should have a garage discharge/drain your system. Around here, some places
will do that for free.

In my particular case, I found it easiest to use the existing wiring, as my
Jeep came from the factory with a/c. First, I removed the condensor in the
front (mine was between the grill & radiator) and the vent/motor/switch
piece of the dash. There were just 4 screws holding this piece. I wired a
lighted rocker switch to the two wires that went to the on-off switch of
the a/c.

Under the hood, there's a little canister with a/c tubes and two wires
going to it. Inside this there is a pressure switch that keeps the a/c
from running if the system is empty. I removed the cannister and, at this
point, have just spliced the two wires together. So for now, only the
switch in the dash controls power to the a/c magnetic clutch. When the job
is done, I will put the system pressure switch at this point, so I first
have to have the dash switch on, then the a/c will only pump if system
pressure is below 80 psi. The pressure switch will also shut the system
off when pressure exceeds 120 psi.

bs (have the switch working & air coming outta the compressor!)

At 01:48 PM 12/11/98 +0000, OS1 CAROTHERS CPR7/N3 7230 wrote:
>Hi Peoples
>
> My question for the day is. I have heard of people converting their
>air conditioner pump into an air pump to inflate tires while on trail
>rides. Has anyone seen this application or have it done on their
>ride. Or am I totally off hear and it can't be done. If it can be
>done, how is it done.
>
>Thanks
>Chuck
>84 Scrambler
>


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