Aux. Air compressor

[Chaz]

Hey guys,
  I was reading the "leveling" thread and got thinking about the Air Compressor (Sears) I bought  to get the air up before I start up.
  I'm not sure how many Hot Rodders or Car Nuts we have here but, what about the little Air Compressors they use for air ride suspensions in Hot Rods and Fart Can cars that are "slammed on the ground"?? It's my guess they would work, but maybe they won't for some reason.  If they would work, they are small, compact and light. There are obviously different sizes depending on the cfm's you need.  Anybody used one yet?

   Curious yet again,
      Chaz

[Ncbob]

I have two aux. compressors but only carry the one that will go to 125 PSI...both for the tires and the air suspension.

Bob

[HighTechRedneck]

This was discussed at length a long time ago here.  I didn't have much luck quickly trying to locate the thread.  But as I recall, the consensus was that those air compressors are great for airing up before starting or for maintaining air while parked.  And in an emergency situation they might briefly serve as a backup to a failed main compressor on level ground.  But only with infrequent braking and certainly not on any grades (they don't have the volume capability to support repeated braking).

[HB of CJ]

No I haven't.  Actually quite a good idea as it allows us to '"boggie" quickly in an emergency.  We can also air up quietly (?) and sneak out of the campground without paying the bill.  He he he, just kidding. 

[Chaz]

This was discussed at length a long time ago here.  I didn't have much luck quickly trying to locate the thread. 

I am familiar with that thread. That thread is actually why I bought the Sears A.C., that some of the other guys said worked well. It does do fine! A little bulky tho.
  But I was just thinking that since space is at a premium, I should have looked at the air ride compressors. They are WAAAAAAAAAY smaller. And, I think, quite a bit quieter. It may take them a little longer, but..................... trade offs.............. ya gotta have'em.

  Thanx,
     Chaz

[Hartley]

Some say the reason for a 15 cuft /min air compressor is because while driving you need all the fast recovery available for brakes and suspension.

TU FLO 700 & 750 meet that need. Unless they break... A Carry along compressor to be used for emergency use should be at least 5 cu.ft /min. It would get you off the road if you are careful.

I have a dewalt 4.5 that does the trick but won't air up the bus from dead zero in less than 20 minutes.

It's hard to start working on suspension leaks when you are living in the bus.. The wife starts fussing about the noise and stuff.. Go figure... I know where mine are anyway as it's a NJT MC9 I didn't plate the drivers side rear earlier because it wasn't leaking.
I guess I will have to do that before long...

Dave....

[pvcces]

We stuck with 1/2 hp to make sure it would not be a problem starting on the old 2000 inverter. If we haven't parked so long that the air bags are low, we can get pressure up in about 10 minutes or so.

Flat air bags can pretty well double the time. Tankless with a pressure switch makes a good combination. Be sure to find out how noisy the compressor will be before buying, if you can. They tend to be loud.

For what it's worth.

Tom Caffrey

[PP]

I'm not familiar with the little compressors being used on hotrods, but I use a 1/2 horse plumbed into my leveling system for when I'm parked and added a moisture trap between it and the system. I drain it every week and am surprised at how much moisture dumps out of it. FWIW this is something worth keeping in mind for preventing both rust and freezing in the components. Will

[Melbo]

On the compressors I've seen lately ( I am in the market for a portable one for work ) there is a db rating so you can compare the noise level before buying

HTH

Melbo

[Chaz]

If you are looking, Melbo, check out Air Ride. They make air ride systems for Hot Rods. But I'll for warn ya.........they are "proud" of their stuff!! But It's probably as good as you can get. The bay has some listed also. I understand they are real quiet.
  OT- I am looking to put an air ride set up on my '56 chevy 210. If/when I get to it, I'll give ya all a report. But somebody may be able to beat me to it. 
Chaz

[Ednj]

This was discussed at length a long time ago here.  I didn't have much luck quickly trying to locate the thread. 

I am familiar with that thread. That thread is actually why I bought the Sears A.C., that some of the other guys said worked well. It does do fine! A little bulky tho.
  But I was just thinking that since space is at a premium, I should have looked at the air ride compressors. They are WAAAAAAAAAY smaller. And, I think, quite a bit quieter. It may take them a little longer, but..................... trade offs.............. ya gotta have'em.

  Thanx,
     Chaz

>
http://www.suicidedoors.com/AirManagementCompressors.php
Don't look at thier prices on air fittings.
Ed

[junkman42]

for those with 24 volt/28volt systems You might consider some of the military surplus from aircraft systems etc.  There are some very high quality compressors for very reasonable prices.  The reason only nuts like us have the desire for 24 volt air compressors.  John

[Tim Strommen]

I don't remember if this was brought up in the previous thread, but ensuring that you DO NOT bypass the air dryer is something that one should pay attention to.

An electric aux compressor can be plumbed in parallel to the prime-mover's compressor with check valves (or by using a dual check valve which is two check valves built into a t-fitting - how convenient!) to ensure the air doesn't find an easier way out than the air tank .  Keep in mind that the Governor is air powered and will still operate the "unloader" for the engine's compressor (pressurized control line = unloaded/purge) - if you tap in a standard air-brake brake light switch to the coil of a normally closed relay, you can use the factory governor to opperate the aux compressor demand (so that it won't turn on the compressor if the tanks are already full).

Most shop or other electric compressors have an electric pressure switch which will cut off the compressor motor when the tank hits a certain pressure (I say "most" because I've seen some of the large one that have a standard "D-2" type governor, and run the motor continuously).  This can be retained - but keep in mind that if your governor unloads the compressor and tells the air dryer to purge at 120PSIG but the electric air compressor's switch doesn't turn off until 125PSIG or 150PSIG - the compressor will never turn off by itself (and this may impact the dryer's dessicant regeneration "purge" cycle).

Cheers!

-Tim

[Dreamscape]

Here is a link that a buddy of mine has in his jeep. I have not seen it but he tells me they are tough and work great. Lots of ways to go. http://www.wheelersoffroad.com/viair.htm

HTH,

Paul

[Sojourner]

About 12v air compressor
1)   Battery power pump is good for direct coach power source.
2)   20% duty cycle @ 100 psi is not good
3)   .88 or 1.27 cfm is very slow
4)   Cost more than higher 4.5 cfm at 110v ac.
5)   Smaller than larger 110v ac ones

Battery power unit are usually not design to run more than 20 minutes at a time so it can cools.  They have no good air flow thorough winding for continues running time. It not designs for your large bus air storage tanks. Unless you want maintain over night air pressure for very small leakage or very small supply of air source.
Example it would take about 20 minute with 4.5 cfm as quoted from the DrDave's above post....12v pump would take about 3.54 to 5.12 times longer running time to meet what a 4.5 cfm @ 100 psi.

Remember always look for compressor for cfm at what psi with good cooling fan.  You want one to be able to pump at least 125 psi. Look for greatest cfm for the money at 100 psi. @ 4.5 or greater at 100psi is the bus's favorite in the practical sense.

Also remember to double fuse rating for air compressor's starting power requirement.

I would suggest looking for ones that is oil-bath crankcase version. Also look for ones that motor frame is metal case....not plastic. In time plastic will warp to cause armature clearance to stator to touch and burn up. And motor is direct drive to pump for compact design, however it nosier than belt driven version but it physically somewhat larger unit. Of course belt drive is one more problem to keep in check for tension.

So find a unit that fix your need such as pancake version take up little more room then square package unit.

Caution what ever you do put in a one-way check valve in circuit and allow some cooling air around compressor.

As per Tim Strommen posted...by all mean do what he said.....otherwise you are going to get moist into tank after dryer to cause freeze up in colder climate unless you drain check it for water every time you pumped with aux. pump.

FWIW

Sojourn for Christ, Jerry