Using the bus air compressor to air up makes a lot of noise as I was aware of but already encountered my first complaint. :(
I'd like to add an external auxiliary electric air compressor to air up the bus before leaving a park. HF has a couple small ones on sale and was wondering if these will do the job or should a larger one around 6gal and 150psi be installed?
Airing up tires from the compressor would also be highly desirable.
Thanks
Don
The bus air is about 11CFM recovery. You just need one that is fairly quite and probably won't be as big CFM maybe 3CFM at 80PSI. Belt drives are less noisy but are bigger and take up more room. I just have a Campbell Hausfeld 2 hrp with stacked tanks in front bay. I routed a hose the the rear right side and put a NPT fitting on the pipe below the sign that says "Drain Daily" That large hose comes from the bus compressor head.
So if engine isn't running you start your Genny and or if you are hooked to the pole and run your shop air through the routed hose and a small air dryer( so you don't pump condensation into the Bus lines) into that NPT fitting. Use a double or make one male NPT fitting to connect them both when needed.
What we do is hook the hose up and start the compressor and close the bay door. It takes about 15 minutes and the system is full and we are ready to go. You can also use it to fill tires it just takes a little longer. You will need at least 125PSI to 150PSI is even better.
If you go with HF make sure you ask to run and hear it first because the cheaper ones are general louder especially the oil-less ones.
Dave ;D
These guys have some interesting little dc compressors as well > https://www.hornblasters.com/products/categorytype.php?t=constant-duty-air-compressors (https://www.hornblasters.com/products/categorytype.php?t=constant-duty-air-compressors)
Thanks guys. The bus is outfitted for one already so its all plumbed and ready to go. It had a pancake behind the back right door. Looking on CL and can get a used 6 gal 150psi 2.6 scfm for 50 bucks https://sfbay.craigslist.org/sfc/tls/d/compressor-porter-cable/6258769909.html, better than the HF ones.
The DC units look very nice and compact without the tank but a bit pricey.
Funny ad. I think I'd get rid of the wife and keep the compressor.
Anyway, that one would do the trick, but, you need to mount it in a bay, not in the engine compartment. The moisture will rust it up and seize it in short time. Did that with a small one I had on my bay door latches.
If I was in the area I would buy it and replace the noisy HF unit that I now have. Mine is up front and plumbed into the auxiliary tank just for the suspension, foot rest, and air horns. I have another connection in the engine bay if I want to fill the entire air system, brakes, etc. Although I have a hose to do that, I rarely do. I just want to keep the bus level when parked (Prevost leveler system)
Will
Mine is an oil less compressor of about 1 to 1 1/2 hp. I think it is a Sears. It is plumbed into air system and have a dash switch to turn it on. I don't think the previous owner ever drained the tank as it was 1/2 full of water. Probably has a 12 gallon tank. Pump up the air, start engine and go. If cold, block heater makes instant summertime. Mine is in rear baggage bay between water and waste tanks, so they absorb a lot of the noise. The previous owner spent Winters in Florida and used it primarily for keeping air suspension charged. It's great for emergency tire changes also. Good for chasing air leaks in system without the need to run engine.
Mine has a tankless air compressor that looks like a GAST 6H
Quieter than most that I've heard. Takes about 15 to 20 minutes to air up from nothing in the tanks.
It will provide enough air to make it home if the engine driven compressor fails (or, in my case - if the air dryer purge valve fails).
Won't go past 100 psi, but if I need more, I wake up the big greasy noisy thing in the back. ;D
On my last bus ,I built a super quit compressor. This was done by finding and older non running compressor, brand not important . I replaced the actual compressor pump with a fridge ,(or freezer ) compressor. While it had slow recovery,it would run as needed to keep bus constantly filled. Being a fridge comp., it was virtually silent. Ran about 2 or 3 minutes every half hour.
If you want quiet-here's what I have- the 2hp airless from California Compressor. Be sure to look at the videos http://www.californiaairtools.com/ultra-quiet-oil-free-air-compressors/2-0-hp-air-compressors/cat-4620ac/ (http://www.californiaairtools.com/ultra-quiet-oil-free-air-compressors/2-0-hp-air-compressors/cat-4620ac/) Good Luck, TomC
I bought a 150 psi pancake compressor from harbor freight, cannibalized just the pump, installed in driver compartment, plumbed into the coach air. Works off genset and power pole, not to noisy take about 20 mins to air up, switches at driver seat & compartment were hose connection is.
Going to pick up the used Porter Cable and put it where the A/C was located, the same place as the other one. If moisture becomes an issue, I'll fab some compartment or shield to separate it off. Maybe the last one bit the dust from being in that area.
Quote from: TomC on August 12, 2017, 09:25:24 PM
If you want quiet-here's what I have- the 2hp airless from California Compressor. Be sure to look at the videos http://www.californiaairtools.com/ultra-quiet-oil-free-air-compressors/2-0-hp-air-compressors/cat-4620ac/ (http://www.californiaairtools.com/ultra-quiet-oil-free-air-compressors/2-0-hp-air-compressors/cat-4620ac/) Good Luck, TomC
Tom, this one ? > https://www.amazon.com/California-Air-Tools-SP-9421-Compressor/dp/B00NGK47FK/ (https://www.amazon.com/California-Air-Tools-SP-9421-Compressor/dp/B00NGK47FK/)
Quote from: TomC on August 12, 2017, 09:25:24 PM
If you want quiet-here's what I have- the 2hp airless from California Compressor. Be sure to look at the videos http://www.californiaairtools.com/ultra-quiet-oil-free-air-compressors/2-0-hp-air-compressors/cat-4620ac/ (http://www.californiaairtools.com/ultra-quiet-oil-free-air-compressors/2-0-hp-air-compressors/cat-4620ac/) Good Luck, TomC
I have the 240V version of that double tank California. It is quieter than many other brands, but it has a short duty cycle which means that once it gets hot it will shut off until it cools down. It is made in China, so I don't expect it to last real long. I bought it direct from the company on their website as a "scratch & dent" and saved $100 compared to the prices elsewhere. It had scratches and dents alright from being shipped to someone else and returned, but it works. It is lighter because of aluminum tanks, and one person can pick it up (weighs about 1/2 of a 8D battery), but, while being quieter than others, it still makes noise that would be heard in a campground in the early morning when you are trying to start up discreetly. If you put it in a insulated box, it will definitely need supplemental cooling.
Quote from: windtrader on August 12, 2017, 11:09:52 PM
Going to pick up the used Porter Cable and put it where the A/C was located, the same place as the other one. If moisture becomes an issue, I'll fab some compartment or shield to separate it off. Maybe the last one bit the dust from being in that area.
Maybe. And this one will too! :o
The surprising thing that keeps the California compressor quiet, is having the small 6" long tubes coming off the air cleaners. That really quiets the intake. I don't know of a quieter compressor-except maybe one made from an old refrigerator compressor. Good Luck, TomC
I have a Harbor Fright twin-tank 2HP compressor that's mounted between the frame rails above the front axle (one of the last free spaces under the bus that I can find for it!), and it's fine for occasional use. It can air the entire bus in about fifteen minutes or so, but I usually have it connected only to the accessories system and its three air outlets around the bus. There's a simple self-draining air filter that takes out a surprising amount of moisture from the air before it reaches the accessories tank, and I also installed a valve and air line into the wet tank for airing the entire bus in an emergency. After my debacle earlier this year that required a tow truck, I've put an air inlet fitting on the end of the compressor's drain line next to the front door, making it easy for a tow truck to connect its air to the bus.
The compressor is fairly noisy, but maybe I can quieten it slightly by using 40-weight CF-2 oil in it?! At least it doesn't need a slobber tube.
John
Update. going to rethink what I need for aux air. I've got an older compressor I can stuff in a bay for awhile. Oil unit, nice and quiet. Great conversation and sharing. made me take a pause to do it right for what I need.
What I'm going to do when I get around to it is put an old heavy duty Webster two cylinder compressor head and 1 hp motor in a bay, plumb it to the ping tank so it feeds through the air dryer, control it so it doesn't exceed the governor air pressure, and run the head slow so it's nice and quiet. No tank except the bus tanks. I once set up my little pancake compressor to air up the bus, it went over the governor cut-out and I found it just noisily dumping air on the ground.
The reason for all this is to allow for "quiet" air up before taking off. If the compressor is noisy, maybe not as loud as a 2 stroke bus motor, it's really not addressing the problem. Maybe you don't need a tank at all, just pump into the bus air system. The reason for the tank is reserve capacity and filling up the bus is going to keep the pump going all the time anyway, the tank is doing nothing.
Still might be nice to have the tank and compressor for other tasks. Need to ponder more.
Quote from: windtrader on August 13, 2017, 01:27:53 PM
The reason for all this is to allow for "quiet" air up before taking off. If the compressor is noisy, maybe not as loud as a 2 stroke bus motor, it's really not addressing the problem. Maybe you don't need a tank at all, just pump into the bus air system. The reason for the tank is reserve capacity and filling up the bus is going to keep the pump going all the time anyway, the tank is doing nothing.
Still might be nice to have the tank and compressor for other tasks. Need to ponder more.
Install it in a bay so you can unlatch it, unplug it from the bus air system, and take it where you need air for other things. Sometimes you need air farther away than you have enough hose for.
Aux compressors and their install need to be designed for getting the moisture out.
There's nobody in the lower 48 that can escape a freeze, and the wails of "my bus won't air up" follow right behind.
You have to leave a way to drain the discharge muffler in an MCI, if you choose to add the airline at that point.
Self inflicted wound.
Used to be right up there with Treason, but maybe there's a medal for it now?
Get the water out, keep the water out, drain regularly.
Winter is coming, you've been warned.
happy coaching!
buswarrior
QuoteGet the water out, keep the water out, drain regularly
Are you talking about water from an auxiliary compressor? Water generally collects in the tank. If running the compressor directly into the bus air system, there doesn't seem like there would be an moisture issue. It might be a good idea to have a valve to let the air vent first, then switch it in line once it clears out.
I'm liking the idea a lot since I was about to chuck a very nice but old Craftsman compressor which will fit nicely without the tank.
Don, short answer Nope. Any time you have a device taking in ambient air and basically squeezing it by pressurizing it, it will produce condensation because it heats it up hotter than the outside air it took in originally. That is why most of the buses have air dryers which helps but you still get some water in the systems. You will see when you drain your tanks on the Bus. You have 4 of them. ;D
If you inject air directly from tank-less pump head into the bus through the ping tank, the ping tank will trap the initial water condensate. You can drain the ping tank easily if you keep the valve on it. From there the air goes to the air dryer which will trap the rest of the condensate - the air will be quite cool by the time it gets there and you just need to remember to pump up high enough to cycle the air dryer every once in a while if you aren't running the bus engine enough to do so. Any trace water left gets caught in the wet tank. It's a good system.
Yes, the air drier will take some more moisture, but only up to a point...
First, the coach air system has to be in "loading" configuration, air compressor governor signalling the air drier that the air compressor is going to start pumping, otherwise the purge valve is open, and the input into/through the air drier is closed.
That is usually taken care of by our leaky teakies... the air has leaked off, and it is conveniently and invisibly in "loading" configuration, and it works, but we don't know this is lurking.
Second, the air drier has limits. Somewhere in the dark recesses of my mind.. nope, not sure anymore, (maybe 10 cubic feet?) (and the info is hard to find) there are only so many cubic feet of air you can put through the air drier, and it will be saturated, hence the purge cycle on governor/compressor cut-out.
Here's the scenario: Proud busnut has air drier, doesn't bother draining tanks, cuz nothing comes out anyway. Reads about aux compressors and sets it up to pump in through the "drain daily" plumbing. Doesn't leave facility to "drain daily". Fills the discharge muffler completely with water during the use of the aux compressor and the coach air compressor, no way to empty it. Further, when on the aux compressor for awhile, saturates the air drier with moisture, so damp air is reaching the wet tank, on the aux compressor alone.
Now, the big engine gets started. there is some combination of wet air used to air up the coach to go for a drive. There has been no drying of this build-up air, as the discharge muffler is topped up with water, the air drier is saturated...
The air system reaches cut-out, the air drier has a mighty sneeze, and it is ready for another go. But, the discharge muffler is still full of water, and water has passed to the wet tank.
If the proud busnut continues to ignore the wet tank, because it was always empty... or perhaps worse, relies on automatic drains, or has a cable drain, but doesn't get down on one knee and WATCHES what comes out.... blissfully unaware, the proud busnut heads into the cold weather....
If left unattended, the moisture in the wet tank migrates deeper into the air system, and now there's a mission critical brake valve with a little lick of moisture on the seat... the discharge muffler is full of water, and by association, the copper piping between the compressor and air drier...
Then the cold snap hits.
And there is a screaming post about unable to air up, unable to move, can't release the parking brakes, can't get out of here, I want to move further south... wait, I'm already in Florida/Arizona/California...
There is no where that doesn't see a freeze now and again, in the lower 48.
And all the remedies get trotted out, few of which actually work, and the day warms up just enough... and we think the remedy worked, and we type it again next year for the next newbie.
Keep the water out, get the water out, watch the water leave.
24/7/365
Follow good air system maintenance habits and design, and you will laugh, nervously, when you see the "I'm frozen up" posts in a few short months from now, and enjoy functionality.
happy coaching!
buswarrior
BW,
Embarrassed to say I don't know what to do to clear water from the air system. It was a topic not covered when I got the bus.
What tasks do I need to add to my pre trip checklist, currently I don't check any air system status except for enough air to operate the brakes?
Quote from: windtrader on August 24, 2017, 09:13:39 PM
BW,
Embarrassed to say I don't know what to do to clear water from the air system. It was a topic not covered when I got the bus.
What tasks do I need to add to my pre trip checklist, currently I don't check any air system status except for enough air to operate the brakes?
air system maintenance begins post trip...u drain the tanks.
They make automatic condensate drains you could connect to compressor or coach tank drain port. Just remember it creates another place for a slow air leak down the road.
Be care full with the oil less compressors, you need to check their duty cycle to see at what percentage they run before they crap out or over heat. I bought a Via Air 24v 100% duty cycle to keep my air lock front door aux air tank up. With it running a few times a day it failed just after the 1 yr warranty. When I called Via Air they wanted $45 to look at it plus parts plus shipping to and back. I paid over $200 for this and it failed within a year. Took it apart and it looks like the piston ring wore out and would not compress air any more. I had another oil less by Senco for my little nail gun it also failed the same way. Finally went with an oil filled compressor, still noisy but will probably last longer.
A busnut needs an oil lubed compressor for aux use.
The duty cycle, as noted by others expensive experience, will wear out an oil less unit.
Remember, for space purposes, you can shed the tank part, you already have lots of tanks under the coach, you just need the compressor bits onboard.
windtrader, curb side, engine door, hopefully, there is a drain valve in there, with a sticker "Drain Daily" that needs draining when you use the coach. Do you have an air drier? If so, get some preventive maintenance done on it, fresh desiccant, purge valve heater check. If not, then you need to have a way to drain the wet tank daily, and WATCH what comes out.
A coach is NOT your father's Oldsmobile, it requires regular worrying over, and all will be blessed.
Ignored, the DEVIL gets to play...
happy coaching!
buswarrior
Once I remove the tank it will fit nicely in the engine side bay once housing the AC. Very easy access to tap the air system from there too