Impact Wrench, Bus Air Question

Scott & Heather · August 18, 2011, 03:22:45 PM

I know this has been discussed before since I've read the archive posts. But it isn't clear enough for a bus newbie. Where can I get air for my impact wrench on the coach? Trying to work on my car, and tried to connect to the air in the back engine bay, but of course when the compressor cuts out, no more air. A pain to say the least. I've read about tying into the front tank beneath the driver, but how and exactly where do I connect my 3/8 air hose? I'm assuming I'll need an adapter for 1/4 lines? A "baby" language description would make my day. Thanks in advance....

Scotty

Iceni John · August 18, 2011, 04:23:26 PM

I have a small twin-tank 2 HP 120V AC compressor that runs off my emergency generator, and have air outlets in three places around the bus. This compressor is connected to the bus's accessories air tank, so when it runs it also fills the acc tank which is about 10 gallons or so. In an emergency I can also connect the 120V AC compressor to the bus's wet tank, enough to release brakes if the engine won't start and I need a tow to get off the road. (I would never, and in fact cannot, run the electric compressor while driving, so it will never be used instead of the Bendix compressor.)

A compressor of this size won't run a big impact wrench too well, but for emergency use, especially if feeding it into a larger reserve tank like I have, it may work with a 1/2" or good 3/4" wrench. I use my compressor for inflating tyres and for running small air tools like my grease gun. For wheel nuts I'll probably buy a 40"-long 1"-drive breaker bar and some Proto impact sockets and extensions.

John

bevans6 · August 18, 2011, 04:59:51 PM

You can put a quick connect on the drain valve fitting on the bottom of your accessory tank in the bay under the driver seat up front. If you don't run the bus up past cut-out on the compressor there will be air at the ping tank valve that you already mentioned. There are places in the engine bay that are part of the accessory system, a small manifold on each forward bay wall, and you can put a QD in there and get accessory system air as well.

Brian

Scott & Heather · August 18, 2011, 06:19:49 PM

Ok....I'll check the accessory tank underneath the drivers' seat. I've already plumbed and connected my pancake compressor to the coach system in the back. So I may take your advice and allow that compressor the 20 minutes it needs to fill up the tanks in the coach air system, then run another hose to my impact wrench. I have a Kobalt 350 ft lbs torque 1/2" gun. I'm assuming it will run fine??? Trying to do an emergency hub assembly/bearing replacement on my Camry before we drive 500 miles for the weekend. The bearing sounds terrible. Thanks for the pointers. I'll see what I can connect...

demodriver · August 18, 2011, 06:24:33 PM

Iceni John,
Is that compressor tank rated for enough psi that its safe for the bus air pressure to build and back feed into it? I have saw a few compressors that have exceeded there limit and its not pertty when the tank blows.

As already mentioned you should be able to tie into any of the tanks and le the bus run to maintain air pressure.

I use my impact off of my bus air to change tires all the time at the races.

Eric

robertglines1 · August 18, 2011, 06:28:43 PM

what about taping into the drain you pictured for the wet tank.

Scott & Heather · August 18, 2011, 06:33:50 PM

QuoteInsert Quote
what about taping into the drain you pictured for the wet tank.

Pressure to it dies when the compressor kicks off.

Tried everything today. And with a shot bearing, and no way to get the old one off, I'm toast. Oh well...I'll figure something out. I always do.

robertglines1 · August 18, 2011, 06:40:51 PM

like they said front left compartment where emergency fill is just put female fitting in there and your good to go.

bevans6 · August 18, 2011, 06:54:31 PM

There is a schrader valve in the front bay marked emergency fill, or similar - it is NOT a supply of air either. The last place I would get air is the wet tank. You'll get it done! They changed wheel bearings before they had air guns...

Brian

buswarrior · August 18, 2011, 07:07:10 PM

And in our excitement to install air fittings for accessory use, remember that you still need a way to drain moisture out of the tank you tap into.

If you put a fitting in where the drain goes, guess where the moisture gets to go when you attach the tool?

Wet tank is a bad place to put an airline fitting, go deeper into the air system for drier air.

Why wouldn't you run the coach engine as a supply of air for the tools? The little compressor is for a quick getaway from the campground.

happy coaching!
buswarrior

Iceni John · August 18, 2011, 08:37:06 PM

Quote from: demodriver on August 18, 2011, 06:24:33 PM
Iceni John,
Is that compressor tank rated for enough psi that its safe for the bus air pressure to build and back feed into it? I have saw a few compressors that have exceeded there limit and its not pertty when the tank blows.

Don't worry, I checked the electric compressor's PSI before I bought it. It's rated at 125 PSI, and its safety valve is really close to tripping at that pressure. One reason I chose it is because its pressure and the bus's are the same. So far so good.

Thanks, John

bevans6 · August 19, 2011, 05:02:23 AM

The bus safety valve will trip before any commercially available compressor will exceed a safe operating pressure. No bets on cobbled together from old propane tank or 50 years old, Dad kept it in the shed, I just put a new furnace fan motor on it compressors.

Air guns and tools in general need both pressure and volume of air to work. If you are connected via a 1/4" hardline 30 feet from a tank, going through a bunch of connectors, an air gun just won't develop enough oomph to do much. I used to have a pony tank that I would carry to the work site, connect to the end of my 100' hose back to my compressor, and the pony tank allowed my air tool to work. Connect your accessory hose directly to a tank if at all possible.

If you are filling your bus system from an external air source via the ping tank chuck, set your air compressor so it stops before it reaches the cut-out setting of your air governor on the bus compressor. If you go over that setting, the governor will cut-out and all the air from the compressor will be discharged via the air dryer vent.

Brian

Scott & Heather · August 19, 2011, 06:25:51 AM

Your replies are saving my skin. I'm headed out there right now to plumb this in. I have tried to get the bolts loose with a breaker bar, but the way it's set up, I can't keep the socket on the bolt head at the right angle while pulling on the bar. So I get twisting slippage. Another few times of it, and the bolt will be round. So my only resort is the impact wrench. Thanks so so much for your help guys. I'll post my results. While I'm out there, maybe you can chime in on how you set up your pancake tanks to run inline with your system. I have a 125PSI tank as well and I'd love to have it filled from bus air and then plumb into it...nice concept. Anyway, still learning. Thanks again so much!

Scott & Heather · August 19, 2011, 08:32:47 AM

Alrighty...so there's no air at that front schrader fitting. Nada...not sure where to tap in now. Buswarrior, I'm running the coach fast idle while I use the impact. Just want to get access to my coach air without it cutting out in between my Bendix compressor cycles. Not sure why there isn't air to my under driver schrader. But I've seen stranger things...

thomasinnv · August 19, 2011, 08:43:30 AM

If the schrader is on the bottom of the tank it is probably just plugged. Pull the schrader and clean it out. Probably lots of junk on top of it.