BCM Community

Well today I put an Air Compressor in my bus. It all started when a friend of mine was on his way back home and his H model Prevost bus would not air up and lift off the tires. This would have left him stranded at the restaurant he was at or at least with a costly tow bill but, he had a portable air compressor in his bay. He simply plugged it up and hooked it to his bus air via a factory air chuck and his bus lifted up and away he went, all the way home with his portable air compressor running without any trouble. He then took it in the local shop to find he had a faulty valve (can't remember what it was exactly). He told he me was very glad he had the compressor in his bus and that got me to thinking,  "Hey I have one, why not do the same thing"! So today was the day and it worked out great! I even installed my air hose reel next to the compressor for easy access to the hose. I also have enough hose to go completely around the bus to air tires if needed. This will also come in handy IF I ever need to air the bus early in the morning at a campground which is doubtful since I never want to leave early anyway, if at all!
Another tip he gave me was to install a hose outlet where you connect a hose to access water. just in case you need water in the radiator (during emergency times of course) or to cool off a hot brake or tire. Using cpvc pipe originally, it was easy to splice in just off the shur-flow water pump with a hose connection and a valve. I have enough water hose to reach each corner and then some! Granted, everyone hopes we never need to use these for emergency but, it's better to have them IN the bus just in case than it is to say "I have them at home and WISH I had them now" on a dark Sunday night in the middle of nowhere!

So with all this good information from my friend, I pass this on to you guy's. If you have a compressor your not using, put it in the bus. You just might need it to get home one day and if you can plumb in a water outlet, do it as it makes it very easy to acces water without using jugs or bottles!

Ace

PS Thanks Bill

Your friend is one brave man to drive a bus replacing a 15 cfm compressor with a 2 to 5 cfm and using his brakes, not for me  have a great evening

Stroke before you go getting on your horse let me explain a little further. His regular bus air compressor worked fine. It worked the brakes like normal and raised the rear of the bus like normal. Where the problem occurred was he had a slice or an air line that was rubbing and caused it to have enough of an air leak that supplied air to the FRONT air bags and nothing else which would not allow the FRONT of the bus to lift off the tires. With BOTH compressors running, he was supplying MORE air than was escaping ultimately allowing the bus to raise to normal height and drive SAFELY home! I forgot the faulty valve in question was only found AFTER it was IN the shop and this valve was causing the BUS compressor to run constantly which he said has been that way since he bought the bus!
There was nothing UN safe about what he did to get home. IF he in fact he did NOT have brakes or was relying on a small compressor for braking, HE AND I have enough common sense to leave it where she sits!

You have a wonderful night too!

Ace

Make it clear in your post the way you posted the bus was sitting on the tires with no air and now the compressor was fine till he got to the shop     have a great evening

I posted it correctly! The bus was on the tires! (FRONT TIRES) The compressor was fine! Just not getting enough air to the FRONT bags to lift the bus OFF the front tires due to what was found to be a rubbed air line!

Regardless... having an air compressor as a back up is still a good idea whether you think so or not! I'm sure a lot of other fellows will see that rather than pick the post apart!

I guess this is what one gets for not posting in Off Topic!

What has this board come to?  Geez!

Ace

It is a good idea Ace that is why so many on the board have one in their bus   have a great evening

Ace- if you re read your first post, it looked to me also that his compressor had failed and he was using the electric compressor as a sole air supply.  Two things- need to be a bit more clear and not get so excited when one of us comments on the not so clear post you first made.  I'm glad everything worked out.  I would like to say that the air system on buses are very reliable-but carrying an electric air compressor, if you have room, can always be helpful.  Good Luck, TomC

I see nothing dangerous in using an auxiliary compressor to move a bus if the engine driven compressor fails.  You would obviously know there is an air problem and monitor your air pressure accordingly just as you would monitor more closely any system acting up ie oil pressure, temp, tires ect until you can get service.   If you do not and overuse the air your emergency warning system should activate and warn you of an impending emergency brake system application.

I am not talking about getting on the interstate and trucking down the fast lane without a care in the world or heading out on a trip with a dead compressor but using an auxiliary system to get somewhere for repair.   

So why is it too dangerous to move a bus with an auxiliary compressor?

Don 4107

I would use one to move a bus a short distance but in no way I would drive one and take a gamble on using the brakes over 1 time in that period and the air pressure needs to be at 120 # before I try that plus I don't read where he just moved the bus but drove it all is not clear on this subject to me.I know John Z drove his GM bus to Sonnies place but used 2 electric compressors      good luck

About what Ace first posted was only pertain to the air suspension problem. He never said no air from bus's compressor or failed compressor. Of course, any bus nut would never depend on small compressor after seeing that it took way too much build-up time after applying brake 1 or 2 time before getting on the road. In other word it just common sense that we (including Ace & his friend) all of the bus nut would never drive without sufficient amount of air supply on hand for our safety. I too was a little confuse of his post, but know what he doing because he been driving the bus awhile and still around tell to posts.

About comparing small electric home type compressor to bus's compressor.
Common MCI compressor is 14.5 CFM @ 100psi @ 1250 RPM
Common small home type compressor is .5 (point 5) CFM @ 90psi @ 3450 RPM

In other words, it takes at least 29 times longer to build up than OEM version. So whatever the time it takes to build up after brake applied, will be 29 time longer to in the safer mode.

Air suspension uses much less air supply then braking for each time. So small electric compressor could be good enough to get by til fix and not a major safety factor.

FWIW

Sojourn for Christ, Gerald

What is the air up sequence on a H40 is it different than a H41 and the H45 this is the part confusing me  and Jerry Prevost use the 750 compressor 16.5 cfm   good luck

I guess we need to know how big the auxiliary compressors are that people are using.  Mine is supposedly rated one HP, 2.4 CFM @ 90PSI.  Takes a few minutes to air up if zero air on board.  Never timed it.  I would not want to wait for .5 CFM compressor to air up or do much of anything else.

How big is yours!

Don 4107

   ;D ;D[/font]

    4.5 cfm at 115lbs!!!

I used a small portable twin tank I bought at HF when I lived in SoCal. Used it when I broke down in Palm Springs Dec. '06. I had to move the bus off the off ramp on I-10. It sure did come in handy, but I would not use it to drive very far. A couple of brake applications and you're wishing for more air.

So I installed a snorkel and limped to the nearest sidestreet waiting for the calvary to lend a hand. Thanks Clifford and Sonja!

Paul

BTW, Paul thanks for the article in the latest BCM.

God bless,

John

mma2s, didn't i read you were in Texas?  and Ace, i know you're in Florida.  you boys need to come up to cooler weather.  all that heat causes sensitivity.  we even have snow maybe tonight to really cool heads off  ;) ;).

now Ace, i thought his compressor failed on first reading also.  i didn't think about a "not big enough" or danger until mma2s said something.

course, i don't worry about air bags.  we have the advanced suspension system on Eagles.  when someone says "air bag", i'm usually thinking politician.  :D :D

i carry a 6hp, 120psi, pancake compressor with 50ft of hose.  not sure that will help with the campground leaving early, as if i could get someone up b4 8am, becuase the compressor makes as much noise as the bus!

good idea and the cautionary note was right on.
jm2c, and imho.

Ok I went back and re-read my ORIGINAL post. ONE key word was left out that would have hopefully cleared up everyone's ill thoughts and that word was "FRONT" as in FRONT AIR BAGS!

The bus compressor has been checked out by a pro shop and it worked and is still working great. The problem, again, stemmed from an air line that supplied air to the FRONT air bags on a PREVOST H3-40 which LIFT the bus OFF the front tires and allowed him to drive SAFELY home which was about 1 hour on back roads!

When he arrived home safely, parked the bus, and went to air it up the next morning, the same thing happened. The REAR of the bus lifted, the air gauges (both) said full but the front of the bus never went up keeping him stranded in his own driveway. He again plugged in his portable on board air compressor and THAT supplied the FRONT air bags enough air, along with the bus air compressor together to lift and allow him to drive to the shop which was about 15 minutes on back roads. It seems with BOTH compressors running together at the same time that they supplied more air than was leaking out which kept the bus UP and OFF the steer tires!

Now I'm sure my friend has many more miles than a lot of you since they full timed for the last ten years and that was not camping in one spot and has enough common sense to know what is safe and what is not. Bottom line is, I wasn't aware that EVERYONE had a portable compressor in their bus and thought it was a good idea! Now I know, since 2 stroke informed me that EVERYONE has one, including me!

I hope this has cleared up the negative thoughts that my friend drove an unsafe vehicle down the interstate with just a portable compressor holding the bus up off the tires and working the brakes! I'm positive that IF he had little to no air from the bus compressor, which would not service his needs to drive safely, he would have been towed.

Ace... no snow in Florida but chilly!

Manasst,

Your compressor may make noise but it doesn't feel the air with exhaust.  That's one of the main reasons I carry a compressor.

Quote from: John316 on October 28, 2008, 04:46:51 PM
BTW, Paul thanks for the article in the latest BCM.

God bless,

John

Thanks John, It was long overdue! "Pay It Forward" has become my new slogan.

Paul

well gentlemen! being a greyhound repair shop MANY, many times we have brought hounds back into the shop with just an air compressor. sometimes more than 75 miles...Naturally a small compresssor will not work, but a larger one works just fine. Ours is gasoling powered naturally, just put it in the bay and run the air line. simple....

Hey Ace
I have thought of doing the same. what compressor did you install and what are the specs. have you had a chance to air the bus up with just it and how long did it take for it to build air? just curious how much idling it cuts out in the morning.
thanks
steve

Great suggestions, Ace!!

Might I also add that fellow busnuts should check their coach's air system's schematics in the shop manual before plumbing in an air chuck for use with a portable system, unless the coach already has them.

Reason I mention this is that many coaches have check valves in the system that only allows air to flow one way - usually from the air compressor thru the wet tank, dry tank(s) and finally to the accessory tank. Obviously, if you try to fill the system from the opposite direction, the check valves will not allow you to do so.

If your coach already has the air chucks from the factory, like Ace's does, then this is a moot point. But for those with older models, take a few minutes to find out how your coach is plumbed. In my case, my 4106 actually has chucks both front and rear, so the system can be filled from either end of the vehicle. So do your homework before starting this simple project.

Thanks for sharing, Ace!

FWIW & HTH. . .

;)

I also have a compressor in my bus.

I use it, as suggested, to air up the coach before we leave our house or campgrounds.

Usually as we are within an hour of leaving I turn it on and let it do its thing.  Since its in the bay, I just close the door and you can just hear the hum of it running.

I have used it in a unforeseen emergency once.  I had stopped in a rest area and set the parking brake, I guess at that time a bad parking diaphragm finally let go, it had just enough leaking that I couldn't release the parking brake.  Here's what I did, turned on the portable compressor and let it build to full air capacity, then as I opened the valve to max discharge, my wife pushed in the parking brake and it released.

This of course was not a fix, but we finshed our trip, and did this when we left the campground, weekend salvaged.

When I was home I replaced the defective park diaphragm and the main diaphragm for good measure.

Remember, If you have the tool or part on board, you will never need it!

Cliff