Author Topic: electric air compressor tied into air system on bus  (Read 34611 times)

Offline thomasinnv

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Re: electric air compressor tied into air system on bus
« Reply #30 on: August 28, 2010, 06:58:35 AM »
this taken from DOT standard 121, air brake systems for trucks and buses....

S5.1.1 Air compressor. An air compressor of sufficient capacity to increase air pressure in the supply and service reservoirs from 85 psi to 100 psi when the engine is operating at the vehicle manufacturer’s maximum recommended r.p.m. within a time, in seconds, determined by the quotient (Actual reservoir capacity×25)/Required reservoir capacity.

i see no mention of it HAVING to be the onboard oem compressor.  as long as the 'temporary' compressor can supply 'x' cfm in 'y' amount of time i don't see where any laws were broken.
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Offline BG6

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Re: electric air compressor tied into air system on bus
« Reply #31 on: August 28, 2010, 08:16:56 AM »
i see no mention of it HAVING to be the onboard oem compressor.  as long as the 'temporary' compressor can supply 'x' cfm in 'y' amount of time i don't see where any laws were broken.

That list assumes DOT-approved standard equipment.  Non-approved equipment doesn't satisfy the requirement.

Look at the lenses on your ack lights.  See where they say "DOT" on them?  A non-DOT lens, even if it meets all standards for color and size, does not satisfy the legal requirements.  In 1967, they grandfathered most prior equipment and configurations, but not air and braking systems -- since January 1968, non-approved equipment "doesn't exist" under the law. 

It doesn't matter if your 1967-vintage coach had a compressor operated by a hamster running in a wire wheel, since 1968 you have to run a compressor which is DOT-approved if you are going to run on the public roads.

Even though we don't have to get DOT inspections on a private coach, it is against the law even for us to operate a coach which can't pass that inspection.  If his kludge had been discovered, the coach would have been towed to an impound yard and the trooper would have issued a citation for reckless operation of an unsafe motor vehicle in excess of 26,001 lbs.

We're not talking about a cracked windshield or a loose fender.  We are talking about the single most important device in the coach.

Offline BG6

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Re: electric air compressor tied into air system on bus
« Reply #32 on: August 28, 2010, 08:30:18 AM »
OK 1st off personally as long as Merlin had air pressure and kept a vigilant eye on the gauges, I see nothing wrong with using the auxiliary compressor to get off the road.

"Get off the road" implies "at first safe opportunity" -- that is, running from a rest area to the nearest shop or safe long-term parking.  I would agree with that.  If he had said he hooked up his Chicom compressor to get from the rest area to the shop ten miles down the road, I would have congratulated him for his initiative.

Unfortunately, that was not the situation.

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And yes it took a little time to get the replacement compressor from MN. not 6 weeks, but not the next day either. (thanks Craig! ;))

You were buying a new one, right?

Yesterday I checked six truck places for a compressor for my coach.  Two had no clue what a 6V92T is, but one of THOSE had the compressor on the shelf new, two rebuilt, and the other could get it overnight if I ordered by 2PM.  Three of the four that knew my engine had the compressor, and the other gave me the name of two wrecking yards that were likely to have one and suggested that Freightliner in Salt Lake City would probably have a shelf full of them (he was wrong, they only have five).

If I upchucked the compressor shaft this morning (Saturday), I would be on the road again by Tuesday afternoon.

That's not calling Ted or Luke -- in each case I was calling the nearest places I could find online, in rural northern Nevada. 

Offline BG6

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Re: electric air compressor tied into air system on bus
« Reply #33 on: August 28, 2010, 08:46:17 AM »
Some vehicles are operating in worse condition I'm sure.

And you're OKAY with that . . ?

Try this one -- your wife and kids are in the Toyota on the highway just ahead of Merlin's coach and the Harbor Freight compressor that he's been using for 1100 miles.   This idea works for you?

Offline BG6

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Re: electric air compressor tied into air system on bus
« Reply #34 on: August 28, 2010, 08:55:47 AM »
Ah, a hot topic.  Nice.

So, first I'd like to share that if it were me, my first choice would be to make all attempts at the proper repair before attempting an alternative repair.  Since I don't fulltime, it is acceptable for me to have the bus towed to a facility where it can sit while parts arrive - but what if those parts were never again available? Do I scrap the bus in place? 

There are very few coach parts which are "never again available" -- some parts are EXPENSIVE, but just about everything is available to fix a coach which you would put on the road again.   However, if it won't pass a DOT inspection, you don't put it on the road, except to take it directly to the point of repair.

In this case, we are talking about a readily-available part on a coach with a driver who wanted to get to his vacation home.

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Re: electric air compressor tied into air system on bus
« Reply #35 on: August 28, 2010, 09:19:58 AM »
So - how long is this crap going to go on?

there I said it >:(

Offline Eagle

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Re: electric air compressor tied into air system on bus
« Reply #36 on: August 28, 2010, 09:35:26 AM »
So - how long is this crap going to go on?

X2

Offline BG6

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Re: electric air compressor tied into air system on bus
« Reply #37 on: August 28, 2010, 09:43:25 AM »
  so, air is necessary to allow the vehicle to move...loose too much air and the vehicle will come to a stop.  do i have this right so far? 

NO, and someone may DIE because you don't understand this, so pay attention.

Lose air and you get an uncommanded and uncontrollable application of the DRIVE AXLE brakes.  If you are going slow and on the flat, they will lock the drive wheels.  If you are on a downgrade or at highway speed, they will slow you until they overheat, at which point you have NO brakes on ANY axle.

You have NO braking on the front axle (or tag, if so equipped), meaning that you have -- at best -- ONLY 30% OF YOUR BRAKES, and that assumes a speed below 40 MPH, even weight distribution on all axles, good traction on level ground.

Why do you think they have runwaway truck ramps on downgrades?

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if i have a tire blow out on the interstate would i be expected to have the bus towed to a tire shop to have a new tire installed?

No, you would be expected to call for a road service truck, or drive slowly to the nearest tire shop and hope a trooper doesn't decide to cite you for operating a vehicle in an unsafe condition (usually they won't, if you aren't causing a problem or hazard for other drivers).

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  would it be considered 'irresponsible' to put the spare on and drive to the tire shop if the spare was not the exact same tire as the one that blew?  before anyone jumps on the band wagon over that last comment...literally thousands of cars are produced with spare tires that are not the same as the regular drive tires.  thought i would throw that in there.

Let me throw in here that those "donut" spares are specifically designed for a single use and are marked "Max speed 50MPH" . . .however, you are talking about emergency operation to a point of repair, which makes it a judgment call by the trooper or the court.

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ok, so i guess maybe i am saying i don't see the big problem with what he did.  can't say that i would have went 1200 miles that way, but i don't see where the danger was in what he did.  how is what he did any more dangerous than running with the oem compressor?

The OEM compressor was designed to put out 15 cfm at 150 PSI with a 100% duty cycle (DOT minimum standard).  The Harbor Freight compressor is SUPPOSED to put out 4 cfm at 90 psi with a 30% duty cycle -- and they have a 10% infant mortality rate (where they die within the initial warranty period), so maybe they thing doesn't even meet that low standard.

900 cubic feet per hour at 150 psi (certified) or 76 cubic feet per hour at 90 psi (maybe).  NOW do you see a problem . . ?

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i would also be interested to see the dot regulation that states it is illegal to drive with a temporary air supply.  not saying it don't believe there is one because i am sure there is...i am just curious as to how it is written.

Is THIS your card . . ?  From 49 Code of Federal Regulations 571.121:

S5.1.1 Air compressor. An air compressor of sufficient capacity to increase air pressure in the supply and service reservoirs from 85 psi to 100 psi when the engine is operating at the vehicle manufacturer’s maximum recommended r.p.m. within a time, in seconds, determined by the quotient (Actual reservoir capacity×25)/Required reservoir capacity.

S5.1.1.1 Air compressor cut-in pressure. The air compressor governor cut-in pressure for each bus shall be 85 p.s.i. or greater. The air compressor governor cut-in pressure for each truck shall be 100 p.s.i. or greater.



Offline Paladin

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Re: electric air compressor tied into air system on bus
« Reply #38 on: August 28, 2010, 09:51:00 AM »
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Offline BG6

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Re: electric air compressor tied into air system on bus
« Reply #39 on: August 28, 2010, 09:52:11 AM »
So - how long is this crap going to go on?

there I said it >:(

Until even the most nugget newbie here understands the danger that a bad air system poses, I guess, and is no longer willing to give a pass to the guy who risked all those lives for 1200 miles.

Or maybe until I can read this thread without seeing the young wife of a friend of mine, who was here in Nevada just two weeks ago but will never be back, because the brakes failed on the bus she was in.


Offline luvrbus

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Re: electric air compressor tied into air system on bus
« Reply #40 on: August 28, 2010, 10:20:37 AM »
Man all this BS comes from a guy asking a simple question , who was the guy here that drove from MN to TX with a electric compressor before he found somebody to repair it I never read where he left a string of accidents in his travels,people do what they gotta do
Keep all the DOT stuff out of it I doubt if 90% of the buses here would pass one take a 150 bucks or so and see
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Offline zubzub

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Re: electric air compressor tied into air system on bus
« Reply #41 on: August 28, 2010, 10:42:35 AM »
Man all this BS comes from a guy asking a simple question , who was the guy here that drove from MN to TX with a electric compressor before he found somebody to repair it I never read where he left a string of accidents in his travels,people do what they gotta do
Keep all the DOT stuff out of it I doubt if 90% of the buses here would pass one take a 150 bucks or so and see

X2

Offline Paladin

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Re: electric air compressor tied into air system on bus
« Reply #42 on: August 28, 2010, 10:47:45 AM »
I've never placed anyone on my ignore list before but I think I'm finding a new use for that list.

Personally I get tired of people using the forum for beating others over the head with their personal crusades refusing to leave things alone until everyone is beaten and squelched (controlled) into meek submission. It really detracts from the overall intent and purpose of the forum. This is how we lose members folks!  

Point made, some will agree and others, apparently many won't or will see abuse in the presentation and a bulldogged refusal to leave things alone. I hope I see a lock coming in here soon.

Next topic?
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Offline Jriddle

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Re: electric air compressor tied into air system on bus
« Reply #43 on: August 28, 2010, 10:49:22 AM »
Some vehicles are operating in worse condition I'm sure.

And you're OKAY with that . . ?

Try this one -- your wife and kids are in the Toyota on the highway just ahead of Merlin's coach and the Harbor Freight compressor that he's been using for 1100 miles.   This idea works for you?

I don't think everyone here is giving anyone a pass to run without an OEM compressor. I think most are saying it is over and done with and that is what he did. I didn't say I would go 1200 or 1100 miles this way. I said I would try it to get off the road. I am sorry about your friend but you can't blame this BUSNUT for that!!!!!!!
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Offline steve wardwell

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Re: electric air compressor tied into air system on bus
« Reply #44 on: August 28, 2010, 10:54:37 AM »
Girls ! lets all be nice now and give it a Zzzzzzzzzzzzzzzzz
Sometimes the more I think about something the less I think about something.    As soon as I save a little money my bus finds out.                                      Why grab a plane when you can take the bus ?                         If I'm wrong 10% of the time how can the "Queen" be right 100%

 

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