Steve
Forum Replies Created
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I remember when this happened, because my daughter had marched in drum and bugle corps for several years, and I was a volunteer for that drum corps. This accident happened mid-season (4th of July); when my daughter attended the DCI Final competition in August, the rumor mills were swirling and they were wrong. The allegation was that the steer tire had blown, but I looked at camera footage and still photos and both steers were intact. (and P.S. they weren’t made by the company I work for. The tires were not the root cause).
The accident was not investigated by NHTSA and when I was at a bus seminar later in 2018, I asked them why not. The NHTSA official taught me something I didn’t know- they only investigate “high profile” or “multiple fatality” accidents; since there was only one person involved (the driver), there was no NHTSA investigation… unknownst to NHTSA, the young adults involved in drum corps all pointed at the tires. Facebook Fire was crazy within this activity.
My opinion, based on what I know- drum corps are normally a 4 to 5 coach bus caravan, chartered out to the organization with dedicated drivers. The drivers get to know the tour members as family- the majority of the passengers are 15 – 22 year olds, so they are young, enthusiastic and fun athletes. Normally, the buses travel at night, arrive at a high school in the early morning- between 4 am and 6 am. The members sack out on the gym floor and sleep for 4 to 5 hours. The members don’t like the buses to be too far away, because they practically live out of their seat, so the bus drivers will bring an air mattress/ sleeping bag and sometimes, they sleep on site, in a quiet classroom. The members wake up between 7 – 9 am, eat breakfast, practice at the football field for the day and then they “Eat, Pack, and Load”. They leave the high school between 4 and 5 pm and travel to the drum corps competition. The competitions normally run from 6 pm to about 10 pm. Then, the members pack onto the bus, where they laugh/sing songs/but eventually sleep as they trust the bus driver to get them to the next high school- anywhere from 3 to 6 hours away.
Imagine being the bus drivers- I said earlier that “sometimes” they sleep in the classrooms, but sometimes, they will take one bus to a nearby hotel… BUT, that adds cost to the bus contract (hotel rooms), so they may agree to sleep in the high school classrooms… not necessarily restful sleep, but the drivers become “family” and get nicknames like, “Momma Donna”, and they don’t mind doing it. Many bus drivers will ask for this assignment every year, because they get to know the young adults, and they love the marching, the competitions, and the atmosphere.
When this accident happened, the drum corps had a long drive ahea- they were travelling from a California competition to one in Mesa Arizona, and it was a long drive. The drum corps decided to allow the members buses to travel ahead, and the volunteer/staff bus stayed behind to get the competition scores at the final presentation.
This bus accident happened when the bus was travelling alone, at about 4 am. The bus veered off the highway, up a gigantic mesa, and landed on its side (on the other side of the highway). As it was an entertainer bus, there were bunks in it, and all of the passengers were asleep.
The bus driver was not wearing her seat belt, went through the windshield, and died immediately.
There was a parent/volunteer on board, who told her story on Facebook, about waking up to the smell of diesel, being confused/disoriented, and not knowing how to get out. Through the miracles of … higher powers, truck drivers, Prevost safety, luck? … the truck drivers on the highway became first responders. They opened the roof hatches, and used their sleeper bunk mattresses to cushion the fall as the passengers escaped through the hatches.
NHTSA never investigated, but I believe that the driver fell asleep, and sadly, she is not alive to confirm my theory nor to dispute it. And the protocols followed by many drum corps have never been reviewed or challenged by NHTSA for safety. Drivers should be mandated to sleep in hotels and follow Hours of Service guidelines. They should have secondary drivers assigned to these assignments, or shorten the night travel. Buses that travel alone… there should be a designated person that makes sure the driver stays awake. Sadly, it’s an overlooked activity that should be scrutinized. It wasn’t the bus, or the tires’ fault.
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A few of my wires have been changed…does this help?
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Thank you for the replies.
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“We never put a probe on the inlet side of the turbo, if you fry it or break it off for whatever reason the only place it’s going is thru the turbo.“
Pre turbo EGTs are what matter on a hard working diesel engine and post turbo EGT measurements have little or no correlation with pre turbo temps because the temp drop across the turbo depends on a large number of factors.
You’ll fry a diesel engine before you fry a pre turbo EGT sensor. There should be no reason to break off an EGT probe when servicing an engine.
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“Instrument panel picture attached for reference.”
Pyrometer is sub 900F and boost is 30ish PSI. You must be backed out of it at this point ?
Water temp maxed out at 220F ? Where is this temp being measured ? Have you ever looked at what DDEC is measuring ?
Is the TC locked when climbing like this ?
Like I said above, separating the B500 cooling from the engine cooling would do wonders here.
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A couple thoughts here.
First off a larger engine will run cooler than a smaller engine at any given power level because there is more air moving through the engine. So a 14L (non EGR) engine would run cooler than the 12.7. Getting 600HP from a 14L engine is like getting 544HP from a 12.7L engine, all things being equal.
Next, an engine will run cooler at higher RPM than lower RPM for a given power level. Higher RPM = more air flow through the engine = lower temperatures for a given fuel rate (HP). Making 600 HP higher up in the RPM range is quite different than lugging it at peak torque.
And if the Prevosts are like other Allison installations I’m familiar with, the transmission is cooled by a heat exchanger built into the bottom of the engine’s radiator. You can dramatically improve the cooling capacity of the system by adding a separate transmission cooler to the system and not using the radiator’s built in heat exchanger. This will allow both the engine and the transmission to run cooler. However, there can be an issue with the transmission running too cool in some situations. The great thing about the radiator heat exchanger is that the transmission is up to temp when the engine is up to temp. With a separate cooler, that isn’t necessarily the case. I’m not sure how the B500 regulates its temperature. One way around this is to use both an external cooler and the built in heat exchanger, in series.
One way to improve fuel economy, decrease cooling issues and increase power to the ground would be to replace the B500 with an automated manual transmission, such as the Ultrashift. I’ve seen this done before to great effect. Mechanical transmissions have much higher efficiency than automatics, even when the automatics are in lockup.
I wonder if coaches equipped with transmission retarders get a larger radiator that could be swapped in for more cooling. Maybe not though because if the bus is going down hill and using the retarder, the engine load is basically zero and not requiring any cooling.
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Agreed! It’s worrisome for sure.
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Found the screws hiding behind the velcro for the skirt.
Photos of the valve and the screws I adjusted to limit travel as well as a broad overview shot. Am I missing another adjustment?
Thanks
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Jon I found fitting, greased it found follower spun free, too free no grease so I ordered a new bearing 20mm x 52mm double rollers 22.2mm wide
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Thanks very much for the intel…
XLEZ it is!
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Just saw Laura Covington Whites prevost on Facebook. I LOVE THIS!
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Notice how the valances and upper cabinetry do not match the leather chairs, couch and dinette in this 2009 Liberty but they contrast. One is light and one is dark. When its all dark or all light, one flowing into the other it is not as appealing as the contrast IMO. Light furniture might help. There are computer programs than can take your photo and play with different concepts until you find one you like. Best of luck.
Wave
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Someguy you wrote: What are the pitfalls of buying a 1998 versus a newer bus of the same mileage and condition? And also referenced spending $500k on a motorhome.
You don’t have to spend $500K to get a nice Prevost motorhome. We bought a 1999 Liberty XLV in 2014 for a touch over a quarter of that. It had 72,000 miles on it. I don’t think there are major pitfalls in buying a pre-2000 coach. Before I did my Prevost investigation, I thought there would be.
We’ve put some money into it after our purchase. Some planned money immediately because the tires and batteries had aged out, because we didn’t get maintenance records, and because stuff was 15 years old and it won’t last forever.
Then we put some unexpected money in … OTR Carrier A/C compressor died on us, the then 16 y/o original refrigerator died on us, one inverter died (I replaced the then 17 y/o modified sine wave inverters inverters with new full sine wave versions w/more watts), the water heater started to leak (17 y/o), and most recently the radiator was re-cored and the fan clutch was replaced).
Was the money more than I expected, yes … but not astronomical. The coach is tight, leakproof, rides like a dream, and still stunning after 21 years of service. If we decided to head to Alaska tomorrow I’d put on a new set of tires and make a trip to Inland power in Milwaukee for oil and filters changes, chassis service, top off the Freon in the OTR A/C, and put the Detroit Diesel and Allison on the computer to make sure everything was up to snuff (something I’m yet to do and should do).
So what’s the difference between our 21 year old coach and a $500,000 Prevost? A few years, two to four slides (we don’t need no stickin slides to stick and leak), no rivets (did you know rivet coaches rule?), maybe some fancier interior surfaces, the fancy Prevost Multiplex wiring, HD satellite dish, built-in flat screen TVs, maybe a Crestron system, an outside temp gauge and an altimeter.
In ten years what will our then 31 year old coach be like? If I reasonably maintain it and don’t wreck it … it’ll be like a 1989 coach is today. Which still appear to hold reasonable value and for which there is decent demand. But I’ll have a Series 60 engine, six speed Allison World transmission, its a 45′ foot and not 40′, and I’ll have a independent front suspension. It’ll have 275,000 miles and I’ll have put 200,000 of those on it.
(BTW … I firmly belive that 8V92 Prevost motorhomes are probably the best value in all of RVing today!)
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How high is up?
Your question is as specific as that question. An average motor home conversion of 20 to 25 years old is most likely to have under 200,000 miles. It will not have been rode hard and put away wet by drivers who don’t have a penny in them.
The motor home conversion may have some years on it which impacts parts that age, mostly those that depend on rubber like air bags, valves, etc., but it is not going to have miles that wear our not only the rubber parts, but bearings, the chassis structure, all rotating parts, etc. The cycle times on U joints, suspension bushings, tie rod ends, ball joints, etc are going to be far less affected.
Knowing what I know about coaches there is no way in the world I would every think I could breath new life into a high mileage chassis and have a high quality motor home conversion, unless it was based on a low mileage motor home conversion and not a seated coach, executive coach or entertainer.
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Thanks for the advice.
What was the HP rating of the 12.7 in a 1998 H3-45 ?
What are the engine differences to bring it up to the power of the later models ?
What features is a 1998 bus missing that later buses have ?
What are the pitfalls of buying a 1998 versus a newer bus of the same mileage and condition ?