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Sudden Bus Leans
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Was Jon yelling?:)
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Yup……but now I feel alot better when I see my air guages at zero…………LOL
I do get confused though…….some people have said their air guages don’t move after a month or more of storage. Do they store the coach with the level low on and the auxilliary air compressor running? How much loss of air is caused because it gets down to 30 degrees at night?
I see my auxilliary air guage fluctuate when I drive between 110-120 psi……the front and rear guages barely move when I drive. Does this mean I have a bad leak somewhere? Jeff used some ultrasonic thingy with headphones and went all around, under and inside my coach and couldn’t detect any leaks other than the step cover which he is fixing next week. If he couldn’t find any air leaks with that piece of equipment I feel like I’m peeing into the wind soaping up everything looking for a bubble. I also get Jon’s point that every converter may do things a bit different but believe me guys my Royale has very very few converter items that run on air.
On my last 6 coaches (none prevost) the air guages did the same. My Dynamax auxilliary air cycled about every 3-5 minutes…meaning the guage would go down to 110 then back up to 120. Took it to the freighliner factory in Gaffney and after a test drive and inspection they said this is normal for my truck conversion. I remember the tech saying “don’t you hear air released on big rigs driving down the road?”
I’m just saying that those of us who don’t have the facility or the time to hunt these darn things down it can be frustrating. Peter gave me some great advice a few weeks back……he said keep trying to find the air leaks and have them fixed when you do but just drive the damn thing it’s built like a tank! The best tool in my toolbox is my checkbook and I’m not afraid to use it but these darn air leaks are a bit intimidating for us “newbies” to the prevost world.
BTW……if anyone wants to meet me at Jeff’s next wednesday I would love to have help understanding my air system. If your in Florida and want to visit St. Augustine, I’ll pay for an ocean front site for the weekend if you want to take me to school…..
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WHOOOHAAA
The cap come off the top.
LMAF
Later
bv
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Jim,
Don’t let Jeff fool ya with that ultra air thingy he straps on and walks around the bus, it’s actually a top secret money sniffer and he’s checking for cash inside your bus, but you think he’s checking the outside. Just watch Josh when he’s doing that, he’ll have a spray bottle of soapy water following his dad and grinning.
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Jim , Trina and I are going to be in your neck of the woods this winter I will stop over and help you.
When I had my Royale I would park it in road mode aux comp off and all three gauges would stay for months and bus would not lean , do not know about this liberty yet we will see I am going to replace all air related items this winter, fittings too
Easy big Jon !!!!!!!
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Cris, have had my coach in Prevost Fort Worth and Houston chasing lean problems and spent several thousand dollars. Have had all bags, several vavles, including Ride height vavles and fitting replaced at there discretion with Card Blanche. Still goes down in about a week in summer and last winter quicker because of the cold. When I get ready to fix the problem gonna take all my tickets/invoices from Prevost and let Jeff have a go at it. Still use them for service as I can get under and look at bottom of coach.
PS,
For the new opening last year and on there website (Houston) my coach was the one on the left in service bay .
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just Map Quested the trip to Jeff’s place and it is 12.5 hours from here but I have to drive straight thru Nashville.
I haven’t spent much time in Nashville. I really appreciate the input here. I keep reading about Jeff’s work on PC. Wish it was closer but suppose it will be worth the trip.
I will reach out to him soon to schedule a trip out there later this winter.
Thanks again.
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Crisis 12.5 hours is not that far because if you have to take back to Prevost a second time you will have that much time in it. TAKE IT TO JEFF’S you won’t have to go back to have anything redone , I drive a lot of miles every week , it’s worth it to only do it once and right , I do a lot of my own work in the winter but when on the road from March to November I take it to Jeff’s and sometimes Prevost but I watch them like a hawk. There are just a few places to check when it leans air bags , norgrens and valves, fittings ,if it does not have auto leveling going on when parked , if it does some other things to check
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Chris, get quotes. You will find the extra driving distance will be one of the best decisions you can make. If you don’t find the savings in the thousands I will be surprised.
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Peter,
I would love the help from a past Royale owner………my cell # is 989-335-0435 and we will be in St. Augustine from November 10 thru April 15 for the most part taking trips to other destinations once a month for a few days but that will be home base. If you haven’t been to St. Augustine it is FABULOUS. Your site and dinner is on me if you do come just give me about a weeks notice to get you a nice site on the beach.
In reality, I think I am very close to getting a leak free coach and after my trip to Jeff’s things should work out great. My wife hates sitting anywhere for service so I”m going to have to make Jeff’s a “fun” trip for her so I can get a day or two for him to do his magic. I had to promise her a white water rafting trip in Sieverville after we leave Jeff’s and looking at the weather it may be a bit chilly doing that but it is the price I’ll have to pay.
Tom, I KNEW that little thingy had something to do with money….I think it is a “cash flow” meter and yes, Josh did have the soap bottle as well. I did feel pretty darn good after leaving Jeff’s and after he inspected my coach. He said the underside looked great and he really didn’t find many air leaks at all.
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It is pretty important for every one driving coaches to understand the pneumatic systems. We are all driving the equivalent of a large commercial vehicle and except for motorhome drivers, everybody else is required to have a license that proves they are qualified to drive one. Part of the requirements to obtain a license (a Class B) is an understanding of the pneumatic system. If you don’t understand the systems, and don’t know how to do a pre-trip inspection of the system you are not qualified to drive such vehicles. No state will issue a Class B license unless you demonstrate that understanding.
At the very least, and for your own safety learn the basics of our coach air systems. They may seem complex and daunting, but when you study how the systems work you will see how they work, how they are set up to keep you safe in the event of a failure, and how you can interpret what the pre-trip test is telling you.
One of the most important things to understand is that the pair of brake system gauges on the dash are only for the brake systems and have nothing to do with the suspensions or other air operated accessories including those installed by the converter. If you have a total catastrophic failure of the aux system, such as a failed air bag or defective valve your protection valves between the brake systems and the aux systems will maintain about 75 PSI in the braking systems which is more than adequate to maintain full braking functions.
If the brake system pressures are holding steady, and the aux pressure gauge (if the coach is equipped with one) is flickering as Jim describes it is not likely the system is losing pressure and being refilled. If I had to guess the problem I would look at the gauge first to see if it has a problem. Some coaches were equipped with electronic air pressure gauges and it was not uncommon to see them dance a little.
The typical coach has a 120 PSI compressor cut out, and 100 PSI cut in so a variation between 110 and 120 on an aux gauge is unlikely to be an indicator that the pump is cycling. Having said that, keep in mind converters modify the aux system by adding components and an aux compressor. If the system is in fact dropping pressure as indicated by the gauge, the aux compressor could be cycling on and off. A leak large enough to make the gauge fluctuate as described should be easy to detect.
FWIW, once a coach is leveled the automatic leveling system should be turned off. Wind and people walking around inside the coach create enough movement to cause the automatic system to constantly exercise to try to keep the coach level. Running an aux compressor every 30 minutes is a good indicator something is not right. In fact that is a big leak.
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Jon,
In another life I had a CDL-A when I drove a truck for 7-up……I understand how the systems work on a semi-truck and did hundreds of pre-delivery inspections before going on the road. Remember on a truck you have air for the brakes, the drivers seat and the trailer…that’s about it.
That being said, my questions don’t arise when the coach is moving but when it is sitting still. Since the front and rear brake guages are always at 120 and the aux bounces a bit I don’t think there is any real issues with the air system. I’ve replaced ALL the major air components and have had it at Prevost twice and Jeff’s once looking for any potential leaks…..each time one or two “suspect” valves have been replaced but no major leaks found. Since the coach “kneels” in the front after 3-5 days of being parked I’m losing air somewhere. If I keep the leveling system on, the coach will stay level for extended periods. While in Florida last year I only tweaked the level once in 2 months.
When I picked up the coach from Legacy last year Brandon told me to put the coach in “level low” mode prior to leveling the coach. In reading my HWH manual, it doesn’t say anything about putting it in level low at any time before, during or after the coach is leveled so I question wether that is the correct procedure. I’ve done it both ways…put it in level low and not putting it in level low. I know all the coaches are different but how do you guys do it when leveling. I opted to follow the HWH manual which is pretty simple.
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I never use auto level , I put switch in manual mode push up or down on the side I need push each of the three switchs back to neutral leave manual switch in manual , shut coach off, when I start coach I put switch back to road level low light will be on until I do that when engine is running , wait for coach to go back to road height and air to build up
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I’ve used auto level on occasion but I feel doing it manually gets me closer to true level. So for you Peter, you leave it in level low while parked and leave the HWH on “manual” before you shut down the coach then back to road height when you leave…..When I’ve done it that way, the coach stays level for extended periods and the HWH compressor in the front bay rarely turns on.
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I know what Peter is saying because I understand how Liberty set their up. With Peter’s coach when the key is off the entire suspension system is “locked”. He levels the coach with the coach running, and at that point he can return the switches that control the front, left rear or right rear to the neutral position or he can just turn off the key. As soon as the key is off whatever air is in the air bags is then locked in the air bags (assuming no leaks).
The Level low I am guessing is set up the same way, in that as soon as the key is off whatever air is in the air bags is locked in. Where there is a question is when the converter installed the HWH system. I do know some HWH systems are always working in the background with the key off to maintain a level coach. Some as described above apparently can be set in a manual position and nothing happens until the system is controlled to go up or down. What I do not know is if the HWH operates with the key off.
As to understanding the brake systems I cannot stress how mportant that is. I will not reveal any names or even describe the coach, but I was once asked to answer some questions about a coach air system. As it turns out the coach in question took forever to air up. And when it did I walked the owner through a brake system check. Upon application of the service brake the needles headed south in a hurry. Then it again took forever to air up. I warned the owner he had a serious issue and it needed to be fixed ASAP.
He later told me he had to make a hard stop in a construction zone and nearly rear ended a cop at the beginning of the construction zone. My point is he had been driving his coach like that for quite a while before we did the systems check and just was lucky. He did get the brakes repaired after that. He did not understand enough of the system to determine if the system was working as it should. Just because a coach does air up, it does not mean the brakes are OK or are going to work. And to repeat, the aux air system and the suspensions have nothing to do with the brake systems other than they use air.
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