I wonder if anybody has any ideas for me. Our coach (DL3) leans when not running. It doesn't instantly lose pressure, just slowly overnight. It then leans to the right. I have checked the usual. Leveling valve – brand new and I even replaced the check valve again to make sure that it wasn't a lemon valve – ,all airbags – brand new –, and I replaced a fitting on the manual un-loaders, that was leaking a tiny bit. I have also sprayed down a lot of the fittings (with soapy water) for the leveling system. I am out of ideas. Is there any bases that I haven't covered? Could it be the fitting on top of the airbag? Am I missing something really obvious? Also, our whole system bleeds down overnight. Which is really strange, because not too long ago it would hold air for quite a while. We didn't do any major work, and I don't hear any leaks?!?! I think that we have a phantom leak (that is all too real...LOL).
Any help would be great!!!
God bless,
John
Interesting, mine does exactly the same thing and it's a Prevost. Always dips to the right, never the left ??? All new bags, no noticeable leaks. I can't wait to hear the replies here ;D I've installed a 2gal AC for when we're parked to keep the level low working, but when I leave it off, overnight it will sag to the right. :(Will
Well not sure if this helps or not but regarding prevost, you might find an extra air bag on the rear duals. On mine there are actually two of them. One of themis hidden inside a compartment that has what I call a trap door right in front of the tags. I didn't know this air bag was in there until a fellow bus nut had his replaced. Not sure if all are like this but it may be something to look for. A hidden air bag!
Ace
With religious perseverance the spray bottle with the soapy water is your route.
With new parts, lots of focus on the connections and the exhausts of the valving.
For the "whole system", do you mean the gauges on the dashboard?
If so, that's the brakes leaking somewhere, or a failed pressure protection valve letting it out your other mystery leak. Do you see zero or somewhere up at 60 lbs in the morning?
I'd be very suspicious of the brake treadle valve, and the relay valve down the back.
Get a soap bubble over the exhausts on these and see if it grows.
A leak free coach is possible, especially a post airbeam, post rad shutters, MCI DL3!!!
Keep working at it, you'll get there!
happy coaching!
buswarrior
Ace,
I thought that was for lifting the tags ??? But maybe I'm looking too far toward the rear. From all the soapy water I've used under this thing, it's gotta be the cleanest rig from the ground side up ;D
Thank you and I'm Sorry for stepping into your thread John. Good luck and keep us posted, Will
PP an air bag is an air bag regardless of what it is intended use is, it still holds air! My point was that it is hidden from view where the other ones you can see from looking in front of or behind the tires. These you cannot see unless you remove the tire and remove the access panel on mine anyway!
Ace
Isn't it great to know your bus is a Republican!! harrr
Okay Ace, I'll bite. You really got me curious. All the times I've crawled around under this thing, I've never seen em. So tomorrow, if the freezing rain and snow abates, I'm going back under. At the least, I should be able to see their hiding place. Thanks again, Will
Well like I said, I have a hidden air bag that I didn't even know was there on my H model. Not sure what or how others are built! Yours may be different!
Ace
Here are things we all must remember:
After all the air leaks are fixed....the automatic air leveler still need the air supply from tank or optional electric compressor to maintain it adjusted level. Why? Because the coach is floating on air. Every time the coach is senses movement while stand still or traveling, it will either exhaust or add air to maintain that adjusted leveling valve linkage. In other words, every time while standing still and whenever the wind is blowing onto coach or getting in & out of coach or just walking around inside of coach will cause the needs of a supply air pressure to maintain it adjusted height. Also if you are park so that one side is lower by 2 inch or more will cause the high side to be more sensitive to bleed and add air.
So every time someone here on the posts about how long it hold air...it all depend on which of the factors of the above paragraph and how big your bus's air reserve tank if it park and no air pumping in the mean time unless you have auxiliary electric air compressor on board.
So the "How long it holds air?" quotes mean nothing to the bus nut.
BTW....the only way to locking air pressure in air bag such as tires do is to added a 3 points leveling system to by pass automatic levelers. Remember air temperature will control air pressure variable....just the tires pressure change from cold to warm to hot.
Our bus nut Pete/RTS Daytona (http://good-times.webshots.com/album/559324954HVWVXC) (left click) (a retired IBM System Engineer) has a system available
Or you can make your own system.
BTW...all coach manufacture's air levelers are 3 points system design to minimize uneven coach's body stresses. MCI's are rear 2 leveler control side tilling and 1 front leveler control the fore & aft tilling only. The other front leveler is for kneeling only. So avoid the 4 points version that is available.
FWIW
Sojourn for Christ, Gerald
Gerald;if all manufactures use a 3 point leveling system how does the low level system work on the H-45 VIP Prevost a friend of mine has one it goes down then levels on each corner and I noticed a J 4500 in Vegas did the same
have a great evening
Gerald, our 4106 uses leveling valves that have a delay of 6 seconds before they pass air. This avoids any air in or out of the bags in any period less than the lean from a normal curve in the road.
As I understand it, no air should be required to keep the coach up if there are no leaks.
Do you know if or which models of bus do not use this kind of delay? I would expect the delays to be used on all coaches for just the reasons that you mentioned.
For what it's worth.
Tom Caffrey
Thanks for the info. It looks like I am back to the old spray bottle. So it doesn't look like I missed anything that I should have seen (besides hosing all of the fittings down). If I have missed something, let me know. I won't be out there today, windchill of -3...and snow. Oh, well.
BTW, the "whole system" means our gauges on our dash. Our duel tanks (well there is four, but it has a primary and secondary tank) bleed down over night, with out being able to hear anything. I will check the brake relay, and treadle.
PP, I don't mind you asking your related question on this thread. If it helps you, ask away ;D.
Thanks for your help.
God bless,
John
Quote from: makemineatwostroke on December 15, 2008, 09:15:39 PM
Gerald;if all manufactures use a 3 point leveling system
They do.
Quote from: makemineatwostroke on December 15, 2008, 09:15:39 PM
how does the low level system work on the H-45 VIP Prevost a friend of mine has one it goes down then levels on each corner and I noticed a J 4500 in Vegas did the same
have a great evening
If it all four corner...that new news for me. If it is, then it has dual leveling system at all 3 points. It can be a newer electronic design "dual or multiple" leveling valve all in one unit. ? ? I haven't seen one yet but nothing is impossible. However, I see no need to remotely lower all 3 points from the manufacture point unless motorhome customer want it equips with independent control lift system for parking on un-leveled ground.
The bottom-line a
four points system is unethical. It will prestress the coach body for no good reason and you can only lift so much so that both front and rear wheels has equal pair of surface contact pressure.
FWIW
Sojourn for Christ, Gerald
Quote from: pvcces on December 15, 2008, 10:55:42 PM
Gerald, our 4106 uses leveling valves that have a delay of 6 seconds before they pass air. This avoids any air in or out of the bags in any period less than the lean from a normal curve in the road.
As I understand it, no air should be required to keep the coach up if there are no leaks.
Do you know if or which models of bus do not use this kind of delay? I would expect the delays to be used on all coaches for just the reasons that you mentioned.
For what it's worth.
Tom Caffrey
Yes, that is correct. All mechanical leveler use Silicone fluid to delay the changes. However, anytime anyone in the coach that moves from front to rear or from side to other is usually more than 6 seconds. And minimum wind at whatever speed alone of 6 seconds or longer, will take air. And if it was repaired with the wrong oil or no oil, then it less than OEM time setting.
I should have added to my first post (I am sorry), to service all three leveling valve after all the leaks are fix.
Thank you for bring the 6 seconds delay.
FWIW
Sojourn for Christ, Gerald
Sojourner My H-45 drops the air from all 8 air bags then levels itself from 4 corners and this the 3rd one I have owned that operated in this way.It does use the 3 point for travel but where is the stress going to be from a frame floating on 8 air bags.Back to John316 the only problems I have had with leaning was because of the check valve or the exhaust valve fwiw
David
Quote from: John316 on December 16, 2008, 05:13:57 AM
BTW, the "whole system" means our gauges on our dash. Our duel tanks (well there is four, but it has a primary and secondary tank) bleed down over night, with out being able to hear anything. I will check the brake relay, and treadle.
John...there is a check valve before each tanks (prim & sec) after wet tank. With engine or air compressor shut off, drain wet tank...till it drained and listen for hissing air still coming out of drain valve. If it is...you have a leaking check valve to one the dual tank.
Rear relay valve have a supply line from one of dual tank and some dual system has no supply line to front relay valve but only when the foot valve after it depressed. So if you hear or see leaks...let us know via posting. We can try to walk you step by step....there is multiple check valve in the circuit as well relay it self to cause the leaks.
If it the foot valve leak from exhaust port...let us know.
FWIW
Sojourn for Christ, Gerald
Quote from: VanTare on December 16, 2008, 07:38:39 AM
Sojourner My H-45 drops the air from all 8 air bags then levels itself from 4 corners and this the 3rd one I have owned that operated in this matter.It does use the 3 point for travel but where is the stress going to be from a frame floating on 8 air bags.Back to John316 the only problems I have had with leaning was because of the check valve or the exhaust valve fwiw
David
The front suspension of H-45 has 2 levelers...one for driving and the other for kneeling. They are both connected to a tee connect to both front sides of dual air bags. So if one of 2 wheels is in a lower point then the other wheel to equal out the pressure via a tee fitting to maintain equal ground contact pressure at all 4 points.
The rears air bags are the only ones to control both the side tilt and the fore/aft tilt. The front air bags are to maintain the adjusted height setting by one leveler valve and only one leveler valve at a time.
MCI's are the same way.
FWIW
Sojourn for Christ, Gerald
Hi, Gerald.
I thought about what you said about the levelers being affected by movement of the coach while sitting.
I think you might be right about that when you first shut down the engine. However, it seems to me that if the body is down by a fairly small amount, the valve will only open to the supply, not the exhaust. If the check valve on the supply side of the valve is good, and the system pressure has dropped, as most do, then no air will flow into or out of the airbags.
This is the only way that it makes sense that a coach could set outside for months without settling down. We have one corner that goes down, but the other two valves keep the air in for nearly three months between uses. I think that the norm is that they are supposed to hold air for a long time.
In this case, the duration of the valve delay has little effect on the loss of air from the airbags.
John, if you can't hear any leaks, you might get a youngster to listen. That can really speed up your search for leaks. Just don't let the youngster go anywhere he might get hurt!
For what it's worth.
Tom Caffrey
Gerald, thanks for your posts, they give me some good places to start.
Tom, I will get somebody else to listen. Thanks.
God bless,
John
Sojourner
I know how my coach leveling system works you flip the switch it goes to a low level postion the on board compressors (2) level from 4 poinits while using the tag also,the coach is equipped with the" BUOY" high and low for the Front and Rear you can let the coach down to clear objects or adjust for high winds.This is all I will say about this topic but it is my coach and I know how it works
David
Gerald and David ,that is the Active Air System made by HWH a 4 point leveling system best on the market so I am told I have a friend with a H3-45 VIP that has that system. It is approved by Prevost, MCI and all RV manufactures so I guess the 3 point only theory is not allways the case good luck
Quote from: Blacksheep on December 15, 2008, 07:32:00 PM
Well like I said, I have a hidden air bag that I didn't even know was there on my H model. Not sure what or how others are built! Yours may be different!
Ace
Good day Ace,
I have come to the conclusion that our buses are different. I just froze my A.. off crawling around on frozen tundra in search of the elusive air bag(s) to no avail :(. I was mainly concerned that I may not have replaced all the bags, but I did ;D. There is a bag in front of each drive and another between the drive and tag. The cylinder (not a bag) is behind the tag and raises and lowers it. I haven't checked any of its fittings for leaks yet-too da.. cold to be playing with water. I'll get back under when the weather warms up. But I doubt if my problem is connected to it, since the air only seems to leave the right-hand bags in the rear. The front and left hold air fine-the front even more so, as the rear will eventually go down over the span of a few weeks while the fronts hold air for ever. I guess that shoots the moving around inside and wind theory all to Heck :D Sorry Gerald, I was really hoping it was something that couldn't be fixed and had to be lived with-got enough other projects going on at this time to be adding to the list ;D Thanks again and stay warm, Will
BTW Ace, my wife read the post and your tag line "Babes, etc", she laughed the whole time I was freezing my arse off for taking you serious ;D ;D