BCM Community

Hi all,

Finally have my hardware to build my airbag leveling system.  I was wondering what you all recommend for type and size of tubing to run to each corner?  I have an MC5A

Thanks

--Mike

   Mine used 1/4 inch dot. tubing. One of the original "Level It" systems.

On that note, someone mentioned earlier that we might not really need the leveling valves on a coach because we aren't loading weight on and off.  This interests me as there would seem to be less to worry about if they were removed.  Thoughts? 

I think it's correct that our use doesn't really call for leveling valves for the reason you point out - our load is relatively stable and unchanging.  I do think that the leveling valves as stock are a simple and highly reliable system, but replacing them with control valves is likely to be equally simple and reliable.  I would stay with the tripod system of interconnecting the front so they are up and down only, and using the rears for height and side-to-side leveling.

Brian

I read that also and am now going to buy the gauges, and valves so when I replace my front bags next spring, I can eliminate the factory valves (2 of which I just put on the back).  Makes sense why they're there in the first place and why we don't need them now.

Possibly but I prefer having the ride height valve in place to keep the bus at the correct ride height through temperature changes, fuel level full to low, different amounts of gear on board, minor air leaks, etc. I know can manually adjust the pressure per corner or end and check the ride height but I will keep the automatic system.  

I used 1/4" DOT air line when I rebuilt the air bags and level valves on my 4106.

I don't think the level valves are necessarily needed, but running air lines to a remote air pressure regulator so the air pressure to the bag can be adjusted sounds like a lot of work and certainly wouldn't save any money.  But, it would be really nice to raise and lower the coach as needed, as well as help level it out when parked.

I kept the automatic leveling valves, but have the capability to switch to manually operated by switches and solenoids. I like the system-don't have to think about it when driving.
You should keep the 3 valve system-one in front and two for the rear to keep from twisting the bus. Good Luck, TomC

That is my plan as well. I have 3 solenoids that I am going to be putting inline with the bag lines so that I can bleed air off of when parked if I want to.

Quotewhy we don't need them now.

I think you do. Go from full to empty fuel and or full to empty water and or full to empty waste tanks and there can easily be a ton or more of weight moving from front to back and side to side and that isn't trivial.

Where does this fear of failure of height valves come from. Probably one of the most reliable systems on the whole vehicle, possibly because to a certain extent it is leak tolerant. Get rid of it and I'd say you will be driving with a list more often than you would like.

Given that most "normal" large motorhomes do have levelling valves, wouldn't you think there might be a good reason.

I used 1/4" DOT Vinyl lines to each corner and a supply from the supply tank to the air control valve. 4 Paddle switches and 2 gauges with 2 needle arms on each gauge. So I can adjust and have any corner or all at once which ever i choose too. Has effected anything other than leveling at campsites without having to use my blocks and if going down the road and my levels show out and i can feel it I just reach next to my seat and push a valve to adjust. Most of the time I set them before I leave and never have to adjust them unless we stop at a campsite for the night and it is not level. I left the leveling valves in but disconnect them long ago.

Dave5Cs

www.hwh.com (http://www.hwh.com) so many different ways to do a air leveling system you can find the schematics for about all on their site

Quote from: luvrbus on November 13, 2014, 05:52:07 AMwww.hwh.com (http://www.hwh.com) so many different ways to do a air leveling system you can find the schematics for about all on their site 

   Thanks, Clifford.  That website is very useful.

Quote from: mung on November 12, 2014, 07:52:22 AM
On that note, someone mentioned earlier that we might not really need the leveling valves on a coach because we aren't loading weight on and off.  This interests me as there would seem to be less to worry about if they were removed.  Thoughts?  

It is true they don't serve a useful purpose in a conversion as they are originally designed for passengers and cargo, but they do offer a real opportunity to serve as the basis for a manual leveling system for parking.

If removed you would still need some system for keeping the bags inflated. They do/will leak!!

people thinking they are going to twist bus with 4 valves need to draw a sketch  and think hard. if you still think 3 is better probably shouldn't own a bus or give other people advice

Coach Services , Gary you still making and selling the kits ?

Yes Clifford:  Have all the old parts & skill to make them but I am retired/tired.

Mine has 3 height valves as original equipment. I figure GM had a good engineering reason why they didn't use 4.

However, with 4 corner control & an axle hook, you wouldn't need a jack to change a tire.  ;D

I have had both still have a 3 point leveling system to me  the 4 corner( Bi Axis) is a far superior system

I guess I'm too dense to see it for myself, so could you please explain how the 4 is a better system?

I can't seem to get past the fact that a 3 leg stool doesn't rock, but a 4 leg stool, if not on a perfect floor, will leave one hanging. . . .

I had a HWH 4 point hydraulic system on the Eagle solid as a rock I now have a 3 point RVS hydraulic system on the motor home there is always a little movement in the front with the single jack mounted on the front, the rear is solid with the 2 jacks that is what I go by

Kyle   drive you little convertible down a crooked road.  then ride a three wheel motorcycle down the same road.

that is the difference in the stability of levelers also.

uncle ned

Air bags will be bouncy, regardless of how many valves you have on them. 

Hydraulic cylinders will be rock solid, since hydraulic fluid doesn't compress.
I would think the bounce from a 3 hyd cyl setup is the frame flexing/ twisting. I'm guessing with air bags, it would be difficult to distinguish the difference in vehicle flex & air bag bounce.

I do agree that a 4 point system with hydraulic cylinders can have less bounce or movement. However, with air bags, it won't matter how many valves one uses - air still compresses.

Regarding frame twist with air bags, if it makes that big a difference, maybe you should get a better chassis to start with.  :o

As for the drive on a crooked road - I do remember some from the vehicle dynamics classes & what happens if a wheel lifts off the road.

About a 3 wheeled motorcycle - nope, ain't gonna ride one of those. I can barely control a car with 4 wheels, I don't stand a chance with 3 !  ;D

If I were doing a hyd leveling system, it would have 4 cylinders, 2 height valves at the rear & 1 at the front. Once leveled, the front cylinders would then be isolated from each other. Seems like a good idea to me anyways. . . . .

      I'm looking at doing one of these systems, but so far it's all theory and I've only been listening to what people say.  Thanks for the info, Gary -- I'm not sure I know enough to think outside the box but you're certainly made my box for thinking bigger.
      Considering this discussion, maybe it's that three point is "idiot proof" (but doesn't support the bus well) and four point requires care to correctly get the frame supported at four points but once it's set and is properly lifting the four points in correct balance, the support is more solid?

Has anybody thought of using these:

8 Ton Long Ram Air/Hydraulic Jack
http://www.harborfreight.com/8-ton-long-ram-air-hydraulic-jack-94562.html (http://www.harborfreight.com/8-ton-long-ram-air-hydraulic-jack-94562.html)

16,000lbs capacity
air operated, manual backup
17.5" stroke
35.7lbs

It would need a large retracting spring, like this:

National Hardware 7688 Garage Door Extension Spring with Safety Cable
http://www.amazon.com/National-Hardware-Extension-25-Inch-110-Pound/dp/B000B4N0SO/ref=sr_1_1?ie=UTF8&qid=1415974854&sr=8-1&keywords=garage+door+spring (http://www.amazon.com/National-Hardware-Extension-25-Inch-110-Pound/dp/B000B4N0SO/ref=sr_1_1?ie=UTF8&qid=1415974854&sr=8-1&keywords=garage+door+spring)

Both mounting points on the jack are pivots, so they can't be mounted like "normal" RV leveling jacks (straight up and down, without bracing).  They need to mount similar to backhoe outriggers- see the first picture below.  On a bus, I would mount the ram nearly vertical and mount the outrigger pivot near the differential- see second picture below.

(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FQ7U8fZa.jpg&hash=a0d803c8e37dc9ecfb89b19859b27305c4844acf)

(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FqOygbcc.jpg&hash=3b311aea56d3725d4cb23063e4dcfbde5b8dd159)

I do not know how the professional leveling systems deal with hydraulic "bleed down".  There must be some sort of locking system that I am not seeing.  I am not sure how to lock outriggers in place.  There is probably a simple way to do it that I am not thinking of.

It wouldn't be a fully automatic leveling system, but it would be an effortless way to level a bus without spending $4000+ on a leveling system.

The HWH mounted on the Eagle were on a angle like 12 inches over center when extended lol the 4000 bucks is for the Big Foot leveling system, Jesse the HWH 64,000 lbs I had installed cost a little more lol almost double.

You being a Eagle owner I am sure you know this but the 4 corner air leveling system (not 3) was a option on the motor home chassis from Eagle, I have the schematics and parts list in my model 15 manual if you want a set

 :o NOPE! 100X nope! I would live life tilted a few degrees sideways and save the $8000 for a rebuilt engine.  My experiment will cost no more than $500 in materials.  That is about as much as I will pay for a level bus.  ;D

Edit: I have actually considered adding air bags to my Eagle just for leveling.  The air bags and hookups aren't too expensive... and in 10 to 20 years I will need them when the Torsilastic suspension runs out of adjustment rod.  The hardest part about putting air bags on an Eagle is designing strong enough mounts.  There are some guides on Eagles International that I have been looking at.

Edit 2: Yes, please!  I am very curious of how Eagle mounted the air bags from the factory.  Sorry about the last schematic (fuel line diagram)-- send it however is easiest for you.  Facebook, Google+, email, post office-- you name it.

If you go the jack route mount those in front of the front tire not behind the tire, Big Foot mount theirs behind the front wheel and are not real stable IMO

The nice thing about air bags is, it is much easier to control "bleed down" in an air leveling system.  All that is needed is a control panel with four adjustable pressure regulators, four lowering valves, and four pressure gauges.  I might scrap the jacks idea in favor of air bags, just for the future-proofing and proven working design.

Check the edits on my previous post.

Edit: On second thought... I should wait to see how Eagle plumbed them on the schematic.  The unloading of the suspension on bumps would cause the pressure regulators to continually overfill the air bags.

Question:   Are you going to used oil in the air line tubing??
Bruce

Bruce- That jack uses air pressure to run the hydraulic pump on the jack.  Oil does not get inside the air tubing.

This Youtube video shows the air operated hydraulic pump.  The jack shown is a lot smaller than the long ram I posted earlier.
https://www.youtube.com/watch?v=J44ib1npZdM#t=267 (https://www.youtube.com/watch?v=J44ib1npZdM#t=267)

The problem with this set up is that to let the jack back down you have to turn the threaded valve at the base of the jack.  Not sure how you would do that without squashing yourself.  Also would have to lower one corner at a time.  The air valve only allows you to go up, not down.

Quote from: sparkplug188 on November 14, 2014, 06:57:02 AM
Has anybody thought of using these:

8 Ton Long Ram Air/Hydraulic Jack
http://www.harborfreight.com/8-ton-long-ram-air-hydraulic-jack-94562.html (http://www.harborfreight.com/8-ton-long-ram-air-hydraulic-jack-94562.html)

16,000lbs capacity
air operated, manual backup
17.5" stroke
35.7lbs

It would need a large retracting spring, like this:

National Hardware 7688 Garage Door Extension Spring with Safety Cable
http://www.amazon.com/National-Hardware-Extension-25-Inch-110-Pound/dp/B000B4N0SO/ref=sr_1_1?ie=UTF8&qid=1415974854&sr=8-1&keywords=garage+door+spring (http://www.amazon.com/National-Hardware-Extension-25-Inch-110-Pound/dp/B000B4N0SO/ref=sr_1_1?ie=UTF8&qid=1415974854&sr=8-1&keywords=garage+door+spring)

Both mounting points on the jack are pivots, so they can't be mounted like "normal" RV leveling jacks (straight up and down, without bracing).  They need to mount similar to backhoe outriggers- see the first picture below.  On a bus, I would mount the ram nearly vertical and mount the outrigger pivot near the differential- see second picture below.

(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FQ7U8fZa.jpg&hash=a0d803c8e37dc9ecfb89b19859b27305c4844acf)

(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FqOygbcc.jpg&hash=3b311aea56d3725d4cb23063e4dcfbde5b8dd159)

I do not know how the professional leveling systems deal with hydraulic "bleed down".  There must be some sort of locking system that I am not seeing.  I am not sure how to lock outriggers in place.  There is probably a simple way to do it that I am not thinking of.

It wouldn't be a fully automatic leveling system, but it would be an effortless way to level a bus without spending $4000+ on a leveling system.

Thor- You're right.  That setup is only slightly better than carrying jacks and jack stands for leveling.  The threaded valve at the base of the jack could be reached with a long jack handle.  Also, an air valve would need to be mounted on the skin next to each wheel for lowering each jack.  I am really thinking an air leveling system is the better way to go.  The air bags cost about the same to install (on an Eagle), but can easily be hooked up to an automatic leveling/dump valve. "Bleed down" won't be as much of a problem with automatic valves.   It won't be as rock solid stable as hydraulics, but I can live with it.  For long term parking on air bags, I could just air up the bags and put jack stands under each corner to stop the rocking.

To make sure the coach doesn't rock I just tell my wife to walk more evenly when she gets up in the middle of the night.  Works for me.

Quote from: MightyThor on November 14, 2014, 01:46:02 PMTo make sure the coach doesn't rock I just tell my wife to walk more evenly when she gets up in the middle of the night.  Works for me.   

     Yeah, that works.  I did that once - was out of intensive care in just a few days.  Something about the words "do you have to walk so heavily ..?" seemed to cause a problem!

The valve to hold the cylinder in place is called a lock valve. They are mounted close to the cylinder. It locks both sides of the cylinder. It unlocks when the pressure is greater than the lock pressure. It is a common valve on stabilizers on cranes. I have them on our 05 leveling system and they work well. One problem I have two cylinders mounted in the engine compartment. When they are all the way up and cool and you drive and warm up the cylinder the pressure gets higher than the pump pressure so the lock valve will not unlock. Solution leave the cylinder extended slightly so the pressure will not build.

Wayne

A few 2Xs of lumber to drive on to level the bus works good, low tech, quick and easy...

JC


Sent from my iPhone using Tapatalk

JC- No doubt 2x lumber will get the job done.  However, there is so something to be said about the convenience of pulling into a camping spot and automatically leveling in just a few seconds.  My previous RVs took 30 to 45 minutes to set up camp, with the longest and most physical part being leveling.  It took anywhere from two to five tries of adjusting the thickness of the blocks to get level. It wasn't practical to level the RV with blocks for overnight parking.

I think it is worth $500 and several days of fabrication to have some sort of quick(er) leveling system.

Yep airbags with block off plates. at four corners ;D

I use a 1/2 x 4' piece of pipe to let down my Air overs when I need to let air out of a jack when working on the Bus. I used a dead blow hammer and just gave it a whack to egg shape the end. It fits right over the air release screw.

Very true, with the original 3-pt system the bus is indeed twisted when parked on uneven ground.



Jacks - The problem with jacks is they punch holes in stuff and get stuck! No comparison to an air bag leveling system

I just replaced the two rear leveling valves and planned to replace the front ones when I get new bags and plate the front.  I'm now thinking of adding a leveling system and can't figure out how people have retained the OTR system and integrated the leveling system for the 4 corners.  Everything I can come u with has one defeating the other at some point.

Clifford- Any luck finding the schematic for the Eagle factory installed air bags?  I sent an email to your gmail account, but have not received a reply yet.

If anybody has Eagle manuals on CD that you don't need anymore, please let me know.  I am interested in bartering for or buying manuals for the model 1, 10, and 15 just for reference.

Don- Haldex makes a COLAS hand control valve that automatically overrides the height control valve when the parking brakes are set.
http://www.haldex.com/en/North-America/Applications-Products/Brake--Suspension-Systems/Product-Catalog/Suspension-Controls/Valves/Hand-Control-Valves/Colas-Hand-Valve/90555270 (http://www.haldex.com/en/North-America/Applications-Products/Brake--Suspension-Systems/Product-Catalog/Suspension-Controls/Valves/Hand-Control-Valves/Colas-Hand-Valve/90555270)

HWH makes several air leveling systems that work with the existing height control valves and air bags.  However, I have found it very difficult to find pricing and information on the HWH air leveling retrofit systems.

I won't be back home till the end of the week then I can send those to you

Clifford- No problem, Thanks again  ;D

Quote from: solodon on November 15, 2014, 08:46:49 PM
I just replaced the two rear leveling valves and planned to replace the front ones when I get new bags and plate the front.  I'm now thinking of adding a leveling system and can't figure out how people have retained the OTR system and integrated the leveling system for the 4 corners.  Everything I can come u with has one defeating the other at some point.

Somewhere is a complete description of a manual leveling system, must have been sometime this year, and it was a good one.

I once thought about adding a fourth valve to the front and running rods from each valve up through the floor.

Crude, but I think it would work. A pain to adjust though from 4 points so far apart.

The secret to leveling the bus when parked is to let as much air out as possible from the high end and then adding to the other end as necessary. This helps eliminate the rocking boat effect.

gus- What if you used some light duty linear actuators in place of the factory installed rods connecting the height control valves to the axles?  Use actuators that are the same length as the factory installed rods when fully retracted.  As the actuator extends, it will add more air to the connected air bag.  Wire the actuators to a control panel with up/down switches and bubble levels.  It is probably a good idea to include pressure gauges on the control panel to monitor the pressure inside the bags and pressure switches to prevent over-inflation by opening the "extend actuator" circuit.  It would be fairly easy to add a safety mechanism to automatically retract the actuators when the parking brake is released.  This system will maintain height even if air leaks out of the bags.

I am just thinking out loud-- I have never built or heard of a leveling system like that.  It should work though.  Let me know if you see any flaws in that idea.

- Spark

I think that Electrical Sean had actuators on his height control valves to use for leveling.  We have a simple system inspired by Robert G. that just uses cables to replace the rod to the height control valve.  You simply push or pull the cable to level the bus.  I think my system was less than $100. Works fine, but it is not controlled from the dash. You have to go outside to use it. 

Anyway, as I generally remind guys looking to level with airbags, whichever way you activate it, it has only limited range-- only about a 6-7 inch differential from the front to the back.  This means that you are not 100% free of using blocks.  We have been in many Forest Service campgrounds that have a good 12 inch differential in their most level spots.  Commercial campgrounds though are generally within the range the airbags can give you.

Quote from: sparkplug188 on November 17, 2014, 09:01:15 PM
gus- What if you used some light duty linear actuators in place of the factory installed rods connecting the height control valves to the axles?  Use actuators that are the same length as the factory installed rods when fully retracted.  As the actuator extends, it will add more air to the connected air bag.  Wire the actuators to a control panel with up/down switches and bubble levels.  It is probably a good idea to include pressure gauges on the control panel to monitor the pressure inside the bags and pressure switches to prevent over-inflation by opening the "extend actuator" circuit.  It would be fairly easy to add a safety mechanism to automatically retract the actuators when the parking brake is released.  This system will maintain height even if air leaks out of the bags.

I am just thinking out loud-- I have never built or heard of a leveling system like that.  It should work though.  Let me know if you see any flaws in that idea.

- Spark

I haven't done one so you need to get advice from those who have - there are at least a couple here. I stopped my thinking about it when I got the 4107 already equipped with a leveling system.

One posted full details and a whole bunch of pics, you need to search that one here.

Quote from: luvrbusThe HWH mounted on the Eagle were on a angle like 12 inches over center when extended lol the 4000 bucks is for the Big Foot leveling system, Jesse the HWH 64,000 lbs I had installed cost a little more lol almost double.

Clifford- Why is it that when I come up with a unique design, you tell me about a cool hydraulic leveling system--  Then, a few weeks later this shows up on my doorstep?

Quote from: sparkplug188:o NOPE! 100X nope! I would live life tilted a few degrees sideways and save the $8000 for a rebuilt engine.  My experiment will cost no more than $500 in materials.  That is about as much as I will pay for a level bus.

Yep-- eating my own words now.  Still, I didn't pay full retail and never would. They are Big Foot QEII-24's 17,600 lb lift capacity per cylinder.

Just messing with you Clifford. You probably saved me the expense of multiple redesigns and failed tests that would eventually lead to me buying a prebuilt system, but not before my design got stuck up, then stuck down, then bent and broke off LOL!