Leveling jacks

[Jim Blackwood]

Let's talk hydraulics.

When I had my 32' Coachman S&S I rolled my own home brew hydraulic leveling jack system using components I bought off ebay. Didn't look quite as tidy as HWI but did the job and did it well. I'm just sort of wondering about the same sort of thing for the DL3.

The weight is about double, that's the first consideration. I won't be able to use the short cylinders off a car carrier here and might need about a 3" bore. I can run the numbers but somewhere in the 2-1/2 to 3" range should get the job done. I had much more travel than is usual or common, which was a great boon when I needed to get to stuff down below. I also much preferred the double action cylinders. Used 3/8" brake line and a tripod layout.

Now on the D the first big question would be: Where do you mount them? Adjacent to the suspensions I would think but where would be the best spots? Obviously a longer travel distance means a longer vertical distance at the install point. I'd like to see two to 2-1/2 ft of vertical space for the cylinders. The tripod system worked fine but would require a center mount for the front. That might work if there is room and the suspension crossmember is suitable. It would require a rather larger foot. I used automotive flywheels successfully but don't think iron is advisable for this much weight. 3/8 or 1/2" steel plate should be fine though. I did use a spring return on the front which meant a single line. For double acting it might be better to use two hydropacks, one at each end. They can probably still be picked up used for under $200 each. Farm supply stores are good sources for cylinders. Solenoid valves can be had reasonable. Simple toggle switches are all that's needed for the controls, though a auto leveler would be nice. That leaves side loading. The cylinder shaft should be as large of a diameter as possible which could rule out the ag units. What do you guys think?

Jim

[akroyaleagle]

You might want to contact ronthebusnut. Last time I was there he still had a good bit of hydraulic systems that would probably work for you.

[chessie4905]

Why not use the existing air chambers to make your leveling system?

[Jim Blackwood]

Why not use the existing air chambers to make your leveling system?

OK, I'll bite. Tell me why this would be better.

Jim

[buswarrior]

Parts are already present and paid for.

A number of ways to game the levelling valves to inflate or deflate the bags at each corner.

Weight of coach is staying where God and MCI meant for it to be?

A coach can't go mountain goating, so just how uneven are you expecting your camping spot to be?

Adding the structure to withstand forces involved and the hydraulics is going to add some weight?

Lots of busnuts manipulate the air suspension for campsite levelling purposes, you'll be in good company.

Happy coaching!
Buswarrior

[luvrbus]

Not a good idea jacks on the DL 3 they are very flexible if you look at the front of the drive axle you will see a very large S/S bar that runs the full length under the baggage bays to stiffen it up. The early models did not have that bar and MCI sold it as a upgrade because they pop the windshields and windows out because of flexing   

[thomasinnv]

I installed a Valid levelling system in my DL3 and I love it. Uses the existing airbags. I have only had to run up on blocks one time in the 3 years since I put the system in. Pull the park brake, hit the auto level button, and forget about it.

[Jim Blackwood]

How much did it cost?

Jim

[thomasinnv]

How much did it cost?

Jim

Gosh I've slept since then, but I believe it was somewhere just a little over 3K canadian. (Valid manufacturing is a Canadian company. They used to make a lot of air and air/hyd system components for HWH levelling)

[sledhead]

or you could make your own
1 line in ( feed ) and 4 lines out to each corner with no splices
simple push to add air and pull to remove air valves

[goutoe]

I have a hydraulic leveling system on my coach, each cylinder has a pump with internal reservoir  it works very nice it is power up and down I can operate one at a time or all at once the cylinders are approx. 20" retracted, and rod size is 2",  it is especially nice when storing the bus long term it helps keep the weight off of the suspension. I use it mainly to stabilize the bus and make sure I am not twisting or binding it. the hydraulic pumps are the same kind used on outboard boat engine lifts small but powerful.>>>> John.

[Jim Blackwood]

Worth some thought, I'm what I call an "economically challenged" busnut so that looks enticing. So I'm just guessing that when you switch on the engine it settles back to standard ride height but stays leveled until the main switch is flipped? (My power management needs work anyway, heater fans only work when switched power is on.) How far can you lift the bus if you need to get to the undercarriage?

As to cost of the hydraulics, provided that mounts and such can be fabbed from existing materials and accepting that a 2-1/2" cylinder is adequate (= 19635 lb load@1000psi x 3 or 4) figure a couple hundred apeace for new cylinders and about $500 each for hydropacks, you could use one hydropack at each cylinder, minimize the plumbing, possibly even avoid the solenoid valves, about $2200 to $2500 in parts. Used it could be done for half or less but could leak down which is a pain. Or you could use one hydropack and more lines for about $1500 with new parts, solenoid valves and longer lines. Used, about half that. Significant skilled labor.

I'm guessing the costs on the pneumatic solution is under $500 DIY. That certainly makes it attractive, and the ahydraulic jacks can always be added later if desired.

Jim

[richard5933]

...How far can you lift the bus if you need to get to the undercarriage?...
Jim

Not sure exactly where you're going with this part of the question, but in general terms no leveling system should be trusted for working under the bus. For any reason.

I assume you're talking about using the leveling system to get the bus up, after which you would make use of jack stands and/or blocking. But, I wanted to get this out there for those that may not know. I've seen/read lots of posts on other motor home forums with people working under their coaches while only the leveling system was holding things up. Never a good idea.

[goutoe]

Yes when I start the engine the bags air up then I retract the system and the level valves take over, It has a keyed switch to shut off the system so it cant be activated without the key, each switch has a light indicating when the cylinder is retracted. I do use the hydraulics to lift the frame for blocking for repairs, very handy! each cylinder has a base plate on it and I do use wood under them so I don't leave a big footprint! >>>> John.

[Jim Blackwood]

Yes, absolutely never work under anything heavier than you are without something to hold 'er up. 

Seriously though, these things weigh about 45,000 lbs gross. Don't know about you but that's about 188 times what I weigh. It requires serious cribbing. Jack stands should never be rated at anything less than 12 tons at the very minimum and even that might not be safe. On anything but thick concrete they should have solid metal plates under them to spread the load. I've seen the landing gear on a semi trailer poke holes right through blacktop and sink a couple feet into the ground, you don't forget something like that. In addition to which, with that much weight it only takes a very slight misalignment to generate extremely high side forces, enough to bend stuff and jump off stands and cribbing. Be careful, overdo your safety devices.

Now with that out of the way, yes I am very much interested in knowing how much clearance there is under the bus with the air bags fully extended. Provided your safeties are in place, how accessible does it make the underside? (and I presume after extending and blocking you could deflate to service tires and brakes but might need a smaller jack to raise the axle)

This pneumatic leveling system is independent from the suspension system aside from being plumbed into the airbags, yes?

Jim