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Jerry Winchester
03-08-2011, 10:01 PM
Since poor folks have poor ways and I can't afford a pit nor do I have a friend with a pit or a bus lift, I decided to make a set of ramps to lift the back of my bus so I can install the toad brake system.

A quick trip to Home Depot netted some plywood that just fit the bill. So now I can slide under the back and get the requisite valve & tank installed. For those who saw the first installation (POG 4 @ Sevierville), we leaned the bus over to one side and a skinny kid slipped between the duals and the tag where he proceeded to sit upright under the bus and install the gear.

I don't think my shadow would fit between those tires.

http://3.bp.blogspot.com/-HUo3dAJXaiU/TXbpmACGUkI/AAAAAAAABHI/YVnF9gF6N-Q/s1600/photo-779248.JPG

http://2.bp.blogspot.com/-TwAKteSW4sY/TXbpqCYVRPI/AAAAAAAABHQ/rEnrBVZ4L6M/s1600/photo-796570.JPG

JIM KELLER
03-09-2011, 07:20 AM
Great idea. I never thought of building ramps to raise only the drive axel. Does the tag just hang in the air ? Do you loose much height when the bus sags w/o the tag supporting some of the weight ?

Jon Wehrenberg
03-09-2011, 08:06 AM
For 10 years I layed on a barn floor working on my coach. I raised the coach to its full height on the suspension and then supported it under the support points with hardwood blocks.

I could do anything I needed to do on the coach primarily because once you get into the area by the axles you can sit up or work on your knees. If you use ramps to raise the coach you are not safe if you go under the coach unless you support the chassis or the coach is all the way down on the air bags. Ramps are a big help but have to be used safely. Where ramps are a big advantage is if you can raise the bus to the full height on its air bags while the coach is on ramps and then support the chassis before going under the coach. The extra few inches when working under a coach is valuable in the context of giving more room to slide under on a creeper or to be able to maneuver when beneath the coach.

But remember, never ever get under a coach unless it is supported at the body support points or it is all the way down on the suspension.

Loc
03-09-2011, 08:13 AM
Jethro Bodine would be proud.

Jerry Winchester
03-09-2011, 08:58 AM
Jim,

I raised the tag before I put it on the ramps and I have a set of the POG special -Jon engineered stands to keep from having a Loc moment.

merle&louise
03-09-2011, 09:10 AM
When I was at CoachWorx last month I noticed that they use wooden ramps to gain access the underside of the coach. They had 2X8 boards nailed & glued together on the vertical edge. The boards were cut on an angle and had plywood nailed to the top. Birdland Coach Services in Houston uses the same set up.

Good idea!

Jon Wehrenberg
03-09-2011, 11:30 AM
Just as a comment to those who bring their bus to someone for service........

I have never seen a tech support the coach under the support points before getting beneath the coach, or lower the coach all the way down on the suspension. I'm pretty sure they get complacent and never think about the coach settling, or an air bag bursting. But it happens and the danger cannot be overstated.

I have seen Prevost lift a coach using their jacks under the steer and drive wheels. I am not aware of anyone including Prevost asking the owner to lower the coach all the way down before they lift it. I don't know how stable those jacks are, but if an air bag bursts, the coach is going to drop very fast until it sits all the way down on the suspension so it likely will not go more than 4" or so, but what happens if the tech has his arm or head in a pinch point when that happens. The resultant quick lean (not all air bags will lose air if one bursts, just those that are in a specific area like front or left rear) may compromise the stability of the jacks. I'm guessing, and never really want to find out if I am right.

Nobody will like you telling them how to do their work, especially the techs, and especially when the advice comes from the owner of a Prevost, but it might not be a bad idea to tell them anyway. If might save someone's life.

phorner
03-09-2011, 11:33 AM
Jethro Bodine would be proud.

Now that was way harsh.....

Jerry Winchester
03-09-2011, 02:02 PM
And Paul that was from a guy who has a Beagle on airbags. Geeze.

Oh wait, that was a Beagle who swollowed an airbag. My bad.

GDeen
03-09-2011, 06:47 PM
Interesting point Jon,

Shortly after buying my coach, I had an Air Force One braking system installed. The tech (not Prevost) had me raise the bus all the way up and jumped under it. As he started fooling with air lines looking for a satisfactory splice point, I got nervous. I suggested he support the chassis which he ignored. I then went and told the service manager I wasn't interested in watching his hand get crushed should he somehow bleed a bag. The SM didn't seem too concerned, but made him do it just so I would shut up. I was very surprised at the lack of concern, particularly since he was working with the air system.

Jon Wehrenberg
03-09-2011, 07:28 PM
In theory nothing should happen. If the key is off the 5 port Norgrens go to their normal position and "lock" air in the air bags.

At least that's the theory. That guy under your coach probably didn't even ask you if your bus had the leans. So your coach could have lost air slowly and lowered the bus on him. Or since raising the bus up in the air puts full system pressure into the air bags, or about 125 PSI, the air bag pressure limit of 100 PSI was exceeded and the air bags could have burst. Was the risk great? No. But what if only one in 1000 buses ever drops? What if the odds are 1 in 10,000 buses? At what point do the odds get so good the risk is so slight as to not make it worth while to support the chassis?

My bus is over the pit and right now it is also sitting on the stands. The few minutes it takes to raise the bus and slip the stands in place makes the odds I will go in the pit to look at something and have the bus drop on me are pretty close to zero. Why guys that work on buses for a living aren't afraid of them (or respect what can happen) escapes me.

garyde
03-09-2011, 10:34 PM
Safety, Safety, Safety. This should be the primary focus every day in any work environment. Unfortunately, many workers get complacent and it is entirely up to mangement to keep their emplyees safe. Managers, supervisors and lead Mechanics should all know what is safe and what is not.
I can't believe how many times I have seen workers go under coaches without support. Its the norm not the exception.
At the Indio MCC Mini rally several weeks ago, two Prevost mechanic went scrambling under Ray's coach to remove the transmission sensor before we could get the supports out and placed under the coach. They did'nt even ask, we insisted.

phorner
03-10-2011, 08:29 AM
Safety while under the bus can't be over emphasized.

Not long after we had our Air Force One installed, it came apart creating a sizable air leak. Luckily, we were in a fuel stop and, before the emergency brake actuated, I was able to get the bus into an open area for inspection and repair.

SMI sent a repairman to our location from a local RV dealer and he was prepared to simply dive under the bus.

I finally convinced him that although the bus looked good, it was imperative to provide suitable support. We spent 30 minutes or so gathering up enough support equipment between the two of us (I didn't have Jon's bus stands at that time.....) and securing the bus for what ended up being a 1 minute repair.

Then of course, we had to spend considerable time removing the jacks and blocking.

But it was well worth the investment of time. It is simply not worth the risk to be under a bus without proper support.

Toy Box
03-10-2011, 10:47 AM
Jon, could you again post the pictures of the four points to use to properly block the bus in the raised position? I can't seem to find them. Thanks.

JIM CHALOUPKA
03-10-2011, 12:21 PM
Go to the POG home page and in the menu select information sharing, under that heading scroll down until you find the support point information.

JIM :)

michaeldterry
03-10-2011, 12:39 PM
Go to the POG home page and in the menu select information sharing, under that heading scroll down until you find the support point information.

JIM :)

Thanks for the guidepost, Jim! Jon's article on support points has been saved to my computer as an MS Word documemt and now resides in my important bus documents file for easy retrieval as needed.

Jon Wehrenberg
03-10-2011, 01:22 PM
George,

A picture is worth a thousand words. The photo below is at the rear, and you are looking at the square cross member behind the tag axle. As you can see the stands are directly beneath the vertical structural component to which the square cross member attaches. As an alternative (which I have done also) you can place the stands directly under the vertical "post" but the surface is minimal which is why I prefer to use the corss member as the contact point.

7924

IN the photo below it is taken from in front of the steer tire looking towards the rear. There is a structural member going cross wise ahead of the axle, and from that cross member two structural members extend forward. I place the stands under the cross member where the two forward pointing members are attached.

There is also a front support point behind the axle, and you can identify it as being directly beneath a structural component of the steer axle structure that goes vertical. I prefer to use the front support points.

Just a note that all should be aware of. In the not too distant past Prevost was supplying the wrong air bags and some coaches do not have the correct air bags. As a result the fully raised height may make it difficult to get stands under some buses. Another factor may be the choice of shock absorbers which in the steer axle are the limiting factor in raising the coach. On my coach the rear supports go under the frame easily as long as I leave the front down and only raise the rear to its maximum height.

When the rear stands are in place I then raise the front as high as it will go and the front stands will go in place. Using this method I have 1/4 to 1/2" clearance between the stands and the support points. Some coaches will not go as high as necessary and because of all the factors that influence the raised height it is only a guess as to why. For those coaches I suggest you consider placing a piece of plywood or a 2 X 10 under the wheels to provide the clearance above the stands if needed.

I hope this helps.

This does not apply to an H3, however the principle is the same. Look for a vertical structural member and it is likely that is the chassis support point. Never ever place stands under the axles or axle components including any of the pivot arms.







7925

Toy Box
03-10-2011, 01:50 PM
Thanks, Jon, you are the best. Hope to see you and that car salesman buddy somewhere on the road.!!! thanks again. The stands afford so much safety for so little effort.

gmcbuffalo
03-10-2011, 03:33 PM
I was thinking that it would be a good idea after identifying the support points to take some spray paint and mark these points. Just a spot of paint to easily identify the point. One color for chassis support ports points and another color for the jack point for lifting the axles for a tire chain. Not just for yourself but to help anyone the is going to work on your coach. I remember on my first coach I blow a outer dual tire, I limp in to a truck stop, the guy told me he knew the where to put the jacks. The bus was new to me and I really didn't know the correct point. So I watched the guy run the jacks under the coach and bend some metal under the coach. I believe it would be easier to tell someone where to put their jack if you just tell them to look for the Orange spots chassis supports or Green for axles points. These points are confusing for us let alone some mechanic on the road who doesn't know squat about our busses.

truk4u
03-10-2011, 07:59 PM
Whats the green hose for? Oops, I forgot, it's the rope light that go to the dinga balls that hang from your awning! Or did you change out the dinga balls for the chili pepper lights?

7930

Jon Wehrenberg
03-10-2011, 08:09 PM
Those are poor man's neon underbody lights. Only they are not neon.

Bite me.

Reagan Sirmons
03-12-2011, 12:30 AM
Jdub,
Are those fenders burnt orange?
Pres