Quote Originally Posted by Jon Wehrenberg View Post
Several years ago the King and I decided to change all the air bags on our coaches. The incentive was that Roger wanted to change them, but Prevost had shipped the wrong front air bags.


Our motorhome shells are designed to have about 4" of both up and down travel from ride height. The purpose is to allow leveling on uneven campsites. A seated coach is designed to go down (kneel), but not be raised above normal ride height. It is likely that anyone that orders air bags for their coach or has them replaced by Prevost is not going to get airbags the equivalent of what was on the coach when it was built. Prevost continues to ship and install the wrong airbags on motorhome coaches.

This is a critical piece of information that everyone should know and understand. If you are going to have air bags for your coach replaced there are some things you should do. First, measure the ride height, the lowered height and the maximum raised height of your coach. The proper way is to measure the distance between the upper and lower air bag mounting plates, but it is just as easy and understandable to measure from the bottom of the bay door just behind the front wheel to the floor surface. When having the air bags replaced be certain that the installer understands you need to retain the amount of travel you have, and that if you do not get that travel with new air bags they need to be replaced with those that will provide the travel.

There are other issues related to this that all of you should know. First, the current air bags being supplied have larger fittings for the air supply, and the top mounting plates on some coaches do not have a hole large enough to accomodate the fitting. The hole in the top mounting plate in that case may need to be bored or torched out to a larger diameter to accomodate the fitting in the top of the air bag. Another issue is travel. While it is important to retain the amount of vertical rise above ride height, it is equally important to not have an air bag that will provide more travel. It is possible to break the top mounting ring from a shock absorber if there is too much air bag travel. A broken shock absorber can do some damage so it is important to not install airbags that can break the shocks.


If you allow yourselves to become a victim of reduced height due to the wrong airbags remember Prevost will not correct the problem. To their way of thinking the air bags they list and install are what is called for in their parts lists and they will not do anything to correct this so it is up to you to get an understanding from Prevost up front as to what you expect after air bags are replaced. It may not seem like a big deal now, but if you damage the lower front of your coach or wipe out a generator baffle because you cannot raise your coach up this issue will take on a greater significance.
OK, so if I have this right, (I fall into the late 80's early 90's category) If I go to Prevost they will put in 2 new airbags (after enlarging the mentioned access hole) that will not raise my bus over its required ride height. I will be in a pickle for some manuvering which could cause damage. If I put the other air bags in that could possibly raise my coach beyond the 4" excess height, I could pull apart a shock and also cause damage. SO if I then decide I should change my shocks to prevent an overheight inflation situation, can I find shocks that will be long enough when extended to avoid this? Conversely as mentioned by others, maybe a different airbag other than Goodyear 259 or 260 can be found? I must say this is a stimulating subject and I thank the MPD Gods for guiding me to POG to provide this assistance.
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