Quote Originally Posted by Jon Wehrenberg View Post

Any coach as it ages develops "ghosts". A little used coach may have more issues than a coach that is used often, but the bottom line is if it is made of rubber there will come a time when it needs to be replaced, not because of wear or use, but because it has aged out. A perfect example is tires. The major tire manufacturers agree that when a tire has been in service for 6 years its life is just about over, and at 10 years from the date of manufacture they wash their hands of any warranty support on a tire.

From my experience air bags start to get checking and cracking at the point where they roll over the "piston". The suspension Norgren valves are likely to start leaking if they haven't already, brake chamber diaphragms may be getting prone to cracking or leaking, etc. If the coach has slides the seals may be getting brittle and likely to start leaking. But this has nothing to do with whether the coach was sitting or being used. This is what happens. Maintenance is an ongoing process and regular use somehow tends to prolong the life of some components, but it doesn't prevent the ravages of age. I think people that buy coaches with low mileage and the expectation that those low miles translate into a trouble free product get disappointed when they realize those low mileage coaches still require maintenance.

That coach may have issues with the bushings in the front suspension A frames or sway bars or shock absorbers. All of this is normal and if you budget to deal with these issues you could end up with a very good coach in new condition (mechanically).

If you are a do-it yourselfer, relatively speaking the cost to bring these above items up to date will take a week or so of your time and a few dollars relative to the cost of the coach. The thing to remember is a coach that was frequently used compared to one that has not been used much may still need to have every item listed above replaced. That is not to say the rarely used coach is not going to have some issues as a result of non use. Depending on where and how it was stored there could be corrosion inside the engine. The roof could be suffering from leaks due to aging of the seals around all openings, something that would have been maintained on a coach that was used often.
The above was posted today on a thread titled "What do you guys think". It seemed like a tailor made way to blame my current project on Jon "da man". Our '99 Royale is now 13 years old and we had no maintenance records that could confirm if any of the aging rubber components had been changed and I subsequently found they hadn't. So, since I had nothing better to do it seemed a good time to do a little updating. The first pic below is a pile of most of the rear end rubber components. Add to these the radius rod bushings (12), Norgren valves (8 in our bus), and shocks (8) and you'll get an idea of how much "stuff" gets old, brittle and cracked. A couple of additional pics show airbag checking, a stretched shock bushing, and a badly corroded Norgren valve. Incidentally, except for a year on Liberty's sales lot, this bus had always been garaged.

Last year I started the project with the replacement of the front end components. These included all of the front suspension bushings and the steering rod ends. We should all be aware that the steering rod grease boots can easily be ruined by an over zealous lube technician. Too much grease in any of the rod end zerk fittings will split these boots causing a colossal mess and exposing the steering rod ends to the weather. In our bus every one of them had been exploded from too much grease. The fix is to replace the entire rod end since the boot is integral to the part. Incidentally, according to the previous and only other owner of the bus, ALL of it's regular service had been accomplished at Prevost Service Centers.

Commercial truck parts suppliers can duplicate some Prevost parts. Brake Chambers and brake hoses, are examples. Air bags and Norgren valves might be available from other sources but they probably won't beat Prevost prices. Cross referencing part numbers can be confusing at best.

Had it not been for the encouragement of Jon and Kevin Erion along with Jon's terrific "information Sharing" articles, I would never have attempted this project. Jon's Prevost Maintenance Schedule and Replacement Parts were especially helpful. The appropriate Prevost Maintenance Manual should always be the major source for any maintenance operation. A review of proper jacking procedures in the Owner/Operators manual should be reviewed every time you need to crawl under the bus.



IMG_0295.JPGShock Bushing.JPGAirbag Checking.JPG3 Port Norgren.JPG