Air Bag Ride Height Dimension - 259 Bag

[Jon Wehrenberg]

Paul, The advice so far has been good. Here are some ideas that might be part or all of your problem.

First, if the five port norgren is not shifting it will have that problem. I have ruled out the solenoid valve because the front and other side are working so corrosion or a lazy 5 port norgren can be the issue. Try exercising it by seeing if you can raise or lower the side in question using the manual position and then go back to the road position.

One cause for what you describe that a lot of folks overlook is related to the road height valves. The arm position controls the operation of the valve, but it the arm passes its extreme limits no air will flow through the valve in either direction. I am not familiar with the instant response valves you have, but on the delayed respnse valves if the postion of the bus has passed its normal operating range, the only way to restore the valves to functioning is to manually adjust the coach height to get it within the valve operating range.

So you may wish to manually raise the coach a few inches and then see if it will automatially go to road height. The answer is only within the five port norgren and the ride height valve on that side.

[phorner]

I decided to try to "exercise" the system to (A) better document the problem and (B) see if the symptom improves.

It appears that the problem has "self-resolved" which is both good and bad news. Glad everything's working OK but sure wish I knew for sure what the problem was.

I manually raised and lowered the bus to the high and low limits, and then went to ride height from both extremes. Then resumed to ride height after just a little bit too high and a little bit too low. Then back to full travel at both extremes. Then the whole pattern all over again.

One interesting side note: I decided to take measurements as the bus was moving up and down. The front ride height returned to the same constant whether achieving ride height from either full up or full down position.

However, if I dropped down to road ride height after the bus was at the upper height limit, the rear returned to an elevation 1/2" higher than achieving road height by raising from the lowest position.

Of course, this was strictly a static test. I'm guessing that if I drove the bus any distance, the rear ride height would settle out to be the same either way as the ride height valves adjust up and down during travel.

[Jon Wehrenberg]

Paul it was either a lazy 5 port norgren or you were beyond the limit for the ride height valve.

Whatever it was ignore it because whatever it was is gone and exercising the coach will do nothing but good for it.

Some things are not worth worrying about. That's one of them.

[charlesebrownjr]

I need to know if any of you have the correct part # for air bags for a 40' XL CC. My bags are now 10 yrs. old and I will most likely replace them this summer or next fall but I have seen post where everyone says that the bags Prevost wants to use are not the correct ones. Help

[Steve Bennett]

Paul, you may still want to take a look at the leveling valves. We have seen them get contaminated from oil coming from the compressor. If you look at the port on the bottom of your air dryer, and see a fair amount of oil, or can see any oil on the bottom of the leveling valve ports, that is your likely problem. If the valves get contaminated with oil, they will stick and be slow to respond. Generally replacing the leveling valves, and servicing the dryer will eliminate any future problems. Charles, Prevost has updated their information on the proper air bags. Make sure you provide them with your vin#, and make sure they know it is a motorhome.