I was talking with James Stallings who told me that his book from CC said to dump the tag when you level. The reason is that there is no leveling on the tag and it fights the air bag for the tag if it is higher than the front. I never thought of this but will try it next time and on slopes it seems to make sense.
HWH systems are not all the same. What applies to a CC may not apply to a Foretravel.
From studying the Foretravel HWH manuals, the tag axle air bags are part of the leveling system.
I do not have a lifting tag and will have to look next time I level. I will look at the manual when I can get in the coach too.
I don't know everything about every CC but I do know about mine. I have a 2003 42 CC Magna with liftable tag and HWH air leveling. If I try to level with the tag lifted I will get to level but will need frequent auto adjustment. If the tag is not lifted the leveling will occur more quickly and be more stable. I believe that the tag is performing some leveling function.
In addition, the CC documentation for my Magna does not require dropping air before leveling. I rarely do that.
Interesting. The documentation that james has says to lift the tag on his coach. Maybe provost level differently but I would think that if you wanted to keep the front as low as possible or to be able to level on a steeper hill, lifting the tag would help that.
I don't believe that Prevost uses HWH leveling. Rather they use a proprietary system I think. At least the newer ones do and I don't know what James has.
If you want to level with the front as low as possible you would simply drop air down to the bump stops before leveling.
Yes, Prevost do use HWH; however, it is a different system than used on Foretravel and most other coaches. You can read about the Prevost HWH system in the HWH Air System Textbook. Here is a quote:
"Prevost automatic air leveling systems are not like other HWH
air leveling systems. Prevost air leveling systems are always
3-point leveling systems. At this time, they cannot be done as
a 4-point leveling system. Prevost air leveling systems do not
use air solenoid manifolds. The Prevost air valves are used for
leveling functions."
we looked at mine and yes the tag does work in the leveling system. Dumping the tag had no effect on the leveling.