I’m not familiar with your particular coach, but Haldex and Neway are common valves for height control.
http://www.heightcontrolvalve.com/haldex-19.htm Search online and you’ll see a number of sources, and I’d expect them to be available locally at truck and/or auto parts suppliers. But there are different types I think depending on application, such as trailer, semi-truck, motorcoach, and other uses. You’ll need to determine the correct one, hopefully from markings on the ones on your coach, or perhaps it’s noted in the document you found.
If the coach is like many, there is one valve for the front of the coach and two for the rear axle. Any or all could be faulty, and working with the air system is best done by experienced techs, Rick, most of whom would have either a lift or a pit. They can dump all the air and still easily work safely standing up. An ideal situation would be letting a coach or truck repair facility handle the task; Henderson’s Lineup would be my preferred venue, or BCS, but may not be geographically plausible for you. If you have some experience and feel comfortable working on it yourself, of course that’s up to you and can save labor costs. But I wouldn’t expect a good tech to take particularly long changing out these valves.
At this point I take it you don’t know for sure if the leak mentioned in the document refers to the actual valve (internally) or perhaps just a fitting, if it’s not the more common linkage rubber boot failure, and it doesn’t specify which valve is involved.
Some coach manuals diagram the air system as a generalization. If you don’t have at least that, you may find one in one of the newer manuals here in the Coach Assist section, but I can’t say how much your year coach may vary from them. If needed one of us could probably post for you here a photo or scan of ours if it would be helpful.
Joel
