Have you added an air dryer?

[Larry Fritz]

I plan to add an air dryer to our coach. No air brakes.

If you have added one I would appreciate hearing from you and what brand and model and the results so far.

[Keith Oliver]

In theory, you already have dry air, by opening the spigots in the service bay and allowing the air pressure to blow all of the collected water out.  The lines to the spigots come from the low points on the air tank, so all the accumulated water is forced out first.

In coaches with air brakes, getting rid of the air is much more critical to the proper operation of the brakes, so a dryer is important. In our air over hydraulic systems, whether the air is wet or dry is not so important, as all the air driven systems on our coaches are less prone to failure with wet air than are air brakes.  It is good practice to blow the water out after any long run, so as to not allow a buildup of water.  

[Larry Fritz]

Keith, thanks for your insights. I  try hard to drain the water frequently.  Last winter (in November) we had a awful experience. We had camped overnight and the outside air temp was 10 degrees. I started both the gen and the CAT twice during the night to hopefully ward off problems. After over two hours of driving, we suddenly lost air on the driver rear. Eventually, that air level valve was replaced. That solved the ride problem but now my dash green (wet) gauge permanently reads 30 psi higher than it should. Meanwhile, we did not use the air dump a single time over winter trying to ward off any more problems. (We were in generally 15 to 40 degree weather most of the winter).

When we arrived home in Nebraska about April 1 this year, the driver side started leaking down overnight. I could not locate a leak with soap and water so I changed the air level valve again for a test. (blew out the lines when they were disconnected) That was not the problem. The problem positively turned out to be a leaking seat on the 12V solenoid air dump valve. I ordered a new identical valve, blew out the lines, and it worked fine for 3 complete air dumps and re-air of the coach. I then took it on the highway for a two mile drive and returned home. Guess what? It was leaking again (the new one).

I have been running many tests. Some repeat and some don't!  Have been flushing the air dump valve with air (both directions) and WD40  with mixed results.

Several people have suggested that I add a air dryer to help keep "crap" out of the tank and system as well as water and that is the path that I am pursuing at this time. Not sure if I will do it or not.

Meanwhile, if I want to give up "air dumping" entirely, I just crawl under the coach and turn those mechanical brass valves at the air dump valve output ninety degrees and NO LEAKS OF ANY KIND FOR DAYS!

BUT, I really want to use my system and am not sure what to do or try next.

Keep the suggestions coming. Any  ideas on how to clean the seats on those cyclone valves?

Larry Fritz
Adams, Nebraska

[Edward Buker]

Larry,

If I had that kind of trouble i would consider moving the solenoid valve to a side compartment with a set of manual valves to bypass it. Might even put a water filter seperator inline before it to keep the seat clean and reduce the water that gets into it. Water may be the root cause but from that I would suspect some corrosion debris from metal surfaces within the tanks etc as a likely cause of seat failure. At least having the dump solenoid where it was servicable with a manual back up valve in parallel would make life on the road easier.

Later Ed

[JimDyer]

In theory, you already have dry air, by opening the spigots in the service bay and allowing the air pressure to blow all of the collected water out.  The lines to the spigots come from the low points on the air tank, so all the accumulated water is forced out first.

In coaches with air brakes, getting rid of the air is much more critical to the proper operation of the brakes, so a dryer is important. In our air over hydraulic systems, whether the air is wet or dry is not so important, as all the air driven systems on our coaches are less prone to failure with wet air than are air brakes.  It is good practice to blow the water out after any long run, so as to not allow a buildup of water.  

Keith, it isn't true that the water is all forced out first. Air can push its' way to the front and leave water sitting while air blows out first. That is why it is important to completely drain the compressed air out of the air system to get all the water out.

[JimDyer]

Keith, thanks for your insights. I  try hard to drain the water frequently.  Last winter (in November) we had a awful experience. We had camped overnight and the outside air temp was 10 degrees. I started both the gen and the CAT twice during the night to hopefully ward off problems. After over two hours of driving, we suddenly lost air on the driver rear. Eventually, that air level valve was replaced. That solved the ride problem but now my dash green (wet) gauge permanently reads 30 psi higher than it should. Meanwhile, we did not use the air dump a single time over winter trying to ward off any more problems. (We were in generally 15 to 40 degree weather most of the winter).

Larry Fritz
Adams, Nebraska

Larry, are you sure that the green gauge is a wet air receiver? On my 98 Marquis the two colors refer to front brake tank and rear brake tank.....