[Jeffrey & Linda]

Lacking a 24 volt coil for the center solenoid valve you have two choices. Wait for one to replace the existing one, or disconnect the air line feeding the manifold the solenoid valves are on, and connect it to the air line coming from the third solenoid valve down. What that will do is activate the Norgren valves that will let the ride height valves function. You will not have any leveling functions but you will be at the drive height.

The other issues can then be addressed when you get to ETLC.

As far as the water trap and spitter, I don’t know your air system history, but the spitter and the Norgren trap(s) with the valve on the bottom are going to trap moisture from the aux compressor line mostly, but if they have been drained and you still get moisture I would take a hard look at the chassis accessory aiur tank, and if you find moisture there you may have water everywhere.

[Corey]

Jon, thanks for the potential work around for the level low valves. I will hold off on that till I can see if I can get the parts on Monday and see if those fix the issue. Plan is to get all five solenoids (plus some spares) as well as the five level low valves (plus some spares). Replace everything on the level low valve rail and hope that “fixes” the problem. Then I will have Jeff replace the Norgren five port valves for the front/rear/tag when I see him in December.

Earlier this year (june or maybe july) I had jeff check the air system (both chassis and converter sides) for contaminiation. He didnt see any abnormal signs. He repalced the air dryer and put the auto dryer setup on at that time. It’s “spitting” water, so I am assuming it’s working. As I mentioned, when I open the valve on the bottom of the Norgren trap, no water comes out on that. When I am up at jeffs, I will have him purge the overall system again and make sure there isn’t any contimination showing now.

[Corey]

One other issue I noticed is the auto dryer seems to spit all the time when the aux compressor is running, which in turns means the compressor never really fills the system and runs for extended periods of time. Could this be because the coil/valve issue on the level low system? or could the auto dryer have an issue (and it does this when trying to air up the coach while running as well).

Oh and Jon, just to mention, I have been reading through your Prevost Air System document in the articles, as well as a couple pages of Prevostman.com and hectors PDF that he sent me last year that was used in his video webinar. All very helpful resources while trouble shooting this stuff.

[Archived]

Charles,

The good thing about our coaches and their systems is we can work around some issues, so if you do have to take the ride height solenoid out of service by by-passing it you have the equivalent of a suspension without leveling capability. You actually can use the rest of the level low system, but as soon as you take your fingers off the buttons the ride height valves will take over control so don’t attempt to level it until the system is again functional. But at least you can go down the road.

I think the 12 volt coils are exclusive to Liberty but the 24 volt is Prevost and you will have no issues getting that coil. I would not worry about more than one or two spares of the valves themselves, but coils are good spares.

One thing probably not mentioned enough is any articles, including the Prevost Webinar for the suspensions should be considered generic. They are very helpful with providing an overview of a Prevost system, but over the years the suspensions have evolved. Early models with level low up until around 1995 had what we have called the reverse logic (or is it the other way around) in which aux system pressure had to be maintained otherwise the valves that control the path between the drive axle air bags and the tag axle air bags close that open path and exhaust tag axle air bag air. Later models were unaffected by the loss of aux system air pressure.

Later models added “ping” tanks and the front suspension was changed slightly.

Then if you are not yet confused, the converters over the years modified the Prevost system. Not all and not always, but an owner of coaches like Liberty had to be aware the Prevost system was modified to allow for the Liberty auto-level feature. Other coaches used an HWH system to over ride or supplement the Prevoswt system.

So bottom line is when referring to Hector’s great tutorials, or any articles, or the Prevost Webinar, just use the information as an over view and be aware your coach may not be exactly line the ones described.

As to the spitter, I think Jeff can tell you if it is working as intended or if it is excessively discharging air and water. If you think it is creating an issue you can by-pass it with some tubing and a fitting or two. It is unimportant if your air pressure is not coming from the aux compressor. It is unrelated to the solenoid stack which is on the Prevost side of the aux system, well upstream from the spitter.

[AL]

Good info on the 24v VS 12v coil being a Liberty thing. Maybe I’ll call Parliament on Monday rather then Prevost. Think it’a about the same from Silver Springs to either one. I am guessing they will carry some of them in stock as well as the level low valve. If not, then I’ll do the longer drive down to Liberty and get the parts there.

Will also call Jeff on Monday and ask him about the auto dryer and what I should be expecting from that deal and if there is any additional “maintenance” on them rather then what I expected of it just does it’s thing.

Thanks, this forum is a blessing to have such knowledagle people willing to help others out.

I’ll post up my progress as I get working on it after I find the parts on Monday (either that or I get to extend my stay down here in Florida, which isn’t a bad idea 🙂 ).

[Archived]

So Jeff is going to send me the coils, will try those and see if that works. Also had a conversatoin with Liberty. They mentioned to try to pull the valves and “clean” them first before replacing. mentioned that they can sometimes get a little dirty and cleaning will take care of it.

Hopefully one of those two items will take care of the issue, as we need to move out spot on Friday morning, so need to be able to get the coach to ride height by then. if the coil or cleaning valve doesn’t work will probably need some more info on by-passing the system. Getting it level isn’t thatbig an issue as the spots are very level here, so really getting it to ride height is the main concern for me at this point.

[Archived]

Charles, when you pull the valve from the manifold be especially vigilant because on the bottom of each is a pair of O rings, one quite small and one a little larger. Sometimes they stay with the manifold, sometimes with the valve body. If you drop one or both they are hard to see and find.

[Archived]

Charles we trust you have the bus properly supported if you’re working underneath it or around the wheels.

[Ken]

Charles,

If you have trouble finding 12 coils/valves, let me know, I think I have one if your still at home.

[Archived]

Tom,

Thanks for the offer on the 12v coils. After speaking with Liberty and their parts guy questioning what I needed, he wanted to talk with Troy. I then called Jeff and jeff is sending me the coils. Also got the valves coming from Prevost (should be here tomorrow). Figured if I was going to take them off to clean and check them, it wouldn’t hurt to simple replace them.

Jon, your comment on keeping an eye on the o-rings made me thing it would be best to just change these out with new in the event I come across a valve with a bad o-ring.

Dick, All the work I am doing at this time is in the steer bay under drivers seat. So nothing under the bus. No reason to block/lift the coach. Thanks for the warning though. If it gets that involved, I will be calling in a service truck rather then do it myself here at the resort.

On a side note, I figured I would start the coach up and do some more investigation/trouble shooting this morning.

When I first got here, it was going to be for just a week. The spot I am in was open, but someone was coming in december 1st and asked for this spot specifically. So when I decided to extend our stay, I was told I needed to move one spot over. That means I had to have it fixed, or at least working by Thursday to move it (oh ye, the people coming in decided to come in early).

So when I started it this morning, I already had the switch in level/automatic position. Started the coach up, let it air up to 100psi and then turned on fast idle to let it fill the system. Once it purged the system at 130psi, I switched to ride position and the bus came up to ride height immediately. Checked the level low valves and none of them were leaking AT ALL!

Figured since it was up to ride height and not leaking, this was the best time to move it and then deal with the coils/level low valves when they come in later this week.

Even if I can’t get it to leak again, I will be replacing the level low valves and coils. Then we will have it at Jeff’s on the 11th and have him replace the Norgren spool valves around the coach as well as the ride height valves. Oh and it sounds like if I have the push fit hoses, replace those with the pressure fit hoses. Hopefully that will get me going on the air system refurbish.

Oh and as for the auto air dryer, I discussed this with Jeff and he confirmed that when the aux air compressor is on, the auto dryer should be spitting. so it sounds like it’s working properly and I don’t need to worry about it, especially since he put it on this summer.

[Archived]

Charles,

Jon, your comment on keeping an eye on the o-rings made me thing it would be best to just change these out with new in the event I come across a valve with a bad o-ring.

You can’t put new valves on without disburbing the “O” rings. The bigger one will probably fall off and the little tiny one may stay in place.

[Bryan]

Charles,

You will kinow if you have issues when you get to Jeff’s but here is some food for thought. This applies to all of us.

Sometimes for unknown reasons if a coach is unresponsive when we are trying to get the suspension to do something, such as go to ride height, or go up or down when leveling the problem can simply be a Norgren valve is getting the necessary air signal, but just has not responded by shifting the internal spool. The next time we try to do the same thing it works perfectly and we don’t know why. It is likely, but not always some crud (a scientific term) in it. If the system has ever had moisture the aluminum corrosion mixes with that moisture to create a paste and that can inhibit the operation of the valve.

But there is another possibility and that relates to the protection valve in the front. If the system has moisture that protection valve through which aux air passes when the brakes are at 75 PSI may have corrosion due to moisture and it is just not allowing air to pass in the volume needed. If that is the case a lot of stuff will not work as intended. Sometimes as Peter recommends beating on it with a big stick helps make that work.

If it is working now, leave it until you get to a spot where servicing it is more convenient for you.

[Corey]

tom, i was thinking the replacement vavle comes with the orings. if they dont, i will make sure to recover the orings from the existing valves.

[Ronald]

The replacement valves do come with new O rings.

[Archived]

getting ready to do some of this work today. what is the best way to drain the air system? there is a black nogren filter with a twist valve at the bottom of the filter just below the level low valve rack. will that work to purge the air? with the aux air compressor turned off of course.