I have been dealing with the same intermittent air leak for some time.
I installed several ball valves to isolate the leaking line.
After closing the ball valve to line 50 to the front manifold the leak stopped.
I cleaned the 6 pack solenoids and replaced the "O" rings.
Sprayed everything for leaks with no luck.
My air line diagram was not matching up to reality so I went back to Colton Truck to get some help on tracing every line so I could have a correct diagram.
I spent another day under the coach with the tech tracing every line and updating my diagram to the new info.
We air pressure tested every line on the front manifold and they all tested good.
Tested all the way to the check valve on the air tank which was previously replaced and assuming it was good.
Found it was leaking. I reminded them that it was replaced by them recently.
They took it apart and found contamination in it.
A white powder, as we dug deeper we found the powder in the wet tank, front and rear tank, as we blew out the air line to the Retarder accumulator to determine which line it was on the diagram it was coming out there to.
Removed the air dryer which was good but found some powder in there also.
It appears the white powder was caused by the desiccant in the previous dryer disintegrating and was passing through the system as a white powder.
As i looked back on my records I remember replacing the air dryer one time that was way over do because I had overlooked it somehow.
It was a mess when they replaced it but I had no idea what had already happened to the lines.
So the powder was intermittently causing the check valve to leak which was giving me erroneous info.
I had seen the powder inside all the check valves which is why I replaced them but having no idea what it was and just chocked it up to moisture caused by the aux compressor coming o so much.
I also replaced the protection valve as it looked pretty corroded with that powder also.
At this point I don't think there is much I can do about it and will probably be facing these intermittent leaks in the future.
The tech mentioned there really is no good way to get it all out. I can try to blow out each and every line but no way to get it all out. :(
I don't remember reading on the forum anything like this so let me be the first to say watch your air dryer and replace it on time.
Ugh! Russell had posted some good photos a few years back after having his air dryer powder "migrate" (and given me nag-munition to keep on top of ours :)) ) Pure Air Plus Air Dryer - An Ounce of Prevention... (http://www.foreforums.com/index.php?topic=7700.msg58579#msg58579)
Good discussion about the new DA33200 replacement (if you go remanufactured/replacement rather than a rebuild kit) in this thread Haldex air dryer isolation valve (http://www.foreforums.com/index.php?topic=17590.msg118237#msg118237) with some really good history from BJ.
-M
Barry, I wrote some time ago about the white powder (clay I think) and warned...change the desiccant filter regularly, watch this system for its failure causes list of misery.
To review: the prior owner did not change timely is my interpretation. In any case, leveling was not maintained and raise function on front had some problems as well. You could see white material vent when I would test the drain on the four tanks. I got Haldex to suggest solutions, which I reported...so if this new to you, it involved cleaning the wet tank.
Over six months we found impacted and had to replace three check valves, three solenoid s, two regulators and two ride height valves (maybe unrelated to the material that i characterize as clay desiccant). "Clay" had coated the check valves such that could not clean them. Particles got into solenoid, other valves and cylinders. Over this time I would check the exhausting of the tanks and at times see clay dust blow out. In time that stopped. Hope this helps emphasize this for someone, save you a problem.
Mike
After I got home I found my D/S front air bag would not raise when I hit the front raise button or the coach raise. Trying to figure out how to get it raised so I can get underneath to check it out. I can hear the solenoid clicking when I hit the front raise button but it is not letting air into the bag. So it has to be in the manifold. I can't get out of my driveway without raising the coach all the way without ripping out the radiator. Got to leave Thursday AM.
Here it starts piece by piece. How did they suggest you clean the wet tank? I would think that the front 2 tanks would need it also as the powder has progressed throughout the system infecting all the check valves etc.
Barry, wish I knew how to find my prior post but recall Haldex was very particular about what to not use. I reported Haldex instructions to MOT and they disconnected the wet tank and washed it out with soapy water, no solvents besides water as I recall. Haldex was very understanding, anxious to help, said it not a unique inquiry.
Isaac did the work, ran air to dry, reconnected system and said it helped a lot but as you said clay still throughout the system. We operated a few weeks, put in new filter, ran a while again and found more clay dust, so changed again.
I then came to realize that air was moving incorrectly between the front tanks so Isaac worked there and found all three check valves coated such that could not really even scrape the material off easily. After those replaced, and those solenoids and regulators along the way, they got the system to working as it should.
Later Keith Risch drove, was not pleased and found two ride height valves not working properly. I do not know if those related to the clay.
I was quite frustrated and perhaps impatient with the clay but they worked on it until got it right. It took several months and efforts. I just should have been as concerned about the prior maintenance on this system as of the liquids and those filters. I would liked to have avoided this lesson!
Mike
In reply to pm, may be of interest....Haldex may have thought it good to remove the connection to the other tanks and wash and dry them but they left it at the wet tank to clean so that is what MOT did.
As for the lines, the general dealer manager suggested removing those but service folks said no.
Separately to add in case you wonder, the clay dust continued to circulate and build in the filter so we replaced the filter after a thousand miles as we worked thru this over months.
Don Hay told me that he had heard of almost a slurry coming from the wet tank when you open the drain valve. Perhaps he can clarify if i reported him wrongly. I did not see that, only air and powder blew out. But perhaps at one time I had that? The coating on the check valves was so tight you could barely even scrape some off. I did see clay dust out a front air tank drain valve.
Hope this clarifies. Mike
Colton Truck service manager & I checked the air dryer which has 8500 miles on it ( 1 year) and it looked new.
I did not hear that either. I saw powder blow out of front tank, and the line to the accumulator when I blew air thru it tracing the air lines to correct my air diagram.
That is what I am seeing also. see photo.
I tried again to get the raise to work and this AM and it did. I am going to pick up a pair of Bottle Jacks in case I run into this again. If I cant raise it I cant get underneath to work on it ???
Slight correction: It wasn't that I "heard". It happened to me! Within a couple weeks of buying my coach (May, '03), I read that I should check the wet tank frequently, so I did: I wasn't prepared for a greyish fluid the viscosity of honey (but not sticky) to pour into the palm of my hand. I brought it to the attention of the FOT Service Manager (Brad Laidler), who just about lost it (they had just signed off on a 6 month, 6,000 miles bumper-to-bumper warranty). They fixed it promptly. At the time I didn't realize that it was liquified Drierite. I would probably have had a cow had I understood the significance..
What causes failure of the desiccant in the dryer ? Does the dissacant get so saturated that it expands and burst the inside of the canister ? Or is the filter faulty to begin with ?
Gary B
Was it the air dryer filter that was replaced or is there a filter within the air system?
Air does not circulate through the air dryer. Fresh air comes in from outside, through coach air filter, through turbo, into intake manifold, to air compressor, then to air dryer. Air is always being expended through leaks, ride height & level lowering coach, and brakes.
But it looks like the white dust hangs around a long time, causing a mess on its way back to the atmosphere.
It looks like we will be letting a little air out from our wet tank on a regular basis, like checking oil level and coolant level. Also a quick drain on the two front brake tanks, but less often.
At the very first sign of white powder from air tanks, air dryer filters will be replaced, in addition to changing it about every two years. Would be nice to catch this problem as it just starts. We have changed the two air dryer filters ourselves before. It goes quite fast after dumping all air pressure from system. We don't change the brass pressure release valve on the bottom very often.
Glad you got your coach to raise today Barry.
Looks like I will be able to leave tomorrow as I got the coach raised. I found that white dust on the solenoids also. I have some spares that I use as I take some out to change the "O" rings. I am putting the solenoids in white vinegar and it looks like the powder is being dissolved. I will use them again to replace existing ones to clean them.
I'm confused .I though all the compressed air for the air brakes and leveling system passed through the dryer on it's way to the wet tank?Gam
Gam,
You're right. I don't think Barry is being conservative enough. I change my drier according to FT's recommended schedule, which is every 18 months. If I ever saw moisture in the wet tank, I'd change the drier immediately.
You are correct, output of compressor is the air dryer, then dry air goes to wet tank. Both brake tanks get their air from the wet tank. All air brakes & accessories, like leveling, etc get their air from brake tanks.
When it was said air does not circulate through air dryer, it meant that air from all tanks does not circulate back to air dryer. Only new fresh air enters air dryer, so air contaminated with clay dust in the system does not continue to contaminate a new air dryer filter. So there would be no reason to change air dryer filters more often after changing them because of finding clay dust in the tanks.
But the air dryers job isn't to filter the air. The air supply for this system comes from the engine intake manifold . The dryer does have a small filter that is to remove any contaminants picked up after the main engine filter.The job of the air dryer is to remove water and oil vapor from the system. The reason to change the canister is to replace the desiccant. Most times silica gel is used for adsorption ,but some types of clay can be used.I'm thinking this clay dust is the desiccant from a canister that was damaged or in service to long.Gam
In my case that is what happened.
I waited to long to replace it. Since I did not see moisture at the petcock I mistakenly thought it did not need to be changed at that interval. Expensive lesson in time and $$$ :(
Where can you get just the Oil rings for the 6 pack Air Solenoid Valve ?
Crazy J,
From HWH. Part number RAP 6554 (6 large O-rings and 6 small O-rings). $8 per package.
Grainger or Ace Hardware carries them also.
They are both 1/16 wall O rings, # 15 (.691OD) and # 28 (1.504OD)
HWH Leveling Valve (http://www.irvblog.com/foretravel%20projects/Ride-Height-Valve/)
You can also disassemble the valve and there is another o ring inside the valve. I went to a hydraulic shop with all 3 o rings and they had a guage to check the sizes and I got enough to do 2 6 packs for about $7.00. It was a little tricky to get the valve apart, but by using 2 of the nuts that hold on the coils and locking them together was able to disassemble. After I did that the coach no longer leaked down.
Thanks Rudy, Barry & Red Tractor.
For the information on the O-Rings.
You will find several threads in the past where I wrote of desiccant dust from the Haldex getting into the air brake and level system and causing havoc. I reported everything from coated check valves to contaminated solenoids and means to address, plus the symptoms of such problems, mostly related to leveling and ride height control.
In recent months we thought the problem resolved and then I had a Travel mode lean problem with the engine off after installing air bags. I also reported dust had actually come to accumulate in the air bags and might puff out when making a rapid change from Raise.
The latest: I hope this is the final solution. I am sure you check the wet tank drain valve often for dust but I have had people ask me what that was about and where it was, so I know some may not know of it. I was told some dust would be normal. So its frequent appearance was not a great alarm.
In the latest, Keith Risch became puzzled about an aspect of this leaning and still frequent dust and decided to remove the wet tank. Over a year ago we had washed it per Haldex process. This time Keith and Mike applied external air pressure to the removed tank and covered the shop up with dust....they had to run to close coach doors. Fine dust was blown out. They learned that large deposits had continued in that tank regardless of the work done before. The small puffs when I would open the valve only showed the larger problem, it did not really drain the dust.
The solution? They worked the tank with CLR and did inspections after that cleaning. They are convinced this now removed all the dust, lots of it, and then went to work on air lines. So if you have a problem with the dust after you think all was clean, consider a new tank or this possible option to clean the tank. I think it rare you will need this, but if it happens, this information may be helpful.
Mike
Michael: Considering all the time and expense involved in cleaning this dust out of a contaminated air system, I wonder if it would not be more economical to just go directly to tank replacement? Especially in the case of the wet tank, which probably contains the greatest percentage of "wandering" clay dust. Those tanks are not that big - I would think it would be pretty easy to locate a suitable off-the-shelf replacement. Even if it had to be custom fabricated, seems it would be cost/time effective to start the decontamination process with a brand new, CLEAN, wet tank.
Just the idle musings of a "armchair quarterback", who hopes to never have to deal with this problem.
Would it be feasible and logical to install an additional appropriate filter after the dryer? THANKS JC
Oh for sure chuck! Yes! Just should have been done a year ago. No one thought of a new one as the tank was washed out a year ago and thought that removed from the equation.
We have learned to not overlook this option of that tank remaining the cause of air leaks or mismanagement. I was seeing a periodic and continuing supply of dust even after the tank was rinsed a year ago.
One may have identified and solved a dust problem without having to do this. For a long time each fix of a solenoid or valve etc was thought to be the last for us, that the dust had worked its way out of the system. It had not, a huge supply remained. Try the tank clr clean or a new tank if dust continues.
Thanks,
Mike
Actually, just servicing the dryer every 3 year or so will prevent 90% of the issues. Failure of a dryer that has been serviced is very rare.
In my opinion, replacing the tanks should be far cheaper than paying a tech $100+/hour to clean them. On my coach, the three tanks are all identical. While I could not find a price for our JWP tanks on the Internet (I'm sure Mike Grimes could give you a price), similar tanks sell for $100 or so.
Since I had nothing better to do, I cleaned my own tanks. It was a messy job, but didn't cost me any real $.
Cleaning the tanks required removing all the fittings. To replace the tank, all you would need to do extra would be remove 4 bolts, pull out the old tank, put in the new tank, and replace the 4 bolts. Pretty simple. The tanks are not very heavy.
Jim
Rebuilding the air dryer isn't difficult at all, and it's not expensive if you order the parts online. I can research what I paid for all my rebuild parts if anyone cares, but it was way less than replacing the air dryer as I recall. The difficult part, at least on my coach, is getting the air dryer out of the coach and back in again. If you can do that you can rebuild the air dryer in no time. On my coach it's located up high in the passenger side rear corner of the coach. I have long arms but it was still a stretch for me to get to it. It's a little bit heavy too, especially if you're holding it up there a long time trying to get it back into the clamp rings. Look at the dryer and realistically estimate if you'll be physically able to get it out and back in again before you even start the job. If you can do that you'll have no trouble rebuilding it. If you can get some young whippersnapper with long arms to take it out and put it back in after you rebuild it you'll be even better off. :)) My air dryer is probably the original, which is to say well over 20 years old, and I doubt it had ever been rebuilt. My coach has low mileage on it though and the air dryer is only in use when the engine is running. I don't know how that affects the service interval, if at all? The only problems I found with my air dryer were the rubber exhaust hose was so deteriorated that it had fallen apart and oil was blowing everywhere when the purge valve released air, and the little check valve inside the air dryer had disintegrated and obviously wasn't working anymore. I don't know how the failure of the check valve affected the performance of the air dryer but I presume the manufacturer installed it for a reason, so I replaced it with a new one, along with a new purge valve, desiccant canister, o rings, and everything else except the electric heater and thermostat, mainly because I didn't have a soldering iron with me at the time, but I still have those parts if I do need to replace them. I didn't see any signs of white powder escaping in my system. My main point here is that it's a lot cheaper and only slightly more difficult to rebuild your air dryer instead of replacing it. You're still gonna have to get the old air dryer out and back in again, and that's by far the most difficult part on my coach. Hopefully other models have the air dryer located in a more easily accessible location. The actual rebuild part is really easy so have no fear of that.
For those with the Haldex air dryers, it's actually just a little bit more expensive and a whole lot easier to just buy a reman'd air dryer from NAPA
Desiccant powder in air system - anybody else with this experience? (http://www.foreforums.com/index.php?topic=18448.msg126847#msg126847)
I second what Michelle said.
It was duck soup to simply replace the entire Haldex unit on my 2003 with a reman unit from Napa.
My post describing replacing the Haldex:
Desiccant powder in air system - anybody else with this experience? (http://www.foreforums.com/index.php?topic=18448.msg126969#msg126969)
Instead of rebuilding my air dryer I purchased a new on on the web. My reasoning was, if I had to take the old one out to rebuild it, I may as well buy a newer model and just install it. RRadio says it is a "bit" heavy, you better believe it. After lifting the thing I decided to have the folks at Mecca install it. I watched while TWO technicians installed the new dryer, and said to myself , "good decision, Roland".
Roland
Could be the one that's on the older coaches. On ours, I held the Haldex dryer in place (wearing my pink leopard print Mechanix gloves) while Steve made the connections. He can tell you I'm not exactly "strong like bull" ;)
I also was the one to take the old one back to NAPA for the core charge refund...
Could be the one that's on the older coaches. On ours, I held the Haldex dryer in place (wearing my pink leopard print Mechanic's gloves)
I sure would have liked to have been the to see you in your gloves !!!
My air dryer is the Bendix AD4 and I probably saved at least $100 by rebuilding it instead of replacing it. I didn't think it was particularly heavy except when I had to hold it way up there a long time to get the clamp rings around it when I put the air dryer back in. That's why I said to look at it first and realistically estimate if you'll be physically able to do the job before you even start... I'm sure you can rebuild the air dryer if you can get it out and back in. I have have confidence in you! ^.^d