Rust inside airbags

[John C]

I am in the process of changing 10 airbags, noticed two airbags has rust inside, also a few airlines has rust to.

I know I need to change the air dryer, how about the airlines with rust in it? am I supposed to change that too? is anything I need to check besides that?

Please advise.

Thank you.

[Ivan K]

Wow, getting the system clean is going to be a nightmare unless the moisture came from leveling compressor and did not backfeed into the whole brake system, that would be lucky. Still painful to see though. 

[John C]

1 minute ago, Ivan K said:

Wow, getting the system clean is going to be a nightmare unless the moisture came from leveling compressor and did not backfeed into the whole brake system, that would be lucky. Still painful to see though. 

Wow! I didn't realize it is that serious!

How do I explain that only two bags has this problem? does that means it rust is only in a certain area? how do I check if the brake system is rusted or not?

Thanks!

[Ivan K]

Only two bags, I suppose there would be a theoretical situation when only those two bags on same axle end needed aux compressor air to keep level. Or were they already wet when installed. Good thing they seem dry, where did the moisture go... I would probably remove a hose or looked into a valve on a main tank to check and see. Uncharted territory for me.

[vito.a]

Just clean any lines or fittings you're working on and service the dryer. 

That's about all you can do.  

[John C]

Both were on the front passenger side, losing all air in a couple of days.

I will follow the airlines tomorrow.

Thank you

[TomV48]

WOW.  Sitting here in So Cal feeling so smug that that can only happen in a wet climate.  Yikes you are here too.  Here is what my book says

"Regeneration - The mild backflow of air through the air dryer and out the purge valve that begins
immediately after the purge and lasts normally 10 to 15 seconds. This backflow of air, from the
air system and through the air dryer, removes moisture from the desiccant cartridge and
prepares the air dryer for the next compressor load cycle."

We have had the coach for over four years and I just changed our desiccant cartridge last year.   Old maintenance records do not tell me if it had ever been done.

My book says every 2 to 3 years, when compressor is changed or if there has been water in the tanks.

Two years ago I found the air/water release valves and never so much as a wisp of moisture.   I guess I have been lucky

 

 

Edited May 14, 2024 by TomV48
typo

[John C]

16 minutes ago, vito.a said:

Just clean any lines or fittings you're working on and service the dryer. 

That's about all you can do.  

How do you clean the airline? Maybe it take less time to just replacing it?

6 minutes ago, TomV48 said:

WOW.  Sitting here in So Cal feeling so smug that that can only happen in a wet climate.  Yikes you are here too.  Here is what my book says

"Regeneration - The mild backflow of air through the air dryer and out the purge valve that begins
immediately after the purge and lasts normally 10 to 15 seconds. This backflow of air, from the
air system and through the air dryer, removes moisture from the desiccant cartridge and
prepares the air dryer for the next compressor load cycle."

We have had the coach for over four years and I just changed ours last year.   Old maintenance records do not tell me if it had even been done.

My book says every 2 to 3 years, when compressor is changed or if there has been water in the tanks.

Two years ago I found the air/water release valves and never so much as a wisp of moisture.   I guess I have been lucky

 

 

I already bought a new air dryer.  Will replace it Thursday.

 

[TomV48]

john I missed my point.       Is your system blowing off pressure through  that system after you come up to full pressure and do you blow off air from the Spit valves once in a while.   I think the book says purge water from air tanks drain valves monthly more or less depending upon humidity 

[John C]

1 hour ago, TomV48 said:

john I missed my point.       Is your system blowing off pressure through  that system after you come up to full pressure and do you blow off air from the Spit valves once in a while.   I think the book says purge water from air tanks drain valves monthly more or less depending upon humidity 

Yes, now I remember I read that on the manual a while ago, that is definitely another to do.

Thank you.

[jacwjames]

Just a question

Do you have a small compressor that keeps the coach level while parked.  If so does it have any type of air water separator or way to condition the air.  Does it have a way to drain water?? 

I think that the front main tank has a wet and dry side that has a check valve internally.  Not sure how a small compressor ties into the air system.

 

[Dr4Film]

The HWH Aux Air leveling Compressor has a small air dryer built into the system. However, I think the 2007 Dynasty uses the Valid Air Leveling System which I have no idea whether it came with an air dryer or not.

[John C]

1 hour ago, jacwjames said:

Just a question

Do you have a small compressor that keeps the coach level while parked.  If so does it have any type of air water separator or way to condition the air.  Does it have a way to drain water?? 

I think that the front main tank has a wet and dry side that has a check valve internally.  Not sure how a small compressor ties into the air system.

 

It has been parked at my house for the last 4 months since I bought in AZ, there is a the auxiliary tank in the back on P.S side, no sure if it is also responsible for the front, the fuse was bad when I checked, after I replaced the fuse it only ran a few times. but not very long, I was going to change airbags & rebuild 6 pack first , so this was put on the back burner.

 

48 minutes ago, Dr4Film said:

The HWH Aux Air leveling Compressor has a small air dryer built into the system. However, I think the 2007 Dynasty uses the Valid Air Leveling System which I have no idea whether it came with an air dryer or not.

When I rebuild 6 packs and 4 pack, I noticed there were quite bit rust inside it too. but not as many as the two airbags. I was wondering where there are coming from at that time.

Looks like the rust is definitely in the system, no sure why the other 6 airbags don't have any rust in it?

 

[Paul J A]

Bet the desiccant filter was never changed. 

[John C]

29 minutes ago, Paul J A said:

Bet the desiccant filter was never changed. 

Bet a lot of things were never changed! I am surprised the original airbags last so long!

[Frank McElroy]

On 5/14/2024 at 9:38 AM, Dr4Film said:

The HWH Aux Air leveling Compressor has a small air dryer built into the system. However, I think the 2007 Dynasty uses the Valid Air Leveling System which I have no idea whether it came with an air dryer or not.

Likely your 07 Dynasty does not have an air dryer on the aux air pump.  You would need to look at it to be sure.  On my coach, the auxiliary air pump does not have an air dryer.  That's why when I auto level, I shut off the Valid/HWH system - I don't want water vapor in my airbags.  Luckily my coach stay level for months.  I also removed the auxiliary air compressor CB to prevent it from running.

[96 EVO]

12 hours ago, Frank McElroy said:

Likely your 07 Dynasty does not have an air dryer on the aux air pump.  You would need to look at it to be sure.  On my coach, the auxiliary air pump does not have an air dryer.  That's why when I auto level, I shut off the Valid/HWH system - I don't want water vapor in my airbags.  Luckily my coach stay level for months.  I also removed the auxiliary air compressor CB to prevent it from running.

Suppose that's why Valid provided the small tank, expecting the moisture to condense and remain in there.

[Frank McElroy]

43 minutes ago, 96 EVO said:

Suppose that's why Valid provided the small tank, expecting the moisture to condense and remain in there.

That's right.  That small tank also has a separate drain valve.  On my coach with the small tank mounted on DS frame rails, the drain valve is located next to the rear main tank valve at the rear engine bay.

[96 EVO]

Anyone not draining that little tank frequently, should be!

[Ivan K]

I would think the HWH dryer and auto drain would be very easy to duplicate in very humid climates. Possibly might need a check valve if the only backflow prevention is in the compressor head.

[96 EVO]

Yep, that's where the only backflow check valve is.

I found that one thanks to Frank's exploratory surgery 👍!

[John C]

I am suspected inside the staging tank is rusted.

I only used the auxiliary compressor once, it is located on the  passenger side next to the driver wheel. no sure how many auxiliary compressors I have, unless my coach have four (I guess it is very unlikely) otherwise it is very hard to explain why only the two airbags in the front has rust inside.

I traced from the front Valid 6 pack manifold, it has a two 1/4" airlines each goes to left & right, on each side, it goes into a small staging tank first , from there,it has two 3/4" airlines goes out to the two airbags on each side in the front.

So there are two possibilities

1) The inside of staging air tank on the front passenger side is rusted

2) The 3 air lines on the front passenger side has rust inside.

It could be both and the rust most likely coming from the staging air tank

Because I have so many thing to work on right now,I will come back and replace the staging air tank (need to find out the air tank model #) when I have more time.

 

[Frank McElroy]

Those "staging" tanks as you call them are actually called Ping tanks.  Their purpose is to increase the air volume of the front air bags for a softer ride up front.

[96 EVO]

I think you are looking at susspension 'ping' tanks!

Frank will know.

{edit} He was already on it!

Edited June 17, 2024 by 96 EVO

[John C]

Just now, Frank McElroy said:

Those "staging" tanks as you call them are actually called Ping tanks.  Their purpose is to increase the air volume of the front air bags.

I see, I will need to get a replacement on that one, it is possible that this one cause my stubborn air leak on the front passenger side, but I just could not find any leak either with soap water or leak detector on the Ping tank.

After I replaced all air bags & rebuild 3 Valid manifold, I fixed all air leaks except the one on the front passenger side, now on the 3 side the air stays in the air bags for weeks without any leak but the front passenger airbags leaked out all air in one night. I then swapped the front 6 Packs with the rear 6 Packs, the result is still the same, only the front passenger side leaks, so the 6 packs is not the problem, the only possibilities is again the airline from 6 pack to ping tank ,from the Ping Tanks to the two airbags.