Desiccant powder in air system - anybody else with this experience?

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Desiccant powder in air system - anybody else with this experience?

June 30, 2013, 10:06:03 pm

Quote from: indio192 – June 30, 2013, 01:10:04 pm

Found all valves to have a white coating that looked like talcum powder. I assume it is from the unmaintained desiccant. It easily wiped off.
Jim

It may be easy to wipe off but it is probably thru out the whole system.
When I saw it on a leaking check valve, I just replaced the valve.
I was unaware that I needed to clean it out of the tanks and hoses to prevent it clogging up the parts again.
I ended up replacing all the check valves and protection valves only to have to do some of them again.
Constant intermittent leaks.
I filled the tanks and bleeding them over and over again until it appeared clear.
Starting with the wet tank and then the front tanks.
I finally took each hose and blew them out.
I can only hope I got most of it out but I won't be surprised if I have to clean those valves again.
Here is a video of the dust coming out of the air tanks in spurts.

http://youtu.be/UPeObmkz8Tk

Re: Desiccant powder in air system - anybody else with this experience?

Reply #1 – July 01, 2013, 07:35:32 am

Well, it looks like my coach air system desiccant canister (Haldex) has failed and spread very fine desiccant powder throughout the entire air system.

See posting 2003 U320 HWH O-rings installed - no leaks

I haven't completed the verification, but this is the most likely cause for the talcum powder looking dust in my HWH solenoid valves (see attached photo).

Several people posted in that thread about having similar experiences with a failed Haldex canister. So, I thought it might be informative to hear from others who have had this problem.

What were your initial symptoms? How did you clean up the air system? What have been your long-term issues?

Jim

Re: Desiccant powder in air system - anybody else with this experience?

Reply #2 – July 01, 2013, 08:26:27 am

There is a synthetic fabric barrier inside the canister that keeps the desiccant beads within the inner shell of the canister. With age the beads can fail or the fabric barrier can fail and the desiccant is allowed to pass through into the air system as dust. The standard Haldex canister is rated for over 200 psi so higher air compressor governor settings shouldn't be a problem. I think the main problem is that the canisters are not being replaced in a timely manner.Gam

Re: Desiccant powder in air system - anybody else with this experience?

Reply #3 – July 01, 2013, 09:29:18 am

The desiccant filters in air dryers do NOT have an infinite life.

It is highly likely that checking back through the coach's history that at some point it went way too many years without service.

For me, 3 years is maximum.

Re: Desiccant powder in air system - anybody else with this experience?

Reply #4 – July 01, 2013, 10:03:24 am

Barry, where is the best place to buy your check valves and protection valves at a reasonable cost?

Re: Desiccant powder in air system - anybody else with this experience?

Reply #5 – July 01, 2013, 10:14:32 am

Sorry, I must not have been clear about my questions.

I know why mine failed - poor (no) maintenance by previous owners.

What I want to know is what people have done to remedy the mess created when a failure occurs. Barry posted a nice video showing what he did.

Is there anyone else out there that has had a Haldex (or equivalent) failure?

If so, what did you do to clean up the mess?

Do you really need to do anything or will time take care of it?

What are long term effects of doing nothing?

Jim

Re: Desiccant powder in air system - anybody else with this experience?

Reply #6 – July 01, 2013, 11:18:29 am

Quote from: indio192 – July 01, 2013, 10:14:32 am

Do you really need to do anything or will time take care of it?
What are long term effects of doing nothing?
Jim

As I mentioned earlier that powder is going to keep clogging up all the air line components causing valve failures etc.
After I replaced the Check valves etc without cleaning out the system it clogged the new check valves.
I don't think there is anyway around it. That powder has to come out or you will be fighting intermittent problems for awhile.
Start by bleeding the wet tank multiple times because that is where it hits first. Then each front air tank multiple times.
Cleaning the insides of the tanks would be preferable but so far I did not want to do that.

Re: Desiccant powder in air system - anybody else with this experience?

Reply #7 – July 01, 2013, 11:40:40 am

Thanks Barry for your info.

I just went over and talked with Mark Harvey. His take was there is little you can do to clean up the mess. He suggests the best method would be to start with the wet tank and blow it out as best as possible. Removing it and washing it out would be best, but not very practical for most DIYers.

While he had no first-hand knowledge about long-term issues, he guessed that you could minimize issues by keeping the system dry so the dust doesn't clump up.

I have to agree with your take - blow it out as best you can and then deal with the problems as they appear.

I did read on a trucker web site where a person replaced all his tanks, fittings, and hoses.

Jim

Re: Desiccant powder in air system - anybody else with this experience?

Reply #8 – July 01, 2013, 12:32:15 pm

Quote from: indio192 – July 01, 2013, 11:40:40 am

Thanks Barry for your info.
I have to agree with your take - blow it out as best you can and then deal with the problems as they appear.
I did read on a trucker web site where a person replaced all his tanks, fittings, and hoses.
Jim

After everything I did. The pressure is the best it has ever been. Several days now with almost no leakage in the leveling system.
Now to attack the leaks in the brake system which is turning out to be much harder as all the components are higher up in the chassis where I can't reach so I can isolate parts of the system. I need someone with 4 foot arms to help. (Phil Bostrom are you listening buddy)

Re: Desiccant powder in air system - anybody else with this experience?

Reply #9 – July 01, 2013, 05:38:14 pm

Barry, thanks for posting the video. Although I regularly (daily when on a trip) exhaust from the wet tank, I believe I saw the "white dust" coming from the DS front tank today; the other tanks seem fine. My leveling system does not loose air (knock on wood) but my air drains to zero within a few days, so I think I'll be doing some of the detective work you've been doing.
Grant

Re: Desiccant powder in air system - anybody else with this experience?

Reply #10 – July 01, 2013, 05:48:38 pm

Quote from: Grant L – July 01, 2013, 05:38:14 pm

Barry, thanks for posting the video. Although I regularly (daily when on a trip) exhaust from the wet tank, I believe I saw the "white dust" coming from the DS front tank today; the other tanks seem fine. My leveling system does not loose air (knock on wood) but my air drains to zero within a few days, so I think I'll be doing some of the detective work you've been doing.
Grant

Because I knew I had a system full of white dust I bleed the tanks directly and not from the valve at the wheel well. Better chance of getting more of it out.

Re: Desiccant powder in air system - anybody else with this experience?

Reply #11 – July 01, 2013, 05:59:52 pm

I had bleed valves installed in the front tanks (when they were installed 3 years ago the tech didn't mention finding any white dust and I had the air dryer/kit replaced then and last year as well, maybe I'm just seeing regular dust...); where do you bleed the air from for the wet tank (I use the valve at the wheel well)?

Re: Desiccant powder in air system - anybody else with this experience?

Reply #12 – July 01, 2013, 07:18:30 pm

Quote from: Grant L – July 01, 2013, 05:59:52 pm

I had bleed valves installed in the front tanks (when they were installed 3 years ago the tech didn't mention finding any white dust and I had the air dryer/kit replaced then and last year as well, maybe I'm just seeing regular dust...); where do you bleed the air from for the wet tank (I use the valve at the wheel well)?

Checking at the wheel well is fine if you don't see any powder. But if you do see any I would pull the line of of the rear wet tank and drain it directly to try and purge it there.

Re: Desiccant powder in air system - anybody else with this experience?

Reply #13 – July 01, 2013, 07:42:01 pm

Ok, got the coach back from the FOT shop late today so just finished removing the Haldex dryer cartridge.

When I opened the wet tank drain valve, a very tiny amount of white powder came out. If I would have blinked, I would have missed it.

Used a Vise-Grip chain wrench on the spin-on cartridge, but it still needed a little "convincing" to come off.

I was expecting a mess like the images on Barry's site (haldex_pure_air_plus_air_dryer_rebuild.htm), but it turned out to be not nearly so bad.

There was about a teaspoon of white powder on the surface of the Haldex unit (who knows how much had already leaked into the rest of the system). There was none on the coalescing filter nor in the coalescing filter cavity. In fact, the coalescing filter looked just fine.

I banged the desiccant cartridge on a table to see if any more white powder would come out. None did.

So, tomorrow off to FOT parts for a Haldex kit. Hopefully, I won't need both the minor and major kits.

Jim

Re: Desiccant powder in air system - anybody else with this experience?

Reply #14 – July 01, 2013, 08:09:36 pm

Jim,
Not to be the bearer of bad news but you need to at least pull the Turbo valve & clean it (located in the air passage where the governor ties in). Then all that is left to clean is the purge piston located on under the cover on the bottom and the check valve that is in the discharge fitting. You may not need new parts just clean & lube what you have.

Pamela & Mike

Re: Desiccant powder in air system - anybody else with this experience?

Reply #15 – July 02, 2013, 09:47:19 am

A Bendix video with some Q&A on Air Dryers

Bendix Tech Talk: Benefits of Oil Coalescing Technology

Re: Desiccant powder in air system - anybody else with this experience?

Reply #16 – July 02, 2013, 12:02:40 pm

Ok, time to buy parts. There are several of choices here. If I want to do a lot of detailed work disassembling, cleaning and reassembling, I could buy just the two filter kits - DQ6036 and DQ6032. But, since my time is so valuable

, I might be better off choosing the two rebuild kits - DQ6026 and DQ6020.

Here are some price comparisons for the two kits respectively:

FOT - $248/$91
MOT - $225/$96
Ryderfleetproducts.com - $121/$40

I would still have to do a good bit of detailed work including removing the entire Haldex unit (I checked mine and there is no way you can get to all the parts with the unit on the coach).

But there is still another choice. Thanks to information from Michelle, you can buy a refurbished Haldex unit from Napa. According to Michelle all the parts are new except the basic "frame". Napaonline price is $264. All you have to do is remove the old unit and install the refurbished unit. Yeah, it's $100 more than the two kits from Ryder, but, as I mentioned earlier, my time is so valuable.

Off to the Napa store here in Nac. They said it would be here first thing in the morning, and they only charged me $237!!!

Had to buy a set of BIG wrenches (a set of 5 BIG wrenches was cheaper than just 2 single wrenches) - $60.

Stay tuned for more, I hope.

Jim

Re: Desiccant powder in air system - anybody else with this experience?

Reply #17 – July 03, 2013, 02:01:51 am

Jim, I reported lots and lots on this dust issue over the last year.
Air Dryer desiccant contamination creates symptoms of air leak
Leaning Coach, Air Check Valves
Send me a pm and phone number if want to discuss the answer to your question of long term issues if you have not gotten that in this thread that I could not read in detail on this phone. You may have all you need but if not be forewarned it can give some unexpected and unpleasant consequences as it is solved.

You in Nac now?

Mike

Re: Desiccant powder in air system - anybody else with this experience?

Reply #18 – July 03, 2013, 10:28:55 am

I purchased a new Haldex, I think itwasfrom Amazon because I had to remove the old one to replace the desiccant. Well when I got the thing, felt how heavy it was and saw the location on my U280 I decided to have the folks at Mecca replace it. It took two mechanics to get it done. Decided the no BIG WRENCHES for me.

Roland

Re: Desiccant powder in air system - anybody else with this experience?

Reply #19 – July 03, 2013, 10:39:06 am

Replaced mine about a month ago. Piece of cake. No powder observable. Whew.....

Re: Desiccant powder in air system - anybody else with this experience?

Reply #20 – July 03, 2013, 01:59:41 pm

Quote from: indio192 – July 02, 2013, 12:02:40 pm

.............But there is still another choice. Thanks to information from Michelle, you can buy a refurbished Haldex unit from Napa. According to Michelle all the parts are new except the basic "frame". Napaonline price is $264. All you have to do is remove the old unit and install the refurbished unit. Yeah, it's $100 more than the two kits from Ryder.........................................

Jim,
I recently had good luck with the NAPA Remanufactured Unit @ $264. See my info post after Steve gave us all the recent "Heads-Up" info on the NAPA price:

Need to Replace Air Dryer

I could see no marks at all on my NAPA Reman. unit. It looked brand new! And the outside (Midland) markings on the sealed, pristine-new, shipping carton at Peterbilt looked identical to the Midland markings on the NAPA sealed, pristine-new, carton (which may mean nothing, I realize). It's just curious to see the price spread and I wonder if Midland-Haldex Remanufactures most or all of them?
BTW, how did you wrangle the additional $264 - $237 = $27 off at NAPA, you dirty dog, you!
Neal

Re: Desiccant powder in air system - anybody else with this experience?

Reply #21 – July 03, 2013, 02:08:28 pm

Ok, job all done - Haldex swap out in just 1-1/2 hours.

I guess I have to be a bit worried - the job went too smoothly. There's always a "gotcha", isn't there? Hopefully not in this case.

Here are some pics.

Refurbished unit looked virtually brand new. All replaceable parts were new, only the casing had been reused and it was repainted.

Swap was actually pretty simple. Fully lowered coach and drained all air (didn't see any white dust come out of wet tank this time).

A one person job as nothing is really heavy or particularly awkward (at least on my 2003).

I agree on Michelle's take where you just replace filters at next maintenance interval and then replace whole unit with another refurb the next interval. Not having to do all the detailed disassembly and reassembly required if you just did the two rebuild kits is worth the $100 price difference.

Now the question is "What is the maintenance interval?"

Mark Harvey says Foretravel is recommending 1 year intervals. Brett says he uses 3 years.

In my manuals folder there is a Haldex flyer that states "As a preventative maintenance, the coalescing filter should be replaced every 3600 operating hours - 100,000 miles - or 12 months."

Then there is this statement in the Haldex major repair kit instructioins:

"When servicing a Pure Air Plus Air Dryer that has been in operation for more than one year, it is recommended that the coalescing filter be replaced. If the dryer has been in operation for more than three years, it is recommended that both the coalescing filter and the desiccant cartridge be replaced."

So, both Mark and Brett are correct. Replace the coalescing filter yearly and the desiccant every 3 years. I think I will check the coalescing filter yearly, but not plan on replacing it unless I see carbon buildup described in the Haldex flyer. I will certainly replace the desiccant no less frequently than every 3 years.

Oh, if you do this job, be sure and check for leaks after you get it all pressured back up. Even though I was sure I had tightened everything really well , I still had a leak. Just took a little more elbow grease with the BIG wrench.

Jim

Re: Desiccant powder in air system - anybody else with this experience?

Reply #22 – July 03, 2013, 04:14:54 pm

Jim, Nice jop, you are fortunate that your dryer is so accessible, it is not that easy on a GV.
Gary B

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