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Topic: Newbie Tackles Bladder Manifold Air Leaks (Read 1071 times) previous topic - next topic

Newbie Tackles Bladder Manifold Air Leaks

Hi friends.  I'm working on air leaks in one of my two HWH bladder manifolds in the electronics bay. 

After studying the excellent posts by Rick Bowman...

HWH Slideroom Bladder Manifold repair/rework

and by Chuck Working On My Six Pack

...I dove in.

The first leak was in the manual shutoff valve and was easily resolved with a new 1/4" brass ball valve. 

The second leak is through the vent port of the air pressure regulator, part number HWH AP23204.  I disassembled and inspected the regulator and it is generally clean and I observed no debris .  The regulator diaphragm's rubber edge (where the diaphram seats against the lower body) -- while compressed a bit -- appears to be intact.  The spring is shiny and clean as is the interior of the housing.  The diaphragm seat has no observable scratches, etc.

Upon reassembly and back under pressure, the volume of air leaking out the vent port is much reduced -- perhaps 1/25 of previous volume?  There is some room for adjustment of the regulator's spring -- that is the spring in the top neck of the regulator that controls how much pressure is applied to the top of the diaphragm.  By increasing the spring compression I can further reduce the leak.  However, I'm hesitant to increase the spring pressure permanently without understanding how that impacts the bladder system.  Law of unintended consequences, right?

It would be nice to have air pressure gauges on the output side of the manifolds (I have 2 slide outs thus 2 manifolds).  Then I could see if the manifold that is not leaking is at, say, 12 psi, and the one that is leaking is at, say, 7 psi.  If I had that info I would feel somewhat more comfortable adjusting the spring pressure on the leaking regulator as long as the downstream air pressure did not exceed the pressure of the non-leaking manifold.

I'm on a waiting list for a call back from the HWH parts department to see if new regulators or rebuild kits are available.  I did not find the part number on their website.  Any thoughts on next steps?

Thanks in advance,
Mark
Mark Duckworth
2003 U320 4220
Build 6199, Motorcade 17971

Re: Newbie Tackles Bladder Manifold Air Leaks

Reply #1 –
U R doing just fine.  Have U checked the fittings on your aux air comp? 
Scott & Carol Seibert
2001 42' double slide U320 - Sold
Previous - 2002 36' U320

Re: Newbie Tackles Bladder Manifold Air Leaks

Reply #2 –
Quote from: Carol & Scott –
U R doing just fine.  Have U checked the fittings on your aux air comp? 
Well actually that's another issue.  I'll start a second topic so I don't hijack my own post!

Mark
Mark Duckworth
2003 U320 4220
Build 6199, Motorcade 17971

Re: Newbie Tackles Bladder Manifold Air Leaks

Reply #3 –
I'm working on the same problem. I've disassembled the regulator & burnished the seat in the base of the reg, it had a pretty good ring worn in it.
You might note that the inlet ball valve has a check in it, allows air into the manifold, but not out.
Dave W. (AKA Toyman )
'03, 270, 36', Build 6095, Pulling whatever I hook it to.

"Don't cry because it's over. Smile because it happened."
Dr Seuss

Re: Newbie Tackles Bladder Manifold Air Leaks

Reply #4 –
Quote from: toyman –
I'm working on the same problem. I've disassembled the regulator & burnished the seat in the base of the reg, it had a pretty good ring worn in it.
You might note that the inlet ball valve has a check in it, allows air into the manifold, but not out.

Dave,
I kept the check valve that was originally in the inlet air pipe string.  Mine looks like this:

tubing nut F-->M tubing adapter to NPT M-->F ball valve F-->M check valve M -->F manifold

The only item I replaced was the ball valve.

How did you burnish the seat? 
Mark Duckworth
2003 U320 4220
Build 6199, Motorcade 17971

Re: Newbie Tackles Bladder Manifold Air Leaks

Reply #5 –
Just got off the phone with HWH.  Previous regulator part number AP23204 has been replaced with part number RAP91414.  The manifold itself, #AP23200 has a new part number of RAP92177 and is north of $600.  Thankfully my manifold seems fine.

As a point of comparison FOT had the regulator in stock for $137.  Called MOT twice but got the parts dept. voice mail both times. Also in stock at HWH for $93 so I ordered it.  It ships with the 2 o-rings that go between the regulator and the manifold.

Has anyone put air pressure gauges on the output (bladder) side of their manifold(s)?  As a newbie I'm wondering -- is correct bladder inflation pressure important to prevent bladder failures?  Clearly I don't know much about this... just speculating.

Mark
Mark Duckworth
2003 U320 4220
Build 6199, Motorcade 17971

Re: Newbie Tackles Bladder Manifold Air Leaks

Reply #6 –
I have a pressure gauge in the rubber bladder hose for the bedroom slide.  I used a barbed "T"  with female pipe thread in the middle
and 2 hose clamps.  Easy.....................but I also put in an inspection opening in the trim piece under the closet for viewing things.

Bladder problem ..strange to say the least

I have another gauge and fittings to attach it to the bladder side of the manifold but I haven't put it on yet.

Re: Newbie Tackles Bladder Manifold Air Leaks

Reply #7 –
I can not say for the old manifolds but the new one is good up to 16lb of pressure to the bladder(keep in mind my manifolds and bladders are new). Not sure how much pressure the old bladders are good up to.

Good job. Tom on the board has rebuild kits for the valves (dont remember his user name or if the rebuild kits fit this manifold).

Pretty cheap

Re: Newbie Tackles Bladder Manifold Air Leaks

Reply #8 –
Quote from: DavidS –
I can not say for the old manifolds but the new one is good up to 16lb of pressure to the bladder(keep in mind my manifolds and bladders are new). Not sure how much pressure the old bladders are good up to.

Good job. Tom on the board has rebuild kits for the valves (dont remember his user name or if the rebuild kits fit this manifold).

Pretty cheap
The rebuild kits do not fit the air regulator.  See: reply 13 and 14 here: HWH Slideroom Bladder Manifold repair/rework 

Dan - Full timing since 2009
2003 U320 40' Tag 2 slide

Re: Newbie Tackles Bladder Manifold Air Leaks

Reply #9 –
Today I discovered that the normally open solenoid on the bottom of the aux compressor's water trap sometimes does not close, and when it does close it stays slightly open.  Thus the aux compressor has to work a little longer to get to cutoff pressure. 

Has anyone successfully serviced this solenoid?  Also has anyone routed the output of this water trap to the exterior of the coach to keep the moisture level down in the electronics bay?

Thanks,
Mark
Mark Duckworth
2003 U320 4220
Build 6199, Motorcade 17971

Re: Newbie Tackles Bladder Manifold Air Leaks

Reply #10 –
Quote from: Mark Duckworth –
Today I discovered that the normally open solenoid on the bottom of the aux compressor's water trap is sometimes does not close, and when it does close it stays slightly open.  Thus the aux compressor has to work a little longer to get to cutoff pressure. 

Has anyone successfully serviced this solenoid? 

It's a common issue.  We always carried a spare, and Steve did rebuild at least one.  It should be somewhere on the forum, either under his ID or mine.  I'll try to find it but you might want to search at the same time (two heads searching being better than one).

IIRC the bowl is notorious for developing hairline cracks where the fitting for that solenoid valve attaches.  Unlike the desiccant bowl, I believe it is difficult to find the one with the fitting for the solenoid valve and you might need to order it from FOT.
Learn every day, but especially from the experiences of others. It's cheaper!  - John C. Bogle

2000 U320 36' non-slide / WildEBeest Rescue
2003 U320

Re: Newbie Tackles Bladder Manifold Air Leaks

Reply #11 –
Continued troubleshooting the aux compressor drying chain (trap, dryer, filter, solenoids, etc.).  The water trap is rusted out / ruined, water trap solenoid stuck partially open and frozen, coalescing filter also shot, aux tank to wet tank solenoid stuck partially open and the pop off valve inoperative.  Add all that to last week's discovery that the desiccant dryer assembly and bladder manifold air regulator are bad and you can see why I've spent the last few days inside the electronics / aux air bay.  Sheesh! 

Rant warning!

I'm happy that the PO over-maintained the engine with oil and filters every 3k to 5k miles.  I'm thrilled that the paint is shiny and furnishings are as new.  Super happy.  But I wish he'd paid a little attention this area.  You might recall during my recent PPI that there were over 2 quarts of rusty water in the aux air tank when drained.  I now understand why.  This also explains the surface rust in the electronics / aux air bay.  The compressor was running overtime and leaking hot, undried air like a sieve.

End of rant!

Oh well.  All's well that ends well.  I strongly prefer keeping the coach as close to OEM as practical, but in this case have decided to go a different direction.  I apologize in advance if I offend any OEM purists: I've ordered a non-OEM 4-stage desiccant dryer system for the aux compressed air system.  It holds 2 quarts of desiccant and should only need maintenance about once a year.  I plan to install it with automated water trap purging (like the OEM design) that's vented to the exterior of the coach.  Also considering replacing the solenoids for the aux air to wet tank and the water trap dump with aftermarket solenoids that are affordable and easily obtainable. 

Mark
Mark Duckworth
2003 U320 4220
Build 6199, Motorcade 17971

Re: Newbie Tackles Bladder Manifold Air Leaks

Reply #12 –
Quote from: Mark Duckworth –
You might recall during my recent PPI that there were over 2 quarts of rusty water in the aux air tank when drained.  I now understand why. 

Mark,

Not knowing how long the coach sat with all that water in the slide bladder tank, keep an eye out for rust-through on the tank in the future. 

Learn every day, but especially from the experiences of others. It's cheaper!  - John C. Bogle

2000 U320 36' non-slide / WildEBeest Rescue
2003 U320

Re: Newbie Tackles Bladder Manifold Air Leaks

Reply #13 –
Mark, do you have a link for the 4 stage dryer? Thanks.
Richard & Betty Bark & Keiko our Golden Doodle
2003 U320T 3820 PBDS
Build # 6215
MC # 16926
2016 Chevrolet Colorado 4X4 diesel

Re: Newbie Tackles Bladder Manifold Air Leaks

Reply #14 –
Mark,
I have spent the better part of a year ( just paid registration renewal) repairing and replacing, updating and so on.. kinda takes its toll.. when you crank that engine and hit the drive button all those hours fade away and it's just you and the open road.. when you get to camp or stop to rest you will start to love this thing and all the work you have done to upkeep and make it yours.. at the end of the day it's only money and your learning valuable lessons from the repairs. I will expect a new thread after your first use and how much fun it was.. when you return home it will be the same thing with trying to get the repairs finished and the upkeep but I must warn you.. it never stops!! And it keeps you young.

Not sure what my wife would do with me on the weekends if I wasn't working on
My motorhome... I shudder to think about it 😅

Re: Newbie Tackles Bladder Manifold Air Leaks

Reply #15 –
Quote from: rbark –
Mark, do you have a link for the 4 stage dryer? Thanks.

R&B,

Here's the dryer.

and I ordered the filter kit to have on hand for service.

I purchased it on eBay and it came with 1 gal of color indicating desiccant.  When I used to work in a research lab we had a vacuum oven that was really effective at rejuvenating saturated desiccant.  I've never baked it in a conventional oven but apparently that's the common method.

Mark
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Mark Duckworth
2003 U320 4220
Build 6199, Motorcade 17971
 

Re: Newbie Tackles Bladder Manifold Air Leaks

Reply #16 –
Quote from: DavidS –
... at the end of the day it's only money and your learning valuable lessons from the repairs...

...but I must warn you.. it never stops!! And it keeps you young....

David,

Thanks for the encouragement.  My job these days is very process oriented and it's nice to have tasks that, once accomplished, give me a sense of completion.  If I seem frustrated by the time, work, or money then I'm not expressing myself well.  I'm having fun doing this.  What got my dander up is that the PO didn't take care of such a fine piece of machinery.  I've never understood that.

Regarding these repairs, early in my career I worked in a research environment with gas systems and plumbing for instrumentation in lab environments.  One of our field projects was a national study of fugitive hydrocarbon emissions meaning we identified and quantified gas leaks in production facilities.  So leak chasing doesn't faze me.  It's just the application that's new.  As Roger wrote so aptly above, perfection can indeed be the enemy of the good. 

First camping trip is this Friday night.  I'm going with some guys from church to a campground in the Appalachians.  Should be a great time. 

Mark
Mark Duckworth
2003 U320 4220
Build 6199, Motorcade 17971