Author Topic: Airing up problem  (Read 3993 times)

Fred Cook

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Airing up problem
« on: April 07, 2018, 12:58:28 PM »
My driver side airs up very.. very.. slowly while the passenger side comes up normally. The coach appears extremely lopsided for about 10 minuets until the drivers side starts to catch up. But.... the drivers side never airs up all the way, stopping about 2 inches below the passenger side.  So... the coach is traveling down the road in a noticeable lopsided position.  Any thoughts why it is slowly airing on the driver side and not airing up completely?
Fred & Cindy
2002 Beaver Patriot Thunder 455, C12 CAT
Towing 2019 Chevy Equinox, AWD Diesel
South Central Missouri, US Army Retired

Mike Shumack

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Re: Airing up problem
« Reply #1 on: April 07, 2018, 01:33:08 PM »
Mine did that the other day too. It was my rear pass airbags that did not inflating fully and that side of the coach was noticeably low. Now it is working properly again.

Are you having the problem with just the rear bags on drivers side - and not both front and rear drivers-side air bags at the same time? Because the front and rear use different HWH vales.
If just the rear bags are the problem I would suspect the HWH Travel solenoid at the rear six-pack is the cause.

Note how the air for leveling has to go through the Travel Solenoid to get from Leveling Valve (Height Control Valve or HCV) to Air Bags. If the travel solenoid was sticking closed it would limit/slow the air getting to bags.

Ignore the yellow highlight in the attachment - that picture was for another post.
« Last Edit: April 07, 2018, 01:40:02 PM by Mike Shumack »
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Fred Cook

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Re: Airing up problem
« Reply #2 on: April 07, 2018, 02:26:57 PM »
Mike... the problem appears to be the whole drivers side but mostly up front. Is this something that can be readily fixed or is it a huge burden? Thanks
Fred & Cindy
2002 Beaver Patriot Thunder 455, C12 CAT
Towing 2019 Chevy Equinox, AWD Diesel
South Central Missouri, US Army Retired

Pat Long

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Re: Airing up problem
« Reply #3 on: April 07, 2018, 03:09:02 PM »
Does the problem occur when you are driving or when you are leveling.   If leveling then it would be the HWH 6 pack, if while driving I would believe it would be the air ride Travel leveling valves.   My coach has 4, left and right for each axle front and driver, tag works different by set pressure. 

Lee Welbanks

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Re: Airing up problem
« Reply #4 on: April 07, 2018, 03:24:46 PM »
Sounds like the solenoid valves for the front drivers side are not opening all the way or are plugged up, could be only one is operating if you have two valve to the front air bags. Can be a real pain to figure out what is the problem, one way would be to put a test gauge in the line to the front bags and see what you get.

Samuel Sperbeck

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Re: Airing up problem
« Reply #5 on: April 07, 2018, 03:55:21 PM »
Our 2001 PT did the same thing when we first got it. When we got home from Arizona and I could get the coach over my pit I found a loose clamp on the rear drivers side height control valve linkage. I loosened the clamp more and operated the lever on height control valve until the distance between the airbag mounts was at 10". Then I retightened the clamp and that solved the problem. Our PT has the SMC hydraulic leveling between the body and the frame and doesn't have an HWH air leveling system. I know Fred has the same SMC hydraulic leveling as we do from reading about having his hydraulic cylinders repaired. He may not have an HWH air leveling system either.

Good luck Fred on finding the problem. Sam

Gerald Farris

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Re: Airing up problem
« Reply #6 on: April 07, 2018, 04:40:10 PM »
Fred,
You need to thoroughly diagnose your suspension before you start throwing parts at it, but your problem sounds like an adjustment issue or a defective ride height sensor at the left rear.

Gerald

Fred Cook

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Re: Airing up problem
« Reply #7 on: April 07, 2018, 06:38:52 PM »
Fred,
You need to thoroughly diagnose your suspension before you start throwing parts at it, but your problem sounds like an adjustment issue or a defective ride height sensor at the left rear.

Gerald

Gerald, would a defective ride height sensor at the left rear effect the ride height on the left front... which is where the lopsidedness is most noticeable?
Fred & Cindy
2002 Beaver Patriot Thunder 455, C12 CAT
Towing 2019 Chevy Equinox, AWD Diesel
South Central Missouri, US Army Retired

Gerald Farris

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Re: Airing up problem
« Reply #8 on: April 07, 2018, 09:33:14 PM »
Fred,
Your coach only has 3 ride height sensors. One in the center of the front axle and one at each rear wheel. The front sensor controls the ride height of the center of the front axle, but the rear sensors control the ride height of each rear wheel. Since the coach is a rigid rectangle (hopefully), if you raise one rear, the opposite front corner will go down even though the height at the center of the axle will remain about the same. So any difference in ride height from side to side is controlled by the rear height sensors, and any difference in front to rear is controlled by a combination of all three sensors.

Gerald   
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Fred Cook

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Re: Airing up problem
« Reply #9 on: April 08, 2018, 02:07:06 AM »
Fred,
Your coach only has 3 ride height sensors. One in the center of the front axle and one at each rear wheel. The front sensor controls the ride height of the center of the front axle, but the rear sensors control the ride height of each rear wheel. Since the coach is a rigid rectangle (hopefully), if you raise one rear, the opposite front corner will go down even though the height at the center of the axle will remain about the same. So any difference in ride height from side to side is controlled by the rear height sensors, and any difference in front to rear is controlled by a combination of all three sensors.

Gerald   

Ok.... I  understand what you are saying. I now need to get under the coach and find that left rear sensor. It is difficult getting under there because there is not much room to crawl around to do any work. It would be really nice if I had a pit because I really don’t like being under there with only the tires supporting the coach.  With the airbags empty it is nearly impossible to crawl under the couch. Should I be doing this work on the sensor with the airbags full or empty?
Fred & Cindy
2002 Beaver Patriot Thunder 455, C12 CAT
Towing 2019 Chevy Equinox, AWD Diesel
South Central Missouri, US Army Retired

Joel Ashley

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Re: Airing up problem
« Reply #10 on: April 08, 2018, 03:36:26 AM »
Fred, don’t get under there at all without some secure support like heavy blocks or adequate jack stands, especially when messing with the ride height valve mechanics.  In the back you’ll need something capable of holding up at least 8 tons per side... the more the better. 

Some things aren’t worth messing with if you aren’t familiar with it, and this is one I’d personally only try to fix in an emergency “roadside” situation, which is why I carry multiple heavy stands and a 12ton bottle jack.  I’d much rather take it to a shop where such a repair is likely (as in the past at BCS anyway) not particularly expensive, and therefore not worth my own risk.

Joel
« Last Edit: April 08, 2018, 06:09:58 AM by Joel Ashley »
Joel and Lee Rae Ashley
Clackamas, Oregon
36.9 ft. 2006 Monterey Ventura IV, aka"Monty Rae"
C9 400HP Cat
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Gerald Farris

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Re: Airing up problem
« Reply #11 on: April 08, 2018, 04:24:34 AM »
Fred,
Joel is right about the safety aspect of working on a ride height sensor without the proper safety equipment. One move the wrong direction without the proper equipment and the coach will drop to its lowest position crushing anything taller than about 12 inches high. This is not something that you should go into blind. So, if you are going to work on it, you need to do some serious technical reading about air suspensions, and get some safety stands that will support the coach if it starts dropping. The stands can be as simple as heavy wooden blocks if they will support the coach.

Gerald 
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Fred Cook

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Re: Airing up problem
« Reply #12 on: April 08, 2018, 01:05:59 PM »
Joel, Gerald... I agree with your assessment. I am going to take a look and maybe the obvious will pop out. If not then I will take it somewhere to get it fixed.
Fred & Cindy
2002 Beaver Patriot Thunder 455, C12 CAT
Towing 2019 Chevy Equinox, AWD Diesel
South Central Missouri, US Army Retired

Fred Cook

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Re: Airing up problem
« Reply #13 on: April 09, 2018, 10:25:24 PM »
Looked under the coach this morning... no way to access the ride height leveling rod. So... I called around and found a diesel repair place about 30 miles away that let me use their pit for $35 an hour.  Got easy access to the rear left ride height leveling rod and made the adjustment.  Now.... no more lopsided coach. Also.... sprayed all fittings with soapy water and found the rear right, ride height control valve leaking very slighting at two fittings. Owner of the shop said its not a big deal... hope he is right about that.
Fred & Cindy
2002 Beaver Patriot Thunder 455, C12 CAT
Towing 2019 Chevy Equinox, AWD Diesel
South Central Missouri, US Army Retired

Joel Ashley

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Re: Airing up problem
« Reply #14 on: April 10, 2018, 12:23:50 AM »
Certainly happy to hear the issue is fixed, Fred.  As to the remaining fitting leaks, others here have replaced their factory ones with an improved version.  I’ve thought that the next time I’m at Henderson’s or somewhere I might ask them to retrofit as many as is financially practical.  Not having seen the complete underside personally very often and searched out fittings hundreds of times like they have, I’m not sure I could find them all and do it easily myself, crawling around on the ground. 

As I recall the originals are plastic and leak-prone, whereas the better choice is a ferrule and sleeve and insert fitting something like was recently herein described for fuel lines.  Others here can correct my memory on that, and perhaps provide references or links to the replacement they used. 

Leakdowns seem common to every coach and even the slowest ones are a confoundment, especially to new owners that see it as a bigger issue than it usually turns out to be.  But even long-timers consider slowleak-patching a worthwhile endeavor if not too time-consuming, or if one knows precisely where a leak emanates.  Having faith that one can park in a particular aired up position and return much later to find it still the same, with no windshield-threatening twist and without undo wear and tear on the auxiliary pump, is a commendable goal.

I learned the hard way to store on relatively flat ground, flat in at least one direction anyway, and dump the bags almost all the way down.

Joel
Joel and Lee Rae Ashley
Clackamas, Oregon
36.9 ft. 2006 Monterey Ventura IV, aka"Monty Rae"
C9 400HP Cat