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Is some hissing normal?

February 19, 2017, 05:49:17 pm

There is a little air leaking from a device at the front middle section of the rig, in front of the front tires, mid-section. Please take a look at the photo and let me know what this device is and why it would be hissing with the engine running. Only a little air was coming out, but it loud was enough to be heard from around the front of the rig. Thanks.

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Re: Is some hissing normal?

Reply #1 – February 19, 2017, 05:51:02 pm

Tim, that's your ride height valve, and air should only be coming out when it's dumping air.

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Re: Is some hissing normal?

Reply #2 – February 19, 2017, 06:22:27 pm

May have slipped out of adjustment, so the lever is not "centered".  In the neutral position (at ride height) should be no air venting.  Raise the lever a little, or lower it a little, air is exhausted to adjust the suspension height.

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Re: Is some hissing normal?

Reply #3 – February 19, 2017, 06:25:39 pm

Correct,

The ride height valve is a basic three position valve.

It can let air through it to the air bag(s) if ride height too low.
It does nothing (no air in or out) at ride height.
And, if ride height too high, it will exhaust air.

So, if it continues to leak air once ride height is achieved, replace it.

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Re: Is some hissing normal?

Reply #4 – February 19, 2017, 06:31:25 pm

Is this leak while in Travel or Level Mode?

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Re: Is some hissing normal?

Reply #5 – February 19, 2017, 09:03:04 pm

The hissing ride height valve is missing the bottom exhaust port weather protector boot.  Dirt and water can enter.  Many have made their own with a hose, filter material, etc.

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Re: Is some hissing normal?

Reply #6 – February 19, 2017, 09:13:03 pm

The HWH height was in the "Raise" mode, so I could crawl under the rig (with safety blocks of course).  I think it hisses at ride height, so attention is required.

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Re: Is some hissing normal?

Reply #7 – February 19, 2017, 09:14:15 pm

I found on my coach, with the bags inflated all the way the ride height valve is  trying to let air out of the bags.

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Re: Is some hissing normal?

Reply #8 – February 19, 2017, 09:36:06 pm

Tim,
If you hear air venting out of the ride height control valve when in level or raise    (No green travel light) then it is either a travel solenoid or the ride height control valve. I would disconnect the two air lines that come down to the ride height control
valve from the HWH manifold ( they should T together at the control valve ) and submerge them in soap water to see if any air is leaking through the closed travel solenoids.
And your coach will go out of level if a travel solenoid is leaking . Any bubbles, you have a travel solenoid leaking. No bubbles, then probably a bad ride height control valve. 
Find out which one before you buy any parts.

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Re: Is some hissing normal?

Reply #9 – February 20, 2017, 01:06:06 am

Maybe I am not understanding what you are saying, but when you raise the whole coach and then just let go of the button, the normal function of all the ride height valves is to dump the air until it reaches ride height. However, if you have raised the coach and then hit the button on the top left of the HWH control panel (turn the level system back on), it will keep the coach at that height until you turn the level system off,  release the parking brake, or put it in gear (while the engine is running of course). To raise the coach to the max for frame blocking; I let the pressure build almost until cut off, hit the raise button, and when the air pressure gauge will hold at about 100 to 105 PSI while the raise button is held down, I know that the coach is raised high enough to set the frame blocks. Then I shut down the engine, hit the level button to hold it in the raised position and place the frame blocks. At this point, you should not hear any air escaping.
Don

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Re: Is some hissing normal?

Reply #10 – February 21, 2017, 07:02:28 am

Thanks for the info. I kept holding the Raise button, but after letting go, there was loud hissing from somewhere under the rig. I will try shutting down the engine and pressing the level button in order to maintain clearance for the frame blocks.

BTW: After the engine shuts down, the front ride-adjust valve stops hissing.

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Re: Is some hissing normal?

Reply #11 – February 21, 2017, 08:47:53 am

Tim I sent you a PM.

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