Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: Familyrig on November 06, 2021, 01:38:04 pm

Title: Need assistance / blown airbag
Post by: Familyrig on November 06, 2021, 01:38:04 pm
Lost the rear drivers side airbag behind the tire coming home.  I was able to cap the airline off at the bag and limp home but it does not appear to be adding air to the other bag?  I will need to raise the motorhome to put on stands to replace the bag.  Not sure what I am missing?  Thanks for any and all help.  David.
Title: Re: Need assistance / blown airbag
Post by: Chuck & Jeannie on November 06, 2021, 01:41:18 pm
Did you have pressure in the remaining good air bag at that corner when you were driving home?  Or were both air bags deflated?

Title: Re: Need assistance / blown airbag
Post by: wolfe10 on November 06, 2021, 01:42:08 pm
Trace the line from RIDE HEIGHT VALVE.

And, I would not drive far with a bad bag.
Title: Re: Need assistance / blown airbag
Post by: Familyrig on November 06, 2021, 01:50:54 pm
Did you have pressure in the remaining good air bag at that corner when you were driving home?  Or were both air bags deflated?


The other bag my son saw raise and fill a little.  It lifted the rear corner enough to get about 4" of clearance above the tire.
Title: Re: Need assistance / blown airbag
Post by: Familyrig on November 06, 2021, 01:52:09 pm
Trace the line from RIDE HEIGHT VALVE.

And, I would not drive far with a bad bag.
Will do.  Let me check.  We were about 3 blocks from home.  Kept it at idle the whole way.
Title: Re: Need assistance / blown airbag
Post by: Chuck & Jeannie on November 06, 2021, 01:58:43 pm
The other bag my son saw raise and fill a little.  It lifted the rear corner enough to get about 4" of clearance above the tire.
David,

Is the coach air system pressure at least 120 psi when you are trying to raise the coach?

I have read on this Forum that one (functional) air bag is sufficient to raise a corner of the coach to ride height.  I have never encountered this situation, so I don't know if this is true.

BUT, even if one air bag can keep the corner up high enough to move the coach, it is possible that the same single air bag is not capable of raising the corner high enough to insert your safety stands.  Again, I don't know if this true or not.

You may be able to find a small hydraulic or mechanical jack that could be inserted between the frame members next to the blown bag.  If so, the jack could be used to help lift that corner high enough to insert the safety stands.

Title: Re: Need assistance / blown airbag
Post by: Familyrig on November 06, 2021, 02:09:26 pm
Chuck,

That is always what I have read and was assuming would be the case when I plugged the airline going to the bad bag.  I am getting to 120psi on the system but it still is not lifting that corner.  The weird thing to me is the travel light still coming on with a low corner?  I would think unless the rig is balanced this would not light? 

The hydraulic jack is definitely my next step.  I was thinking the same regarding maybe the one bag cannot lift the corner on its own.  With the jack assisting hopefully this will work. 

Thanks for the help.  I am finally getting some food and will report back in a little while.
Title: Re: Need assistance / blown airbag
Post by: craneman on November 06, 2021, 02:15:04 pm
The travel light only tells you that there is sufficient air pressure in the tank to raise the coach. Nothing to do with actual leveling.
Title: Re: Need assistance / blown airbag
Post by: Chuck & Jeannie on November 06, 2021, 02:18:59 pm
The weird thing to me is the travel light still coming on with a low corner?  I would think unless the rig is balanced this would not light? 
This is a common misconception.  The travel light does not indicate that the coach has achieved correct ride height at all 4 corners.

Below excerpt from the HWH 600 Series Service Manual  https://www.hwhcorp.com/ml11148.pdf

"TRAVEL" light - This light will be on if the leveling system is off and the coach suspension is operable.

Below excerpt from the HWH Leveling System Text Book  https://www.hwhcorp.com/ml20635.pdf

The "TRAVEL" Light. This green indicator light will only work with the ignition on. This light is on whenever the ignition is on if the leveling system panel is off, provided there is sufficient air pressure in the suspension. The "TRAVEL" light only means the leveling system is off and the air system has started to build air pressure. It does not mean the vehicle is at the proper ride height.



Title: Re: Need assistance / blown airbag
Post by: Pierce & Gaylie Stewart on November 06, 2021, 03:15:22 pm
Trying to replace the air bag using the other bag is going to make things hard. You need to get all ducks in a row before starting. It may be possible to use a tubeless repair kit to do a temp repair on the leaking bag. It makes it really easy if the frame is jacked up high so there is a lot of clearance. No need to remove fender in many cases depending on where the hidden nut is. Here is what I made.

Wheel on opposite side should be securely chocked. Don't try to change bag without safety stand of some kind in place on frame and next to jack.

Pierce
Title: Re: Need assistance / blown airbag
Post by: Pierce & Gaylie Stewart on November 06, 2021, 03:18:08 pm
Forgot the last photo. No need to compress bag, just 10 seconds to put into place.

P
Title: Re: Need assistance / blown airbag
Post by: Lon and Cheryl on November 06, 2021, 03:30:16 pm
On my 95 U320 with the Cummins M11, one rear air bag will not have enough lifting force to raise the rear on either side.
Title: Re: Need assistance / blown airbag
Post by: dsd on November 06, 2021, 03:45:02 pm
Can always position a replacement bag next to old bag on rails and air it up separately
Scott
Title: Re: Need assistance / blown airbag
Post by: kb0zke on November 06, 2021, 07:06:42 pm
WE had our air bags replaced a few years ago. Two guys working, one on each side. They were almost racing each other. Took about 10-15 minutes per bag for seven of the eight. The stubborn one took nearly an hour and they ended up cutting it out. Seems there is always one troublemaker in the bunch. Sure hope the one you are replacing isn't that one.

Just a thought: while you are replacing that one, why not replace at least the other one in the pair? Maybe do all eight. I suspect that if the one wasn't destroyed by a road hazard or something like that it may just be the first one to fail.
Title: Re: Need assistance / blown airbag
Post by: Familyrig on November 06, 2021, 10:44:46 pm
Thank you all for the assistance and help.  After spending time tracing out the air hoses to the manifold, taking the hose off the good bag and verifying air pressure, I tried to lift it again and found I wasn't giving it long enough.  Assuming due to one bag lifting the entire corner it just took more time.  I was able to get the motorhome up and on stands.

I have the bad air bag out and pb blast on the other rear 3.  I ended up taking the side panel off which was extremely easy.  It took a little finessing to slowly pry the sides off due to the sealant but no cracks and went pretty smooth.

Once again, thanks all for helping me to sleep better tonight.  It is so cool having such a great forum that is ready to help in the moments that I am the most stressed!

David