BAC Forum

General Boards => Technical Support => Topic started by: Bill Johnson on February 18, 2012, 10:59:21 PM

Title: Air Bag Failure
Post by: Bill Johnson on February 18, 2012, 10:59:21 PM
Yesterday the front air bags deflated while driving.  There is no loss of air pressure and the rear air bags are fully inflated.  Question, is there a relay or something else I should look for to correct the problem?  Again, only the front air bags are de-flated and the air pressure continues to be at full pressure.
o2 Patriot/Cummins
Thanks,
Bill
Title: Re: Air Bag Failure
Post by: Gerald Farris on February 19, 2012, 03:17:02 AM
Bill,
The first thing to look at is the linkage between the front suspension ride height sensor and the front axel. This linkage is a common failure point.

If your coach has air leveling, and it will level on air without a problem, your suspension is OK. The problem is most likely in the front ride height sensor or its linkage. There is also a possibility of a stuck air control solenoid, however not likely.

Gerald
Title: Re: Air Bag Failure
Post by: Bill Johnson on February 19, 2012, 03:46:11 AM
Gerald, Thanks for the advice.  We will look there first thing tomorrow and will let you know what we find.
When trying to track down the pneumatics on our rig (of course no such schematic was provided with the coach) we discovered that the air brake manifold (Norgren) is in the left front electric bay (by trial and error, when we bled it of air, the air brake pressure went to zero).  Sure wish there was a schematic for all of this!
Thanks again, and will let you know how it goes.
Bill
Title: Re: Air Bag Failure
Post by: Bill Johnson on February 19, 2012, 03:48:33 AM
Gerald:  addendum to previous note.  We do not have air levelers.  We have the SMC chassis to axle hydraulic leveling jacks.
Title: Re: Air Bag Failure
Post by: Bill Sprague on February 19, 2012, 01:18:26 PM
If you crawl under, be careful.  Standard advice that has to be mentioned is to be sure there are stout wood block or jack stands in place so that the coach does not drop further while you are under there.

When you do get under it, you will be amazed at how one cheap, tiny clamp and screw holds on to a skinny vertical rod.  That is all that controls your airbags!   It is typically behind the front axle in the middle of the coach.  You might be able to see it from the wheel well with a flashlight.  The vertical rod is about 18" long and about a 1/4 or 5/16 inch in diameter.  If it is bent, you found your problem.  If the clamp has slid on the rod, you should see some rust or dirt showing where it used to be.  

Good luck.

Bill
Title: Re: Air Bag Failure
Post by: Bill Johnson on February 19, 2012, 06:14:53 PM
Gerald/Bill,
That, indeed, was the problem.  One of the rubber "grommets" was broken.  Now to find a replacement for the little darling.
Thanks again,
bill
Title: Re: Air Bag Failure
Post by: Joel Ashley on February 20, 2012, 12:00:52 AM
Bill, how about attaching a tag or two to your thread for future reference.  

Thanks,
Joel
Title: Re: Air Bag Failure
Post by: Bill Johnson on February 20, 2012, 01:02:15 AM
Joel, would be glad to.  Please let me know how to do that and I can also attach a photo of the part (tried attaching one to an earlier post but it failed to post).
Bill
Title: Re: Air Bag Failure
Post by: Jim Nichols on February 20, 2012, 04:14:25 AM
Beaver Coach Sales ( new name escapes me ) in Oregon should have them in stock. Before replacing it check the up and down travel. The arm it is attached to may be to close to brackets. I had to bend the flat arm the rod was attached to 1/4" away from the frame bracket.
Title: Re: Air Bag Failure
Post by: LarryNCarolynShirk on February 20, 2012, 06:14:46 AM
Your wish is my command.  Threads attached.

As a temporary fix, could you use a piece of 1/4 rubber tubing?

Larry
Title: Re: Air Bag Failure
Post by: Jerry and Kay Hudson on February 20, 2012, 09:18:07 AM
Any large truck stop with a repair shop should also have the rubber piece in stock. Some will sell you just the rubber piece but some will try and sell you the whole kit.  I learned the hard way. I had a roadside repair done outside of Houston. After I found out how simple it was to repair, i now carry a couple of the rubber pieces as spares.

Jerry
Title: Re: Air Bag Failure
Post by: Joel Ashley on February 20, 2012, 12:15:53 PM
Bill, I see that Larry, as Moderator, apparently added tags to your forum thread for you (see bottom of this page).  But for future original thread posts, you should find near the bottom a field for adding tags so we can easily find your topic again if the subject comes up in the future.  Only those that start new threads and administrators/moderators can add tags.  The tags you add end up as part of the Tag Cloud at the bottom of the Search page.

You can also go back and add tags to any old thread you started, by selecting the Modify button on it, and Full Edit, so the Thread Tags field will appear for you.

Joel
Title: Re: Air Bag Failure
Post by: Bill Sprague on February 20, 2012, 01:40:33 PM
Quote from: LarryNCarolynShirk
Your wish is my command.  Threads attached.....
Can you add "leveling valve"

Title: Re: Air Bag Failure
Post by: Gerald Farris on February 20, 2012, 03:05:53 PM
"Leveling valve" added to Tags.

Gerald
Title: Re: Air Bag Failure
Post by: Bill Johnson on March 02, 2012, 07:28:58 PM
I wanted to provide an update to the leveling valve issue.  The part (Haldex Linkage Repair Kit #RN10JC) is available via NAPA.  Our local stores did not have it in stock, but could easily obtain it.
The actual repair/replacement is relatively simple and since I was replacing one, I changed all three (1 front and two rear).  I have attached a picture of the item.
I should note that this was relatively simple, especially if you have a son who is much younger and more limber than most of us!
Title: Re: Air Bag Failure
Post by: LarryNCarolynShirk on March 03, 2012, 01:04:11 AM
Bill,

Would you please copy your last post the the Sources for Suppliers and Parts ...  Board, and add Air Bag Valve to the thread.  It is good information to have on that board.

Thank you,

Larry