Tow Bar Failure

[dave&ginny]

Originally Posted by Gary.Jones

Dave

Several people above have asked you for some very important information and I am looking forward to your response. The most important is the issue of did your safety cables break. It appears that they did not and the truck remained behind you and rammed into the coach. If that is correct, then the AFO did exactly what it was supposed to do. The AFO only activates the toad car brakes if the toad separates from the coach completely.

Now, i know the Blue Ox seems to be a very popular tow bar.... I see lots of owners using those tow bars on their rigs. However, I have always looked at BlueOx tow bars very carefully and felt that they simply were not engineered strongly enough. Further, the fact that BlueOx advocates that their tow bars be examined EVERY YEAR to look for weaknesses and failures tells me something important. I have a buddy with a Blue Ox tow bar and he takes it to be looked over by Blue Ox at a major RV rally every year and he frequently has the factory engineer inspectors often have suggestions on what needs to be replaced. I've never been impressed and have never owned one.

Now, really looking forward to some additional clarification of what happened and what failed and the model hitch you were using.

And glad that you and everyone else was not hurt. Nice job of bringing it all to a safe halt.

Gary

Gary,

the tow bar I used was the 10,000l lb Avail. I just checked that bar carefully looking for cracks in the area where it broke because someone had posted a problem last November or December either on FB or this forum. This was our first trip since that post. I could not see any signs of cracking and the metal is clean and shinny where it did break, leading me to believe that this wasn't a on going issue.

As for the Air Force 1, once the air line was pulled free from the truck, there weren't any brakes. Yes the safety cord was pulled.

On our way to the AIM rally, my wife and I discussed problems that others have had with these tow bars and we agreed that since it was over 5 years old that we should look into replacing it out of caution. Little did we know that a we wouldn't complete this trip with it.

The saving grace was that the safety cables held but they're very stretched at this point.

[Kid Gloves]

Originally Posted by dave&ginny

The safety cable was pulled but once it broke and the air line was severed the brakes didn't work on the truck. There's no stored air on the truck for activating the brakes once the air line is gone.

There is a reserve air supply that is part of the operating unit that activates the toad brakes in the event of a breakaway. It is necessary each time the toad is connected to press the brake pedal in the coach for at least 3 seconds after the tanks in the coach are at full pressure in order to fill the reserve air supply.

[dave&ginny]

Originally Posted by Turbojack

Could you please take a picture further away so I can figure out what broke I looked at mine and can not figure out what part broke

My phone is dead right now and it has the pictures on it, but I will post a picture tomorrow or you can private message your email and I'll send you one. Basically it's before the 2 connecting arms at the hinge area.

[dave&ginny]

Originally Posted by AZ RV'r

I think this thread should be re-named because that AF1 everyone with a diesel brags about should be under the same amount of fire as that Blue Ox tow bar in my opinion, they both failed miserably. One of the failures is equally as dangerous as the other.

Maybe think of starting a parallel thread called Air Force 1 complete and total failure.

If anything we should be praising those safety cables.

I would have to agree! I was very disappointed with the air force 1 system. It didn't occur to me that the system wouldn't work without air. There's no real back-up for the loss of air.

In a trailer with electric brakes, once that safety cable is pulled, the breaks stay locked up as long as there's battery power to activate the brakes.

[dave&ginny]

Originally Posted by Kid Gloves

There is a reserve air supply that is part of the operating unit that activates the toad brakes in the event of a breakaway.

I don't know where the reserve would be. The extra air tank is on the motor home not on the toad.

I tested the pull away switch after the original install and it worked fine but I didn't try it with a severed air line.

[Kid Gloves]

Originally Posted by dave&ginny

I would have to agree! I was very disappointed with the air force 1 system. It didn't occur to me that the system wouldn't work without air. There's no real back-up for the loss of air.

In a trailer with electric brakes, once that safety cable is pulled, the breaks stay locked up as long as there's battery power to activate the brakes.

In the event of a breakaway, the system does work without air from the coach, if operated properly.

[Kid Gloves]

Originally Posted by dave&ginny

I don't know where the reserve would be. The extra air tank is on the motor home not on the toad.

I tested the pull away switch after the original install and it worked fine but I didn't try it with a severed air line.

Per the instructions, the reserve air supply is in the operating unit.

[Gary.Jones]

Dave

Now I may be completely wrong, and if I am, then I have been wrong a very long time, but the AFO does, to my understanding, not need the air line from coach to toad to stop your car or truck when your toad breaks totally free, and the break-away system pressure is applied to your brake system by the AFO operating unit that is located in your truck....

Let me quote the description from the AFO owners manual.

"... The provided coach installation was designed in cooperation with Mike O’Neil at Spartan Chassis and meets the
operational requirements of Spartan (per Mike O’Neil) and Freightliner (per Tony Sipple). At time of publication, Spartan
and Freightliner are the only chassis with specific guidelines other than FMVSS 121.

In the event of a breakaway, the reserve-air supply (located within the operating unit) is used to apply the towed vehicle’s
brakes. The towed vehicle’s brakes remain applied until the break-away pin is replaced. To be sure that the breakaway
tank is charged, you should apply the coach’s brake pedal completely for 3 seconds after the coach has been allowed
to completely ‘air-up.” ...... bolding and underline added by GEJ

The system does not need the air line from the coach. In fact, it is exactly because it is assumed that the toad has completely broken away from the coach and is not "free". In that situation of it being totally separate from the coach, the tow bar, the air line, and the emergency cables, then the tag line that goes from the coach to the plastic pull out break away pin on t he front of the toad is what activates the AFO to panic stop the toad once it is free of the coach. Now, if that small cable does not pull out the pin because the toad is still connected to the coach and is not completely "free" from the coach, then the AFO will not apply the brakes on the toad. Also, if that break-away line is not attached to the pull out plastic pin, again it will not apply the toad brakes.

Now, if that is not how it works.... I have been completely wrong for 7 to 8 years. Is this not how the AFO works??????????

Gary

[Kid Gloves]

^^^That is my understanding. An ideal set up in the event of a tow bar assembly failure would be the safety cables as the first line of defense. If those failed, the air line would sever and the breakaway switch would deploy in short order, so which one goes first isn’t a major concern. Personally, I’d opt for the breakaway switch last.

In this case, the air line should not have detached and the breakaway switch should not have deployed as long as the safety cables were still intact. This would have allowed the coach to control the toad brakes.

[Gary.Jones]

I have a word wrong that is the opposite of what it should be... In the next to last paragraph of my long post immediately, the second sentence of that paragraph should read.....

....In fact, it is exactly because it is assumed that the toad has completely broken away from the coach and is NOW "free"....."

Sorry

Gary

[tqqest]

I have the AF1 installed on my Jeep Wrangler Rubicon. As I was disconnecting after arriving at camp, I had already disconnected the airline and safety cables. As I was unhooking the breakaway cable, I accidentally pulled out the breakaway pin. I heard a blast of air, and sure enough, the brakes on the Jeep were fully set. I had to put the safety pin back to release the brake pedal.

I am not sure what happened in your case, but the AF1 works as advertised in my vehicle, and is the best of the 3 different systems I have used.

I am really interested in getting more information on what happened in your case!

Regards

[roger8070]

Sorry about your situation, but glad it was not worse. It is not clear from your photos, but was wondering if your Avail tow bar was of the old design? There is a thread on the Newmar forum of this same tow bar failure. https://www.irv2.com/forums/f103/blu...re-511636.html See post number 3. If yours was the redesigned tow bar that is definitely a concern for many.

[jbhobbs54]

I just received my tow bar back from BO after being serviced, it's a good deal and they pay shipping both ways. I too purchased mine in 2015 when we got this coach, my second one from BO. When they called to say it was done they said they replaced the tube that went into the receiver on the coach. I know that I had drug the tow bar when coming off a ferry in Vermont, so maybe I did more damage than I thought. After seeing this I'm glad it was replaced.

[andy29847]

A truck that big on a trailer is not going to be any fun to tow. Not to mention the fun with trailer tires, brake and bearing maintenance, and parking the trailer in a campground.

FWIW, I've had a trailer un-hitch itself and the safety cables worked, just like yours did.