Community Forums

MikeandJan · 12-05-2018, 08:15 PM

We store our motorhome at a very nice campground in Mebane, NC, when it's not in use. Last week I went over to get some tools I had left in the basement and was surprised there had been an accident just before my arrival in the storage lot. A Winnebago DP (about 40' and probably about 2010) was backing into a parking space and, when he pulled forward to straighten out, kept going, crossed the gravel road and hit the hitch end of a fifth wheel (about 35' long). The impact pushed the 5th wheel about 50 feet despite the leveling jacks being down. The windshield area and front cap of the DP were destroyed. The forward portion of the fiver was high enough that it looks like the entire frame around the Winnebago windshield is bent. The fifth wheel has fiberglass damage and probably some stabilizers bent.
Second hand account is that the driver said he experienced a complete brake failure. I don't intend to criticize the driver but I sat and reminded myself that if it ever happens to me, I will try to remember to turn the key off and pull the parking brake control, which I think I can do almost simultaneously. The driver said that he stopped the Winnie by shifting to reverse and then backed up about 20' to separate the two rigs - that's how they were parked when I saw them.
Trying to analyze how an air brake failure could occur, I think it would have to be a mechanical linkage failure in the pedal system, but I'm not a mechanic. I am not familiar with the pedals in that coach, but it could also be momentary confusion between the brake and accelerator. Anybody have an opinion how this kind of mechanical failure could happen? Best course of action if it does happen?

WILDEBILL308 · 12-05-2018, 08:37 PM

"when he pulled forward to straighten out, kept going, crossed the gravel road and hit the hitch end of a fifth wheel (about 35' long). The impact pushed the 5th wheel about 50 feet despite the leveling jacks being down."
It sounds like he hit the gas pedal and didn't let up. How else would he be going that fast just pulling forward to straighten out?
Further food for thought. How could he move it without air? The emergency brake will not release without air preshure.
Bill

Kraken · 12-05-2018, 08:51 PM

Well, I would give the man the benefit of the doubt, and go with failed brakes until proven otherwise. If it's not a brake failure, then could be a medical issue; perhaps a new one not previously experienced. When taken by surprise, people can get flustered by what to do next, and sometimes do the wrong thing.

Mr_D · 12-05-2018, 08:59 PM

No way could it be a brake failure on a full air system. Lose air and the rear brakes lock up. Air pressure gets down 60 psi the rear brakes come on and you WILL stop.

SlowJoe · 12-05-2018, 09:21 PM

Aside from all of the questions and improbability surrounding the "brake failure" I would suggest that there is no way that he could have pushed that trailer 50 feet with an idling engine. He had to be giving it fuel....

I would imagine he hit the throttle instead of the brake some how and panicked.

RoadDogYVR · 12-05-2018, 09:30 PM

Only thing I can think of (and it would be seriously farfetched) is if there was an airline leak at the treadle valve or on the manifold on the firewall which would cause brake application air to vent to atmosphere instead of applying the brakes. This could continue to vent for some time before the air tank reservoirs would be depleted enough to trip the low pressure and engage the spring brakes, assuming this is a drum brake system.

OR... if the slack adjusters on the brake actuators were MASSIVELY out of adjustment, the application brake air pressure wouldn't allow the s-cam to rotate far enough to engage the friction surface. If the coach had recently been flat- or front-lift towed it is POSSIBLE that the slacks were loosened or disconnected altogether by the tow operator. In that case, even applying the Park brakes by evacuating the system air from the brake chambers would not actuate the spring brakes effectively as again the s-cam couldn't rotate enough to bring the friction surface into contact with the drum.

Sounds more like mistaking the throttle for the brake or getting a foot stuck or a medical incident than brake failure, which would be easily verified onsite if investigated.

saddlesore · 12-05-2018, 09:42 PM

The only thing I can come up with is.... I HAVE had a treadle valve (brake pedal valve) shear a pin or have had the pin work out of place and I have had a plunger in the treadle valve freeze up (due to contaminates) ..All of which resulted in no matter how hard you push it....nothing happens.. but all of these were on rigs with well over a million miles on them...

FIRE UP · 12-05-2018, 09:45 PM

Well,
I too don't like to lay blame without knowing ALL the facts, (remember Jack Webb, "Just the facts mam"). But, based on the OPs description of what supposedly took place, I too am gonna side with the "hit the accelerator" clan. To be just straightening out, IN A PARKING LOT, AND IDLING AT THAT, to be able to push a 5th wheel trailer, that, according to the OP, had the JACKS DOWN, 50 feet, takes a ton of energy. In all my RVing career, and time on the FD with air braked fire trucks, I personally have NEVER read of any air brakes failing upon application. Does this mean it can't happen, nope, not at all. It just means I've not ever heard or read of it.

How many times have many, many of us seen on the 5:00 news, "vehicle crashes into store or, vehicle crashes into home"?? About 99.9999% of the time, it was because the ACCELERATOR was either mistaken for the brake pedal or, there was physical problems with the operator, i.e. heart attack, stroke, intoxicated etc. Anyway, yeah, the "complete brake failure" theory sure seems pretty sketchy to me.
Scott

**TonyDi** · 12-05-2018, 09:51 PM

I have heard people complain about applying the brakes and simultaneously pushing down on the throttle by mistake. Their foot was on both pedals and didn't realize it. Bam!

Domo · 12-05-2018, 10:49 PM

Quote:

Originally Posted by Mr_D

No way could it be a brake failure on a full air system. Lose air and the rear brakes lock up. Air pressure gets down 60 psi the rear brakes come on and you WILL stop.

Exactly correct.

guardrail53 · 12-06-2018, 12:24 AM

In 35+ years driving air brake trucks, only once did I have a treadle valve fail, it froze hard as a rock, and when I went to stop, Wow, what a shocker! Quick downshifts, Jake brake, and the trailer brake handle, and I got slowed down, pulled into a TS, pulled the parking brake knob, and went inside, bought some air brake de-icer! Took the main braided line off the compressor, filled it with the de-icer, put it back on, turned the floor heat up, and got the treadle valve freed up, and drove on! It was -20 that night! I found out later that the heater element in the air dryer has failed, and the moisture in the system had froze!
I am in the camp that this was drive error!

JMHO! Rail!

sdennislee · 12-06-2018, 01:55 AM

If he pushed a 5th wheel 50’ I also vote for mistakes the throttle for the brake. At idle he would have dented both but doubt he would have moved the 5th wheel more than a few inches.

twinboat · 12-06-2018, 04:39 AM

Back when trucks had hand valves for the brakes on the steering column, we had a driver leave his 10 wheel dump truck with it holding on a hill.

It rolled 30 feet into another parked truck. It cracked the hood and bent the grill. That's it!!

I'm with the pedal confusion group.

CountryB · 12-06-2018, 06:58 AM

I'm in FL and it seems every month or so, there is a story in the local news about a senior citizen stepping on the gas pedal instead of the brake and driving their car into the store front. So I would not be surprised if the same thing happened with this RV.