Trailer warning, this could happen to you

[Hay Dude]

I have your typical Pequea 10,000lb 20’ trailer. It’s a 2022, so still fairly new. Been a very good trailer.
Typical uses are hauling mowers and lighter equipment around, nothing unusual.

One time last year, while running empty down the highway, I hit a huge bump. Trailer actually “got air”, landed and the trailer brakes locked. By the time I quickly got pulled over, I lost 2 of the 4 tires. Came very close to a loss of control of the trailer. I never understood why the brakes locked. Trailer worked perfectly since that event. I replaced the 2 bad tires, trailer break-away kit and the battery and the battery housing, just in case it had some kind of glitch in it.

Fast forward to 2 weeks ago and the same thing happened, but at very low speed, so just a couple skid marks.
Then last week, it happened again on my driveway, again at low speed, but I knew I needed to figure this out before a tragedy. Looked at everything I could think of.

While disconnecting the trailer, I pulled the 7 pin plug and heard a rattle in the plug itself. I removed the tiny locking screw and slid the cover back on the plug. Inside the cover, one of the short brass wire anchoring screws (the one for the center lug) had come loose and was floating around.

I believe that randomly, that wire anchoring screw would jump into the right spot where the brake connection wire is and ground out with the terminal next to it and cause the brakes to lock. Could this have been the reason the brakes locked? Makes sense to me.

I thought to myself that anyone with a trailer plug could have this happen. Pull the cover off your plug. Tighten the small screws. Make sure you remove or greatly tighten/use thread lock on any that are unused!

 

[dodge man]

Good catch and a tough one to find.

 

[Topzide]

I've got a wire in all 7 locations on mine. Hopefully, that'll keep them locked in place, but I will check them when I do my annual on it. Good catch and sure that would cause that issue. Never thought how nice it is to have reverse lights on the car trailer!

 

[JPRambo]

I thought you were going to tell the same story I had once. Towing my empty 14' duel axle and hit a bump and the leaf springs on the front axle flipped. Causing the tail to wag the dog. Exciting at 50 mph.

 

[Fixastuff]

I fill them with silicone when I put them back together.

 

[nyone]

That's a good catch. Now why did only 2 of the 4 brakes lock up?

 

[M59]

I have your typical Pequea 10,000lb 20’ trailer. It’s a 2022, so still fairly new.

One time last year, while running empty down the highway, I hit a huge bump. Trailer actually “got air”, landed and the trailer brakes locked. By the time I quickly got pulled over, I lost 2 of the 4 tires. Came very close to a loss of control of the trailer. I never understood why the brakes locked. Trailer worked perfectly since that event. I replaced the 2 bad tires, trailer break-away kit and the battery and the battery housing, just in case it had some kind of glitch in it.

I believe that randomly, that wire anchoring screw would jump into the right spot where the brake connection wire is and ground out with the terminal next to it and cause the brakes to lock. Could this have been the reason the brakes locked? Makes sense to me.

I thought to myself that anyone with a trailer plug could have this happen. Pull the cover off your plug. Tighten the small screws. Make sure you remove or greatly tighten/use thread lock on any that are unused!

Thanks for the heads up. Another reason I am part of this forum.

That's the kind of exciting day no one ever wants. Good to hear you ran it to ground. (pun intended )

 

[LouNY]

I fill them with silicone when I put them back together.

Many "silicone's" will cause corrosion, they have an acetic acid base that citrus smell that you smell while working with it. A latex caulk will not cause corrosion

 

[Fixastuff]

Many "silicone's" will cause corrosion, they have an acetic acid base that citrus smell that you smell while working with it. A latex caulk will not cause corrosion

Thanks! I’m not sure what caulk I used last time actually but I’ll make sure it’s latex next time.

 

[gengine]

I have had the whole center pin come out, not just the screw and do the dame thing. I was going to respond with that, but you already had it solved. Thanks for posting!

 

[Hay Dude]

Seems like a bad accident waiting to happen

 

[TMGT]

I switched all my trailers over to junction boxes with a one piece molded connector. Way less problems compared to the replaceable end 7pin connectors.

 

[D&D]

I switched all my trailers over to junction boxes with a one piece molded connector. Way less problems compared to the replaceable end 7pin connectors.

Or a female plug on truck and trailer and a removable cord in between ?

 

[Topzide]

^^^^^
That helps with theft also! Allows you to wire the power wire to the brakes!

 

[flyerdan]

Sounds like a piece of heat shrink tube on the brake pin would be good insurance, if it would allow the case to close, some of them have pretty tight tolerances.

 

[skiff]

That's a good catch. Now why did only 2 of the 4 brakes lock up?

Only one axle of tandem axle trailers have brakes (at least that is the case on my 5th wheel and car trailer).

 

[RandyT]

Only one axle of tandem axle trailers have brakes (at least that is the case on my 5th wheel and car trailer).

Were supposed to have brakes on all axles above 5000 pounds or 2268 kg. A lot of tandem axle trailers being towed around here with brakes on one axle or in the case of cheap trailers no brakes at all.

 

[Hay Dude]

I have brakes on both axles.
One set locked up more than the other and caused the tires to grenade.

IMO, the trailer plug/cord should be molded and sealed from the factory to prevent moisture infiltration, incorrect wiring and loose connections or floating brass screws.

If it’s damaged, the entire cord with molded & sealed plug should be replaced. That cord should be wired into the breakaway box, where wires are spread out and less likely to be mis wired.

 

[mrmikey]

Somewhat similar story years ago on the news. There was a deadly accident at an intersection. A fella hauling a trailer with a small loader (I think) went thru the stop sign he had and T boned a car that had the right of way. They couldn't figure out why as the guy was familiar with the area. At the scene there was a series of regular intermittent skid marks on the asphalt well before the intersection and they couldn't figure out why would he pump the brakes.
Ended up he was intending to turn at the intersection so obviously he had his turn signal on. Previous day he had rewired the trailer plug and inadvertently wired the trailer brakes to the turn signal. A very simple mistake.

 

[dkmc]

Somewhat similar story years ago on the news. There was a deadly accident at an intersection. A fella hauling a trailer with a small loader (I think) went thru the stop sign he had and T boned a car that had the right of way. They couldn't figure out why as the guy was familiar with the area. At the scene there was a series of regular intermittent skid marks on the asphalt well before the intersection and they couldn't figure out why would he pump the brakes.
Ended up he was intending to turn at the intersection so obviously he had his turn signal on. Previous day he had rewired the trailer plug and inadvertently wired the trailer brakes to the turn signal. A very simple mistake.

Wow that's quite a reminder to 'check your work'!