Trailer brakes lockout device

[Steve Roquemore]

Been having lots of issues with a trailer we bought last year. One of those is there is not a way to mechanically lock out the brakes when backing up when the electrical override from the backup light fails. Here is my $6 solution.

 

[Belzelbub]

I had the same coupler on my trailer up until a couple years ago. Not having a mechanical lockout was an issue on a couple occasions. When my mechanic tried to move the trailer with a forklift, it didn’t work very well. Only had an issue with my truck on a couple occasions.

First time it happened, I pulled off the 5 pin connector and replaced with a 7 pin. That eliminated the adapter. When it happened again, I noticed corrosion inside the 7 pin. So, I got a new one, and this time, after making the connections, I filled the back side of the 7 pin with dielectric grease. No issues after that.

I’ve since swapped that coupler for a non-surge coupler since I switched to a Hydrastar EOH unit that works with my trailer brake controller. Huge improvement in ride.

 

[Tracy]

I drill a hole in the side of the slider directly in front of the collar. Pull your coupler lock pin, stick it in that hole and back up. One 3/8 drill bit and 5 minutes time.

 

[Tracy]

 

[NW Dive Dawg]

Nice mod Tracy! I will steal that idea! I have surge brakes and although I maintain and rinse them well, my contingency plan to date is to keep a good set of vice grips and a wheel chock in the truck. If I have a lock-up situation when backing and the actuator isn't working for any reason., I can just chalk a tire, then pull forward to disengage the lock-out, and then clamp on the vice-grips to maintain the lockout... (see pic below with red arrow) Only other thing I will mention is that maintaining your 7 pin connector with dialectic or white lithium grease and rinsing your trailer brakes religiously with HOT fresh water is a good thing... If you already have your water heater in the garage, then it's fairly simple to run a line and install an exterior mix valve. Having HOT fresh water mix valve is awesome for boats, dive gear, dogs, trucks, etc.....

Cheers....

 

[rhwestfall]

My trailer hitch assembly came with the pin to lock out the brakes when power is not provided ..

 

[broncobowsher]

I've only had issues with disk brakes. Proper trailer drum brakes are single bore wheel cylinders and are self energizing when applied going forward (normal drum brake design). But braking going backwards they are de-energizing.

Self energizing brakes use the wheel cylinder pressure to apply pressure to the leading (primary) brake shoe. The drag from the primary brake shoe is transfered into the trailing (secondary brake shoe) and that does the majority of the braking. So much so that the secondary shoe has more brake material on it so they should wear about evenly. Normal car drum brakes are double piston wheel cylinders that will brake in reverse nearly as well as going forward. Trailer being single piston wheel cylinders will want to pull the trailing brake shoe away from the drum (instead of pushing into it) This allows backing with only some drag on the brakes instead of full brake apply.

Disk brakes don't care about rotation direction. I welded 2 large bolts to my hitch and have a wedge I drop in. Nice part is not having to find a way to stretch the coupler to get a pinning bolt in. Drop in the wedge and if it won't back, a little tug forward will stretch the coupler, the wedge drops in deeper and stays there as you back up all you want. When done give the wedge a little wiggle and it pulls right out. Won't jam like a pin will.