Just another opportunity to dismantle the front of the car

RVs are heavy. Ours is rated for a maximum weight of 24,000 pounds and a combined maximum weight — with whatever it’s towing — of 30,000. Getting all that weight moving and then stopping it again is a feat. I like being able to stop, frankly. I find that comforting. To that end, an auxiliary braking system for the Subaru seems like a fabulous idea. Supposedly there’s a law regarding it as well, but aside from any legal requirement it seems like a Good Idea for the Subaru to help haul its own speed down when the RV is braking.

I went with a combination tow bar with integrated braking system, the NSA ReadyBrute Elite.

The NSA ReadyBrute Elite tow bar
The NSA ReadyBrute Elite tow bar

Left end connects to the hitch of the RV, right ends connect to the base plate I installed on the Subi. Voila, ready to tow.

Where does the auxiliary braking come in? The ReadyBrute uses something called surge braking. It’s not a new concept by any stretch. Some people frown on it and call it a kludge. To me, though, being a purely mechanical system, it strikes me as the least likely to succumb to failure.

Here’s the theory: as the RV slows down the Subi keeps rolling forward. It compresses against a shock and spring in the ReadyBrute and at some point causes enough pressure to activate a lever on the ReadyBrute. That lever gets attached to a cable that gets attached to a cable on the front of the Subi that connects directly to the brake pedal. It pulls on the brake pedal causing the Subi to slow down. As equilibrium is reached — either the RV speeds back up or the Subi slows enough to no longer apply pressure — the lever stops being lifted and the cable slackens, letting the brake pedal back up.

There’s another aspect of braking and that’s emergency breakaway braking (supposedly there’s a law about that too). If the Subi ever gets completely loose while being towed, there’s a system that’s supposed to apply the brakes so it doesn’t cruise along forever until it hits something. Clearly this is an event of last resort as every connection between the RV and the Subi must have failed: the tow bar (rated for 8,000 pounds) failed, and the safety cables failed (rated for 6,000 pounds) failed, every connection between the Subi and the RV failed. Unlikely in the extreme, but anyway.

For that NSA sells a breakaway kit guided along similar principles: a cable attaches to the RV frame (not the hitch receiver but the actual frame) then gets attached to that red cable at the Subi which goes to a breakaway box mounted on the frame of the Subi and then straight to the brake pedal again. The difference here is that it’s a one way street: if the Subi ever breaks away from the RV, that cable gets pulled taut between the RV and the brake pedal, essentially, and it doesn’t allow the tension to release. There’s a shear pin that breaks off after a certain weight so that the brake pedal doesn’t get destroyed, but basically the brakes are left applied so that you can pull over and go back to your car sitting in the middle of the highway. There’s a release button on the breakaway box so that once you get control of the car you can release the brakes and move it out of the way while you figure out how you screwed everything up so badly.

So! This weekend was about wiring up the Subi with all of these delightful cables that attach to the brake pedal. Yes, I took the front off again. Yes, I got to spend quality time underneath the Subi again. This was a longer process, roughly 7 hours. Part of that was because of a misread of the directions.

I got pretty much everything done. It looked like this.

Yeehaw, I'm done!

I got the other end hooked up to the brake pedal and gave it a pull to try it out. Well, it pulled on the brake pedal as expected. As not expected it also pulled on the fitting, which pulled on the fascia, which pulled outwards. I really didn’t expect it to do that and it was far from ideal. Every time we towed, every time the brakes got applied that fascia and connection would be yanked out. Ugh. No.

I rethought. Took off the front of the car, looked for a place where I could install it in metal. Found one I thought would work to the right of the radiator. Tried it out and it fit. After further reflection and research I realized that the connection really needed to be as close as possible to the center of the car for a straight pull from the ReadyBrute lever.

Soon enough epiphany hit and I drilled a new hole in a crossmember under the radiator. The connection fit perfectly and after trimming a small notch in the air dam it was a go.

When the bumper cover is put back on you can see where the center black fascia fits. Perfect!
When the bumper cover is put back on you can see where the center black fascia fits. Perfect!

Even better, when not in use the loop can be hidden behind the black center piece of the fascia I previously tried to have it come out. Win win!

The emergency breakaway went a bit smoother though I thought it would actually be harder. The non-breakaway cable I just installed runs through a conduit from that mounting location to the hole in the firewall that you drill. That conduit means that the cable never really pulls taut while it cruises through the innards of wherever you put it. Sure, you have to be careful not to have it near either hot things or moving things, but aside from that it’s fairly straightforward.

Not so with the emergency breakaway cable. Remember, that’s a last resort “holy shit, the Subi is gone” type of thing. From the front of the car where that red loop comes out to the breakaway box will be pulled as taut as can be when the worst happens. Ditto from that breakaway box through the firewall and to the brake pedal. It’ll be pulled as taut as you can imagine. So anything delicate or crushable between those points will get squished pretty handily. Moral of the story: don’t run that cable where anything that can be damaged is.

I actually found a great location, right behind the driver’s side wheel on the frame.

That red box is the breakaway box.
That red box is the breakaway box.

From there to the front of the car is a straight shot along the frame coming up along the base plate to where you see it in the picture above. Similarly, from there to the firewall is a pretty straight shot with only the frame between.

Now all I need is an RV :).

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