Bryan Irons
The finished assembly of the Wilwood Electronic Parking Brake Retrofit system.
Words and Photos by Bryan Irons @bryanirons
Short of breaking into a ‘back in my day’ monologue, a time existed when the criteria I needed to deem a vehicle safe and reliable could have been written on a single post-it note – in large letters with a thick-tipped Sharpie.
Although heeding the advice of others is a sound theory, it took a friend of mine who ripped down a steep hill onto a highway crossroads without any brakes to make me change my thought process. From that moment forward, I now remind myself that safety in any project always begins with ‘stopping.’
A few issues ago, I wrote about installing an uber-fancy Wilwood Dynalite caliper and rotor kit on the back of our 1985-ish rock crawler, ‘Stinky Jeep.’ Although the kit was used, Wilwood is a top tier company when it comes to braking components, and their systems can bring a heavy trail rig to a dead stop on the fly. Nonetheless, there was a fly in the ointment; the Dynalite calipers do not include a parking brake.
Originally, the CJ’s of Stinky Jeep’s era had a foot-operated parking brake linked to a series of cables routed to the rear drum brakes. This system was adequate for the most part over the years and we had used it with little issue. But once we changed to rear disc brakes, things became a little more complicated. Different calipers with integral parking brake mechanisms were tried with very poor results. Either the calipers themselves were undersized or the parking brake didn’t work.
Once the Dynalite brake caliper setup was installed and I was happy with the performance of the main brakes, there was a lack of a parking brake assembly. Hydraulic parking brakes are available, but require another reservoir and lever assembly, not to mention legalities. Cable actuated units require maintenance and can become inoperable when the suspension is completely flexed out. Another challenge was finding the space to install an activation lever. So, I was very happy to see that Wilwood had a new electronic parking brake available to accommodate my needs.
Electronic parking brakes are not new among factory-equipped vehicles or even in the aftermarket. For a while, Stinky Jeep had a remote actuator that was tied into the factory cable driven parking brake assembly. It was short-lived and required constant adjustments. This wasn’t what we were looking for this time around.
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Wilwood’s Electronic Parking Brake calipers are not symmetrical. So, finding the ‘perfect’ position may be a little challenging. The target here was to keep them as high and out of the way of potential trail damage as possible.
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Although the caliper and pads are relatively small, the motor assembly is not. When figuring out the mounting positions, keep the electrical connector positions in mind.
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The CAD (‘cardboard’ aided design) process used here resulted in a bracket with three mounting bolts to keep it secure. All hardware used was common 3/8-24” from the caliper mounting to the brackets.
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After using a plasma cutter and belt sander, I had this to show for it. Bolting the brackets together ensured they were exact copies.
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Thin flat washers were used for any minor shimming to get the calipers perfectly centred over the rotor.
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All electrical wiring comes with quality connectors and the wires are labeled.
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Make sure to secure the wires out of the way of trail debris as best you can. Ty-wraps with a metal locking tab are best and we suggest you refrain from using the non-UV resistant ones.
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The electronic control module found a space under the hood on top of the driver’s side fender. We didn’t have a ton of extra cable with the kit, but unless you are planning on installing the kit in an extended Suburban, this shouldn’t be an issue.
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The included electrical switch is very clean and heavy-duty. It’s not often that I feel confident enough in a product to poke a new hole in the dash. You can tie the system into the factory e-brake indicator or use a momentary switch of your choice.
The new system from Wilwood can be ordered with a complete brake kit for your specific application, but since the Dynalite’s were already in the CJ, the stand-alone kit was ordered through Summit Racing for approximately $1,250 CAD (PN 140-15979).
The Wilwood Electronic Parking Brake Retrofit system has all the basics including calipers, pads, a wiring harness, plus a controller and switch. Specs from Wilwood’s manual state the rotors need to be between 2 cm (0.81 in) and 3 cm (1.10 in) thick and many vented rotors fit within this size constraint. What we had to do was figure out a bracket to mount the calipers to the rear rotor setup.
As I mentioned, a complete brake setup from Wilwood comes with the brackets to mount the Electronic Parking Brake. But for the CJ, it was simpler to make them. I slowly whittled down some MDF until a bracket appeared. The bracket had to be large enough to handle the strain it would be subjected to, mount to some of the existing bolt holes in the Wilwood bracket that attach to the axle flange, and properly position the bracket as outlined in the instructions.
The template was then transferred to a couple of pieces of 5/16” thick aluminum plates. This is the same thickness as the brackets that came with the Dynalite caliper kit. After cutting, grinding, drilling, and smoothing, it was time to bolt the assembly together.
Bolting everything together involved a little head scratching, but I am pleased with the results. Some longer 3/8” fine thread grade 8 cap screw bolts were scooped from the local bolt supply house. While paying through the nose, I decided to subject myself to more pain and purchased some thin 3/8” stainless steel flat washers to use as shims for fine adjustments. Loctite is a must here and red high strength is what was used.
Very little is needed to wire the Electric Parking Brake as it comes from Wilwood. Starting from the calipers, the watertight connectors fit nicely and there was plenty of length in the harness for multiple setups. The controller was small and was placed under the hood. There was no need to worry about water or dirt ingress, and the potted electronics can handle the temperatures.
However, I had to solder the final electrical connections to the included control switch. A connector would have been nice, but not having to fish a bulky connector through the firewall and being able to trim the harness back as needed was an advantage. Crimps could also have been used.
After the connections to the battery and a switched source were made, it was time to enjoy having a working parking brake. There is no setup or adjustments required. When activated, the electric motor in each caliper activates until they lockdown on the rotor. Once they are locked to your satisfaction, the control switch’s red indicator lamp comes on while the key is in the “on” position. If you have a problem (I forgot to hook up the ground wire on the first run), the lamp will flash in a sequence for easy troubleshooting.
There seems to be a hint of fear with many people concerning electronic parking brake systems despite being used by OEM’s with great success. The Wilwood’s kit is very well made. The holding pressure is fantastic, and actuation takes very little time. Overall, I wish this system was available years ago rather than always looking for a large rock to throw under the tires while out on the trail. Follow us along as the CJ is transformed from a Tik-Tok video in the making to a rig with solid stopping power.
For more information visit www.wilwood.com or www.summitracing.com.