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Linear actuator parking brake

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    I was thinking about this last night. You could use a park switch on the column to set the parking brake. Put it in park and it applies power to set the brake. Take it out of park, and it reverses to unlock the brake. Youd need a reversing circuit, since the motor needs its power/ground reversed. Then you need something to kill the power once it reaches its full travel, in either direction. I was thinking a junkyard window-auto-down module (such as what was found in the taurus/probe) would be an easy way to do that. Then in theory youd just need a DPDT switch on the column to reverse the power to the caliper. As a failsafe you can wire in a kill switch to the circuit, which would then leave the caliper in whatever position it was in when you flip the switch.

    i suppose a simpler way to do it would simply be a momentary DPDT switch on the dash and you can just press it when you want the brake set or released, but i like the idea of it being automatic in park so someone (like my wife) doesnt try to drive it with the brake set.

    I really like the idea of an electric pbrake, and since i need to put new calipers on the rear of my bronco, id like to get something along these lines working, instead of el dorado calipers.
    88 bronco // 96 bronco // 96 f250


      Drill a hole in floor, install Johnson Bar hand brake. Crawling without a clutch is lame, crawling without a Johnson Bar seems less fun. I use the hand brake pretty regular in da rocks. It's helps make Sami guys look like they have skills.

      Oh and with an open rear and a hand brake you can grab a spider to lock the rear for one rotation, Find an old school Truck Driver to show you how.
      Last edited by crisbee1; 2 days ago.


        One complication is that you don't want to drive the motor to the stop when releasing the brake if using a combined hydraulic/E-brake caliper, that would fully retract the piston. I suppose you could just pump up the brakes every time, but that might be pretty annoying. I believe even the separate Tesla calipers just have a timed period to release the brake, though they do have 2 separate wires for some sort of position feedback, it could be used without them.
        89 Toyota Pickup


          As I recall (been many years) the Johnson (on the right side of steering column, class 8 tractor) bar only applied the trailer brakes.

          I dont like the idea of a threaded rod as linkage to my np205 parking brake either and had in mind an air cylinder of the correct bore and stroke to set the parking brake and maybe another shorter cylinder to release it.


            Been dwelling on this whole electronic park brake thing. Theres a couple different companies out there that make elec pbrake kits, including Wilwood. Most of them are expensive, and it only gets you a park brake, nothing else.
            I was digging around and found a company called estopp, who make an electric conversion for traditional brakes:

            So since im already set up for GM calipers i could just buy new ones from ruffstuff, and use this to actuate them instead of the traditional foot pedal. Seems like an expensive way to set the brake when i can just push the floor pedal, and the el dorados can be a huge pita. If im gonna spend that kind of money on a parking brake, id rather have something that actually works reliably
            So then i started looking at OEMs. I like the idea of the 2018-20 F150 medium duty calipers over the Tesla because its a decently sized hydraulic caliper with electric park brake built in, whereas we'd have to use the tesla caliper as a dedicated park brake. Also, because (if you can find a core) you can get remans on the caliper bracket, for $46.33 from carid:

            of course you still need the actuator, and pads. The actuator costs more than the caliper, no surprise there:

            Now of course we still need to make them work. As Stephen Wilson pointed out, you cant just wire the caliper to run, it needs to stop once clamped, and it needs to retract but only a little. So we need a current limiting circuit to set the brake, and (arguably) a momentary to release it. I dont have an electronics degree or anything so building a controller myself is out. But then i found this:

            Its a 12v actuator, auto reversing, and you can set & adjust a current limiting stop, or use a physical limit switch. I think this would handle it. Itll accept either momentary or continuous input to operate the motor. I was originally thinking DPDT momentary switch on dash, but i think it would be possible to use method 2 (2 button momentary) to fully automate it thru the steering column, so that itll set the brake when you put it in park, and release as soon as you shift out of it.

            Link to PDF instruction sheet:

            Thoughts? While this seems feasible, i cant decide if its actually a good idea or not for a 'wheeler.
            Last edited by reptillikus; 16 hours ago.
            88 bronco // 96 bronco // 96 f250


              I like the idea, but I don't like the fact you need 2 of those controllers, so between that and calipers you're already at $500. Not necessarily a deal breaker, but I would like a slightly cheaper, neater solution. You can get calipers on Ebay for around $100 each.
              89 Toyota Pickup


                Yeah I know, that part kinda sucks. Its an expensive solution to a problem Id be creating for myself. I still have time as I doubt I'll get to brakes before October, so I'm going to keep digging around to see what else I can come up with.
                Last edited by reptillikus; 15 hours ago.
                88 bronco // 96 bronco // 96 f250