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Metcalfs Electric Emergency Brake Kit

Discussion in 'Early CJ5 and CJ6 Tech' started by jeepstar, Feb 2, 2021.

  1. Apr 16, 2021
    Jeepnjesse

    Jeepnjesse New Member

    Where the beer...
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    Ended up having to swap my master because mine was bad. Used this one from napa because it had a small boar.82(it was only $26.79 on sale) and now can lock up all 4 wheels on pavement I also have a nice brake pedal feel. The E Brake still works great though I did upon reassembly cross the wires to lock one wheel while releasing the other. Problem solved now. Over all I am really impressed with the set up. The only thing I wish I did differently was to replace everything at the same time instead of banging my head into the wall with a bad MC.
    [​IMG]
     
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  2. Apr 28, 2021
    supertrooper

    supertrooper Member

    moreno valley, ca
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    I have my kit installed and im waiting on a switch and circuit breakers to finish wiring them up. Question is, is it possible to have a dash mounted light turn on when the parking brake is on when using a momentary switch? It would be nice to have an idiot light to remind me its still engaged before trying to drive off.
     
  3. Apr 28, 2021
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
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    Looking at earlier posts, it looks like there is no feedback from the caliper about position.

    If you pick the right switch, you can latch up a relay connected to your indicator light. You'd need to arrange some way to break that relay power when you switched off the brake, either through a specially designed switch or another relay. Could be done.

    Working on a sketch - no time right now, Zoom meeting at 10AM.
     
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  4. Apr 28, 2021
    Oldpappy

    Oldpappy A.C. Fults - Curmudgeon at large 2022 Sponsor

    East Tennessee
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    So, it would seem that with two switches you can activate each brake independently. If so, this is certainly an advantage. Sort of a poor man's locker.
     
  5. Apr 28, 2021
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
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    Here's a drawing of how an indicator light might be done using two relays:

    BrakeCircuit (573 x 320).jpg

    You have two momentary contacts, one each for brake on and brake off. Press brake on and that energizes relay 2 and turns the light on. The relay then powers its own coil and is latched on. Press brake off and that closes the first relay, cutting power to the second relay and turning the light off.

    This has a problem - you turn the ignition off and the light goes out, and does not come on again when you start up. There has to be a latching relay or such that remembers its last state. I will look.

    Later - this should work. It's a latching relay, with two coils.
    RT314F12 TE Connectivity Potter & Brumfield Relays | Relays | DigiKey

    One coil swings one way, the second swings the other. With coil connections [A1, A2, A3], A3 is common. Apply power between A3 and A1 gives you the closed state, and between A3 and A2 the open state. Should be easy to connect this to your brake switches and power an indicator light. This relay will remember its state without constant power.

    Looking at this a little more, the data sheet says the device is magnetically polarized, and the single coil version depends on the polarity of the coil for switching. This dual coil version shows positive (+) as common, and ground as switched, which is unfortunate. Possible the two-coil version will work regardless of polarity, don't know. If not, you'll have to arrange some way to reverse the controlling polarity from the brake selector. Maybe a couple of transistors?
     
    Last edited: Apr 28, 2021
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  6. Jul 23, 2021
    Aidan Turner

    Aidan Turner New Member

    Morristown, NJ
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    It's been a few months, how do you guys like this set up?
     
  7. Jul 23, 2021
    garage gnome

    garage gnome ECJ5 welder

    Western MA
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    Love it!
     
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  8. Aug 23, 2022
    BrianS

    BrianS New Member

    Kalifornia
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    Old threads have great research value.
    I’ve had my eebrake installed for 4 months now. I have it wired with a HD SPDT momentary switch, down to lock, up to release. I push it down 4 quick clicks to clamp and 4 up to release. The only indicator it’s off is if my Jeep will move. Only wire it with switched power! You wouldn’t want it to get bumped while out of the vehicle and it roll away or released and stolen. I wired it through 10A resettable circuit breakers and find it locks solid before I get them to pop. I’ve never had a real parking brake and glad the 4x4 wood one is out!

    Should the brake be set and the battery die, use a power tool battery to power the parking brake off at the unit. Chock the wheels! Unplug it, clip on 2 leads, touch to battery. If it doesn’t move, reverse the wires. Go to other side, repeat.

    You will need to do this when removing from a wrecked vehicle as the computer locks the brakes upon impact. Purchase 316 marked brackets only.
    5B8404D1-01C7-4EB9-86C7-2BD1223E2B40.jpeg
     
    Last edited: Aug 23, 2022
  9. Sep 2, 2022
    justin_bongo

    justin_bongo Member

    Pampa, TX
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    How tight should these calipers sit at rest?
    I can apply 12v to lock caliper down, and then 12v to release it, but it still seems like its tight. Rear axle on stands, running jeep in 1st gear, it seems like its dragging quite a bit. I can't turn rotor by hand when unlocked.
    Do I need to just drive it some to wear in parts?

    Thanks,
    JT
     
  10. Sep 2, 2022
    47v6

    47v6 junk wrecker! 2023 Sponsor 2022 Sponsor

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    If its dragging, it will create a lot of heat that will lock up your brakes.. Make sure your caliper is fully centered over the rotor.
     
  11. Sep 2, 2022
    supertrooper

    supertrooper Member

    moreno valley, ca
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    Something isnt right if you cant turn the rotor by hand with the brakes released. Can you tell what parts of the bakes are dragging? Is the caliper centered over the rotor? How are you switching the parking brake on and off?
     
  12. Sep 2, 2022
    justin_bongo

    justin_bongo Member

    Pampa, TX
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    I wired up 4 relays to switch + and - to motors.
    I can tell the motor sets the brake by seeing the pads tighten, then when I switch it to (off), it run the motor all the way back till it stops.
     
  13. Sep 2, 2022
    justin_bongo

    justin_bongo Member

    Pampa, TX
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    I'll take another look and make sure its still centered. Doesn't the caliper somewhat float on the pins?

    JT
     
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  14. Sep 2, 2022
    47v6

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    Yes, calipers do float, but from my experience, if they allow even a bit of drag, they heat up and expand the fluid.
     
  15. Sep 2, 2022
    Jw60

    Jw60 Sitting up n buckled down. 2024 Sponsor 2023 Sponsor 2022 Sponsor

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    This brings up a good point, are we sure the residual pressure valves are replaced with 2lb valves? Any expanded fluid should push past the RPV and back to the reservoir.
     
  16. Sep 2, 2022
    justin_bongo

    justin_bongo Member

    Pampa, TX
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    I dont have the brake system bled yet. I did install a Toyota corolla master, which as far as I can tell has no valves in it. I did install 2 lb valves in lines.
     
  17. Sep 2, 2022
    justin_bongo

    justin_bongo Member

    Pampa, TX
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    It looks like the stud on the back pad that rides in the slot on caliper center sheered off. Not sure if that would cause this , but I'm pretty sure that would not let the screw retract correctly and hold tension on pads.
     
  18. Sep 2, 2022
    justin_bongo

    justin_bongo Member

    Pampa, TX
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    I figured it out. The company i bought the calipers from function tested the motors, and I think they ran the pistons out too far. There are a bunch of springs and ball bearings in them that got all messed up and wouldn't let the piston collapse all the way. Had to order replacement calipers.
     
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  19. Sep 3, 2022
    justin_bongo

    justin_bongo Member

    Pampa, TX
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    Question, I got my new calipers installed, bled brakes, had a soft pedal, bled some more, found more air, got a good pedal. Went for a drive, did a few accelerations, and a few hard brakes just to make sure. All felt good, or so I thought. Jeep acted like it was losing power all of a sudden, found brakes dragging bad. Would the 78 corolla master do that?
    Searching on Rockauto, it looks like they had disc/drum. Would it have a residual valve for rear?
    If so, how do I defeat it?

    Thanks,
    JT
     
  20. Sep 4, 2022
    supertrooper

    supertrooper Member

    moreno valley, ca
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    The drum residual pressure valve will needs be removed and replaced with a 2 pound disk brake valve. Not sure if its removable in a corolla master but if it is you can add an inline pressure valve from wilwood as close to the master as possible. Another option is a disk/disk master.

    To remove the pressure valve in a gm master you disconnect the brake line for the rear circuit from the master. Then carefully screw in a drywall screw in the hole of the brake line seat and pull out with pliers. The valve and spring should then come out. Replace the seat and brake line then add inline pressure valve.
     
    Last edited: Sep 4, 2022
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