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IS THERE A BRAKE PROPOTIONING VALVE FOR SIDE TO SIDE?

Discussion in 'Gen 3 Prius Technical Discussion' started by Dale Earnhadrt, Apr 27, 2015.

  1. Dale Earnhadrt

    Dale Earnhadrt Junior Member

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    I KNOW THERE ARE BRAKE PROPORTIONING VALVES THAT CONTROL FRONT VERSUS REAR BRAKE PRESSURE. I WAS WONDERING IF THERE IS ANY WAY TO ADJUST DRIVER SIDE VS. PASSENGER SIDE. HERE'S WHY:

    PUT NEW REAR ROTORS/PADS IN MY 2010 PRIUS. PASSENGER SIDE WAS FINE...PLENTY OF PAD LEFT. DRIVER SIDE WAS DOWN TO THE BACKING PLATE WITH ZERO PAD LEFT.

    SO NOW, WITH ABOUT 200 MILES ON THE BRAKE JOB, I NOTICED THE DRIVER SIDE ROTOR IS SHINY AND HAS A DEFINATE WEAR PATTERN ON IT WHERE THE BRAKE PAD RUBS ON IT. THE PASSENGER SIDE ROTOR STILL HAS THE CROSS-HATCH MACHINE MARKS ON IT AND DOESN'T LOOK LIKE ITS BEEN TOUCHED BY THE BRAKE PAD.

    MY DRIVER SIDE REAR BRAKE IS GETTING WAY MORE PRESSURE THAN THE PASSENGER SIDE. ANY WAY TO CORRECT THIS?
     
    #1 Dale Earnhadrt, Apr 27, 2015
  2. ChapmanF

    ChapmanF Senior Member

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    try typing in all lowercase for the next 200 miles or until the wear patterns appear to match. Then, you can type in ordinary mixed case from that point, and the wear should stay even.

    Or, seriously, the wear pattern you are seeing probably reflects binding or misadjustment of the calipers. Can you describe in any more detail what work you did on the calipers at the same time that you changed the pads and rotors?

    I've seen several references to making sure that the pad pins are properly engaged with the piston recesses after everything is back together.

    -Chap
     
    #2 ChapmanF, Apr 27, 2015
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  3. bisco

    bisco cookie crumbler

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    seems like with only 200 miles, you shouldn't be seeing anything at all, unless you hit the brakes hard and often. i would think the shiny one is dragging.
     
    #3 bisco, Apr 27, 2015
  4. Dale Earnhadrt

    Dale Earnhadrt Junior Member

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    what would cause dragging? Bad caliper?
     
    #4 Dale Earnhadrt, Apr 27, 2015
  5. xliderider

    xliderider Senior Member

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    Or dragging/binding on the slide pins.
     
    #5 xliderider, Apr 27, 2015
  6. ChapmanF

    ChapmanF Senior Member

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    Can you describe your steps when you replaced the pads and rotors? There were signs at that time of accelerated wear on the driver side. What did you do to investigate while you had them apart, and what did you find? Just so we don't go back over what you've already checked.

    -Chap
     
    #6 ChapmanF, Apr 28, 2015
  7. Dale Earnhadrt

    Dale Earnhadrt Junior Member

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    Good question. The piston went back into the caliper without issue. I didn't see anything out of the ordinary. What would you have been looking for?
     
    #7 Dale Earnhadrt, Apr 28, 2015
  8. Dale Earnhadrt

    Dale Earnhadrt Junior Member

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    I cleaned and lubricated the slide pins. Didn't see any signs of binding. Maybe I'll replace calipers and pins. I'd rather not. Prius rear calipers are expensive. I just bought calipers for my Dodge Ram Cummins Diesel and they were half the price of rear Prius calipers.
     
    #8 Dale Earnhadrt, Apr 28, 2015
  9. bisco

    bisco cookie crumbler

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    see mendel leisk's work on the rear brakes. he has a great write up, and all sorts of inside knowledge.
     
    #9 bisco, Apr 28, 2015
  10. Dale Earnhadrt

    Dale Earnhadrt Junior Member

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    Did a search "mendel leisk rear brakes" and returned only my post. How would I find Mendel's stuff?
     
    #10 Dale Earnhadrt, Apr 28, 2015
  11. bisco

    bisco cookie crumbler

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    i think you can just put his name in the member section, and do threads only.
     
    #11 bisco, Apr 28, 2015
  12. bisco

    bisco cookie crumbler

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    i put his name in, checked thread titles only. he's a prolific poster, so a lot comes up. the i put in the word brake, and only 5 came up. you could try brakes and see what happens. searching can be hit or miss. it might be easier to pm him, he's really helpful and knowledgable, and he's posted a lot of brake pics.
     
    #12 bisco, Apr 28, 2015
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