Rear brake proportioning valve with 3" drop EASY FIX

Discussion in 'Suspension/Chassis' started by furious, Sep 11, 2015.

  1. furious

    furious Newbie

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    I thought I'd post what I've done to correct the rear proportioning valve problem that happens when you lower the rear of a Toyota. I've seen others on here that go to extremes with all sorts of ideas. Having only low pressure was NOT an option as I'm only lowering this truck 3" and it may be used to haul a load some day. The valve needs to work.
    Here's what I came up with on my '94. Simply flip and turn around the top bracket that holds the rod to the adjuster. Then turn down the adjuster all the way. Then remove the mount and reposition it down making the top hole line up with the bottom hole on the rear end. A small notch will need to be cut on the rear end mounting side to allow the bottom bolt to be installed. Use a nut on the backside to hold it in place.
    Walla! You're done, it has been adjusted exactly 3" and didn't cost a thing.

    Full build thread is in the works as soon as I get paint on it. Interior with Honda seats, RX8 wheels, stereo, suspension adjustments, and bodywork and paint. I should be done in a week or two. Stay tuned.
     
  2. White Trash

    White Trash Toyotaholic

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    Or just grab a hold of the rod and yank down so it over cams and stays in the low position. :lol:

    [​IMG]

    The valve really doesn't make that much of a difference in braking power from top to bottom position. If you remove it completely the rear will get more pressure than it is able to get even when maxed out as if you were hauling incredible weight and the rear will tend to lock under hard braking.
     
  3. MrDinkleman

    MrDinkleman Addict

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    I was thinking you can just bend the rod. No?
     
  4. furious

    furious Newbie

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    YIKES! That looks like something one of my stoner friends would have built back in '89. Is that you Kevin? ;)

    Yes, the valve absolutely does make a noticeable difference. If you have high pressure only then you're going to crash if you brake under an emergency situation. The rear tires lock up and you will slide instead of stopping. If you have only low pressure then you wont stop at all when hauling a load. Toyota engineers didn't design it for no reason. It's a very useful safety feature and anyone with any real mechanical knowledge would look for it to be properly adjusted in a resale situation.
     
  5. furious

    furious Newbie

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    Sure, but you really need to remove the rod from the valve to do that safely. Bending it while still connected to the valve can put negative pressure against the valve and cause it to leak or even get stuck.

    Again, most people who know what the valve is would not want to see the rod bent in a resale situation.

    ..
     
  6. White Trash

    White Trash Toyotaholic

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    Meh not all toyota trucks even came with the adjustable valve. Some had either a proportioning valve mounted under the master cylinder or no proportioning valve at all.

    This is my DD, scrap hauler and weekend autocross truck and it stops perfectly even with the valve setup as is. I run 265's out back, I swapped on a set of 205's awhile back and the rear would juuuuust start to lock up under hard braking. With the 265's it just stops, no drama. I have a wilwood adjustable valve to plumb in when I scrap the current valve but I won't have time to do that till next month.

    No need to fear the chains holding the axle. They were there to hold it at ride height so the sway bar links were lined up with the bar so it works properly. Don't get too caught up about my mechanical knowledge either, it's all learned by doing things myself not from reading about it online. ;)
     
  7. MrDinkleman

    MrDinkleman Addict

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    That's true. Didn't think about that since I never sell my cars...
     
  8. White Trash

    White Trash Toyotaholic

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    Yup my rigs get abused until I finally take off anything good and scrap the leftovers more often than not. :lol:
     
  9. redman

    redman Enthusiast

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    Don't get too caught up about my mechanical knowledge either, it's all learned by doing things myself not from reading about it online. ;)[/QUOTE]

    White Trash, That's sum good stuff right there ! Me like :waytogo:
     
  10. Juicyy

    Juicyy Member

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