Got No Brake Fluid going to my back wheel--Any ideas??

Discussion in 'Troubleshooting & Diagnosis' started by 75LTCAMARO350, Oct 29, 2007.

  1. 75LTCAMARO350

    75LTCAMARO350 Member

    75
    0
    Apr 5, 2007
    Houston, TX
    OK---braking was very weak---when I pulled the back drivers wheel --I saw brake fluid coming out of the wheel. cylinder and some fluid on the brake shoes.

    I disconnected the brake line behind the wheel and not much fluid came out.

    I put a new whl. cylinder in it. went to bleed the wheel and no fluid is going to this wheel. Any ideas on what is causing this?

    Is there some kind of a pressure or proportional value I need to push? I looked for one but did not see any.

    My next step is to check the Pass. rear wheel's cylinder's condition and if this wheel is getting fluid.

    Thx in advance!! Mark
     
  2. tom3

    tom3 Veteran Member

    10,630
    41
    Aug 1, 1999
    ohio
    Up front under the master cylinder is the proportioning valve, on the ends are rubber caps with a little pushbutton underneath. Try pushing in on the rubber and maybe it will open it up. You did check the brake fluid level, LOL. Might be a bad hose from the body to the rear in the center of the car over the rear end, not common but they do deteriorate and stop up.
     
  3. Phil G

    Phil G Veteran Member

    665
    6
    May 3, 2004
    Tucker, GA, USA
    This is similar to my '76 Monza as they used the same design in the brakes.

    What you need to do is take the rubber cap off the porportioning valve and make a tool to keep the pin in the center of the valve in place.

    I made one out of a piece of scrap steel.

    Then bleed the brakes. After fixing the leaky wheel cylinder, and new shoes, and cleaning/machining the drum...

    Brakes are a PITA.

    :rolleyes:
     
  4. yoyo74

    yoyo74 Veteran Member

    539
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    Jan 3, 2007
    Wallkill NY
    what does work after all else fails and trust me it is a pain in the ass to reset this proportioning valve.....Take the swith for the brake warning light out and as you look down inside take a very small screwdriver or a tranny pic and slide the valve either left or right to the center position.Now that part is fixed.Next dont touch the brake pedal until you let the rear brakes gravity bleed for a few minutes.I found this after I replaced mine because It just wouldnt reset.Once I got the old one on the bench I took it apart and tht is all there is to it.A plunger assembly that simply slides left or right to redirect the fluid incase of a major line leak..hope this helps
     
  5. 75LTCAMARO350

    75LTCAMARO350 Member

    75
    0
    Apr 5, 2007
    Houston, TX
    OK ---where is the proportioning valve located? I looked and only saw a rubber boot top with a wire coming out of it. --- Is this the low fluid brake warning light warning sending unit? correct???

    Is this where the brake warning light switch is located? If not where is this?

    any pics? Thx!!!
     
  6. SG71SS

    SG71SS Veteran Member

    The prop valve is right under the master cylinder. The brake warning light plugs into the top of it. you will see the fluid lines from the master cylinder going to it and the brake lines going out to the front and rear brakes. You can't miss it.

    Here's a picture from another type of car but the location is similar on a Camaro:
    [​IMG]
     
    Last edited: Oct 30, 2007
  7. kain13

    kain13 Veteran Member

    519
    0
    Jul 6, 2006
    Lubbock,Texas
    dont forget that ruber line in the back by the rear diff that can swell shut
     
  8. 75LTCAMARO350

    75LTCAMARO350 Member

    75
    0
    Apr 5, 2007
    Houston, TX
    THX Sal!! Great pic! I did see this valve and saw the boot with the wire coming out. But, that was all. I did not see any reset button or switch on it.

    Now ---how would I reset this brake prop. valve? To get fluid flowing back to the rear brakes again?

    I think the valve shut down the flow---due to the back wheel cylinders leaking.
    I have replace one wheel Cyl. Will do the other this Weekend.

    THX 4 all the info from U all!!
     
  9. Chuck 706

    Chuck 706 Veteran Member Lifetime Gold Member

    292
    0
    May 15, 2003
    Hastings, NE USA
    You're on the right track
    The valve is under the rubber boot on the engine side on my 76. I used a Quick Grip like you use on wood to hold it in while I was bleeding mine. See if this helps. I should have some more pictures somewhere.
    http://i168.photobucket.com/albums/u167/ChuckFarmer706/DSC_7562.jpg
     
  10. tom3

    tom3 Veteran Member

    10,630
    41
    Aug 1, 1999
    ohio
    Somebody mentioned this before, but you can fill the master cylinder, open the bleeder screw on each side and wait, fluid will flow through the lines and out after a while, then you can bleed normally with the pedal to get out any trapped air if needed. I use a vacuum pump to bleed the lines, really works.
     

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