Question on brakes

Discussion in 'Suspension, Steering, Brake & Wheel Topics' started by ULTM8Z, Dec 24, 2017.

  1. ULTM8Z

    ULTM8Z Veteran Member

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    May 19, 2000
    Los Angeles
    So I have had my Baer system since about 2000. Literally one of the most reliable parts of the car... other than changing the pads a couple of times and turning the rotors for the first time last year (after one of the fronts finally developed a shimmy).

    It was a complete system... front and rear rotors/calipers, 9" booster, master cylinder, prop valve. The only thing I changed in the system was using a WS6 Firebird 4 wheel disc prop valve instead of the valve in the kit with adjustable rear valve.

    The issue is I'm noticing that the pedal is having to go quite a distance before the brakes engage. I have about 12 inHg of vacuum at idle, which seems a sufficient amount of vacuum. But with the engine on, it seems like I'm about 3/4" of the way down on the pedal to hold the car at idle with a fair amount of foot pressure on the brake pedal.

    My wife's Infinity QX60 goes about ~1/4 the distance before the brakes fully engage. My '06 Pontiac Vibe is roughly the same as the Infinity.

    Since it's been so long since I've had my system on the car, I literally can't remember what it felt like new... lol. But for a system that's essentially equivalent to a C4 Corvette, I guess I'd expect it to be a little better.

    Now, with the engine off, the pedal is rock hard after just a small amount of movement. Seems like that should be correct and indicate that the there are no leaks in the master cylinder seals?

    When I shut the engine off, after waiting a few minutes, I pull the check valve off the booster and it makes a loud "woosh" sound, which seems like it would mean it doesn't have any leaks.

    Again, after 17 years without really having to think about it, I don't really remember what this thing felt like when new.

    The one odd thing I noticed though...

    I went around bleeding the brakes yesterday. I used an electric vacuum pump, but man, the air bubbles would not stop coming out. I pulled quite a bit of fluid through the system so I figured it was bled well enough and that the air bubbles were coming from the connection to
    the bleeder valve. But overall there was no change in pedal behavior.

    The car still stops well, so I'm not sure what to make of it at this point. Maybe it's just the way it is. In which case, what can I do to improve it? Hydraboost is not an option... too much $$$$....
     
    Last edited: Dec 25, 2017
  2. NOT A TA

    NOT A TA Veteran Member

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    Feb 12, 2009
    Delray Beach Florida
    The bubbles are probably due to air sucking around the threads of the bleeder when you open it which can cause a consistent flow of very tiny bubbles when using suction.

    What rear calipers do you have? Do they have a park brake? Some rear calipers require the park brake cables to be properly adjusted or the pistons retract too much as the pads wear. This results in long pedal stroke.

    For booster/master combos GM used a couple different booster rods that actuate the master cylinder. Perhaps you have a short booster rod where the master you are using requires a long rod. This would cause a long pedal throw before pad contact. You could split the master from the booster enough to take a peek without disconnecting any lines.

    Don't know if you used a 4 wheel disc pedal or a disc/drum pedal and it's also possible that an adjustable rod for the pedal clevis could shorten the pedal travel before initial bite. The amount of force needed on the pedal to have the brake "feel" correct and have good stopping power will depend on the proportions of the pedal assembly with relation to pedal length and distance of clevis point from pedal rotating point and piston diameter of master cylinder.
     
  3. ULTM8Z

    ULTM8Z Veteran Member

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    May 19, 2000
    Los Angeles
    Hmmm.. it's been so long, I really don't recall what booster rod is in there. It's whatever came in the Baer kit most likely. I would think they would have put compatible components in the kit.

    The pedal pushrod has some adjustment nuts on it. Maybe I need to lengthen it?

    I do know the pedal is the stock pedal. It has a manual brake pushrod hole and a power brake hole. I'm using the power brake hole. Though i was unaware there was a difference between 4 wheel disc and disc/drum. The car was originally disc/drum, so that's the pedal I'm running.
     
  4. CorkyE

    CorkyE Veteran Member Lifetime Gold Member

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    Nov 4, 2004
    Ringgold, GA
    Learning something new all time. I didn't know there was a different pedal in the Camaro for a disc/drum and disc/disc setup. I recently installed the Right Stuff rear disc and from what I understand, it uses and early Caddy Escalade setup. You definitely must have the park brake setup correctly for the rears to work.
     
  5. Zspoiler

    Zspoiler Veteran Member

    Have you talked to Baer recently ?
     
  6. ol' grouch

    ol' grouch Veteran Member

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    Jul 4, 2013
    Evansville, In.
    How old are the flex hoses? One in the rear and two up front. If one is reaching the end of its service life, it can cause a spongy pedal. You definitely shouldn't go 3/4 of the way down before the brakes engage.
     
  7. NOT A TA

    NOT A TA Veteran Member

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    Feb 12, 2009
    Delray Beach Florida
    ol' grouch may be onto something particularly if the rear flex line wasn't replaced when the rear disc install was done. I've seen front/rear disc kits that were sold with hoses for all four calipers but the one from body to rear axle isn't included in kit.

    I have seen where the adjustable clevis rod loosens up if the nut wasn't locked tight enough. The rod becomes ever so slightly shorter each time the pedal is pressed and very slowly over many many brake applications the pedal stroke increases.
     
  8. Skip Fix

    Skip Fix Veteran Member

    2,007
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    Mar 21, 2007
    Katy,Texas
    Yes the 9" dual diaphragm booster for the 79-81 TA 4WD is much more efficient than the 11" single on the disc/drum setup so the factory decreased the ratio. I did not swap my pedal on my 78 when I first did the swap, stopped good just no pedal feel. Luckily that was back when the were still available at the dealer to buy the 4WD pedal.
     
  9. NOT A TA

    NOT A TA Veteran Member

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    Feb 12, 2009
    Delray Beach Florida
    Skip did the 4WD pedal reduce the pedal stroke enough to notice?
     
  10. ULTM8Z

    ULTM8Z Veteran Member

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    May 19, 2000
    Los Angeles
    I plan to after Christmas is over. Just wanted to pick all of your brains as well.
     

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