What cause stiff brake pedal?

Posted by jumpfroggy, Feb 13, 2009
Newbie Forum - Beginner DSM modification questions and discussions. Common, repetitive, and general discussions will get dumped here from other tech forums. Unless you're a Probationary member you shouldn't post threads here.

  1. jumpfroggy

    jumpfroggy Proven Member

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    Jamestown, Rhode_Island
    I'm just curious. I've noticed a huge difference in the feel of the brakes from car to car. I've noticed that recent/modern economy cars tend to have very light & jumpy brakes... easy to press a little bit and cause the car to screech to a halt. On my 95 Talon AWD (and on my previous 95 Talon TSI), I've noticed that the brakes are fine when I press slow/gently... but when I slam on them, there's a whole lot of resistance.

    It reminds me of trying to fit fluid through a small hole... if you're going slow, it's fine. When the pressure builds, the hole is a bottle neck. I don't think this is abnormal stiffness from my brake (though I could be wrong), but I'm just curious:

    Why do DSM brakes have a lot of stiffness when pressed hard/fast? Is it something that can be changed? I've been wondering about this for a long time, and now I just want to know why it happens.

    Thanks all, can't wait till the weather stops freezing so I can fix that stinking wheel bearing hub (and brakes, and turbo, and...)
     
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  2. ClevelandDSM

    ClevelandDSM Proven Member

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    Its just a chain reaction from the master \ lines \ calipers , all with resistence.

    With no resistence = no stoping.
     
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  3. jumpfroggy

    jumpfroggy Proven Member

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    I'm assuming that most cars have master/line/calipers though... and the newer ones stop great with little resistance. What's the difference there? I'm just curious, I always wish my DSM had brakes like that.
     
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  4. juanpac0

    juanpac0 Proven Member

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    Variations in the brake boosters between cars would be my guess. Different brake sizes also call for different master cylinders.
     
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  5. crimsondragon

    crimsondragon Proven Member

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    There's a lot of variables to this. It could depend on the master cylinder and slave cylinder port sizes or the brake lines, different piston sizes and amount, brake bias, etc etc.
     
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  6. UGOT8UP

    UGOT8UP Proven Member

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    Is there problem with your brakes being excessive hard pedal, or are you just comparing you brake feel to a new car?

    If your pedal is very firm I would suggest to check out your brake booster.
     
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  7. jumpfroggy

    jumpfroggy Proven Member

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    It's not a problem right now, I'm just comparing my brake feel to a new car. I don't think it's the pads; if I press hard on the brake, I get resistance way before the brakes start to "take". On a new car, the pedal feel is easy whether I press hard or soft.

    Again, under normal usage I don't even notice it. But when I jam on the brakes, it's definitely a lot harder than other cars. I just keep wondering what causes that. Is it the way our cars are designed, or are parts worn?
     
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  8. UGOT8UP

    UGOT8UP Proven Member

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    I'm guessing that you have a problem, I've never noticed that on my car, If you have access to a vacuum pump test the booster to make sure that it is not bad.
     
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