Stiff Brake pedal
Mar 31, 2014, 07:12 PM
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Stiff Brake pedal
My Evo has a very stiff brake pedal. I need to get this fixed. I don't expect air in the lines since that is usually found in mushy pedals and I have the opposite of that. Fluid is good, calipers are not sticking so I am trying to diagnose the problem
So after reading multiple threads on the topic. Here is my conclusion:
The stiff pedal is caused by lack of vacuum. It is yet to be determined if this is the booster or the line.
I took the vacuum line off that connects the booster to the intake manifold. the check valve inside is definietly working only in one direction. I ran the car with a standard vacuum line in its place and the car idled roughly and even shut down when rolling to a stop. this rules out the line but it also leaves me wondering what that means about the booster.
I don't want to blindly replace the booster mainly because I don't want to have to bleed the system at home.
Any input?
So after reading multiple threads on the topic. Here is my conclusion:
The stiff pedal is caused by lack of vacuum. It is yet to be determined if this is the booster or the line.
I took the vacuum line off that connects the booster to the intake manifold. the check valve inside is definietly working only in one direction. I ran the car with a standard vacuum line in its place and the car idled roughly and even shut down when rolling to a stop. this rules out the line but it also leaves me wondering what that means about the booster.
I don't want to blindly replace the booster mainly because I don't want to have to bleed the system at home.
Any input?
Last edited by Japsfinest; Mar 31, 2014 at 08:22 PM.
Apr 1, 2014, 09:01 AM
#2
Has it always been stiff or is this something that you started noticing recently? Reason I ask is because my evo has always had a stiff brake pedal. I actually prefer it how it is as I find it to be quite linear and allows me to modulate the brakes easier than some cars which I find to have very touchy brakes. A lot of this is a function of the pads, lines fluid etc but nonetheless my car has always had a stiff pedal.
So, I'm curious if there is indeed an issue or if its just something you're not used to. If there is a mechanical issue the brake booster would be my first thought which it sounds like you are already well aware of. But before you go throwing $ and time at it I'd confirm that it's not normal in the first place.
So, I'm curious if there is indeed an issue or if its just something you're not used to. If there is a mechanical issue the brake booster would be my first thought which it sounds like you are already well aware of. But before you go throwing $ and time at it I'd confirm that it's not normal in the first place.
Apr 3, 2014, 05:56 AM
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Update: I have decided to change out both the booster and the Master cylinder. This job is being completed by shop today since I don't have a pressure bleeder and don't feel like pumping the brake for several hours to bleed old school style.
Hopefully this afternoon the car will stop on a dime.
Hopefully this afternoon the car will stop on a dime.
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