Thread: Brake booster
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Old 17th August 2016, 23:07
Mike Mike is offline
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Originally Posted by Nigbo View Post
I have already shortened the adjuster once. I originally set it up pretty close to no gap. Have shortened it by 4mm and still have the problem. Do you think I should shorten it further?

If the problem is with the servo would I be right in guessing the pedal will not be fully returned e.g. The brake light switch might even be activated! If it was a M/C problem the servo would fully return and therefore the pedal. Should that logic not diagnose where the problem lies.
One other piece of info is that the whole setup was fine initially, it's come on with time.
You should only need a marginal gap (when it is hot) - 4mm is way too much gap.

How have you connected your servo to your pedal? - have you used a clevis or a rose joint?
How well did the servo input and the pedal line up?

My guess (and it is a guess) is that your servo input valve is not seating totally, and is allowing atmospheric pressure to activate the servo slightly.
Since you had no problems with your old servo, logic suggests the problem is due to the set up of the new servo, and its connection with the pedal on the input side and the master cylinder on the output side. As you have a huge (4mm) gap to the M/C I doubt this is the problem. So it comes back to the input side of the servo.
Does your brake pedal switch prevent your pedal from coming back further?
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