Results 1 to 4 of 4

Thread: Unique problem need help! Brake pedal stiff and not working at all.

  1. #1
    Guest
    Join Date
    Mar 2024
    Location
    Kent
    Posts
    5
    Rides
    0

    Unique problem need help! Brake pedal stiff and not working at all.

    Hi all I have an S14a with R33 front calipers and I genuinely cant understand what's happening and YES I have searched the forum first.

    When the car is moving the brake pedal is completely stiff, apart from a little play it does not go down at all and the brakes do not work at all. When the car comes to a stop the pedal then goes all the way to the floor with minimal resistance and when I let go it comes back up a little slow. The rpms of the engine do not affect the problem at all

    There are NO leaks and NO pinched lines, all 4 calipers bled easily and I inspected all the brake lines and its all dry (it has new braided lines).

    The vacuum lines to the booster have the odd extremely minor crack at the end of them but its not enough to cause this big of a problem, the lines as a whole are flawless.

    The check valve is the correct way around and functions correctly.

    I HAVE REPLACED THE FOLLOWING:
    Brake Booster (used, off another car)
    Brake Master Cylinder (brand new gktech BM57)

    despite all this my problem is still here! Have some pity on a 17 year old and help out pleaseee

  2. #2
    Member WTFIA's Avatar
    Join Date
    Apr 2011
    Location
    The Shire
    Posts
    823
    Rides
    0
    You definitely have the pipes on the BMC the right way around front to back?

  3. #3
    Guest
    Join Date
    Mar 2024
    Location
    Kent
    Posts
    5
    Rides
    0
    SOLVED (temporarily):

    I read somewhere that the ABS module can cause a stiff pedal that dosent move. I then disconnected the connectors to the ABS module and the ABS fuse in the interior fuse box and the problem has gone! The pedal does still go quite far down but it just needs bleeding.

    My theory is that the ABS module was malfunctioning causing it to think that the wheels were constantly locked up and therefore not allowing hydraulic pressure to reach the calipers. Im assuming the pedal starts working when the car stops because it detects that the cars no longer moving hence ABS is not required and it allows flow of fluid to the calipers?

    A porper fix would be the module but for now I am happy running without ABS.

  4. #4
    Member
    Join Date
    Jul 2006
    Location
    Dublin, Ireland
    Posts
    2,104
    Rides
    0
    Quote Originally Posted by akina_touge06 View Post
    SOLVED (temporarily):

    I read somewhere that the ABS module can cause a stiff pedal that dosent move. I then disconnected the connectors to the ABS module and the ABS fuse in the interior fuse box and the problem has gone! The pedal does still go quite far down but it just needs bleeding.

    My theory is that the ABS module was malfunctioning causing it to think that the wheels were constantly locked up and therefore not allowing hydraulic pressure to reach the calipers. Im assuming the pedal starts working when the car stops because it detects that the cars no longer moving hence ABS is not required and it allows flow of fluid to the calipers?

    A porper fix would be the module but for now I am happy running without ABS.
    The ABS controller is in the boot on the left hand side. You could swap that out with someones to eliminate it from the equation.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •