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ADVISE & IDEASBrake Adjustments

In need of help with brake adjustments? Just follow these step-by-step instructions or contact your nearest branch when in doubt. Our staff will be more than willing to give you some guidance.

(Please note: The same procedure is used in both the Knott & the GSM type brakes)

  • Fit the wheels to the trailer.
  • Ensure that all the wheels are in the air and they can rotate freely. The expander on the brake must not be under tension (if necessary the brake rod can be loosened. Check the actuation of the expander and the cable.
  • Adjust each wheel brake as follows:
    The wheel may only be rotated in the FORWARDS direction during brake set-up. The brake system will not function correctly if the wheels are rotated backwards at any stage of the brake set-up.
    While rotating the wheel turn the Adjuster Bolt (opposite the cable inlet) CLOCKWISE until the wheel can no longer be turned or else rotate with great difficulty.
    Loosen the Adjuster Bolt by turning anti-clockwise (approximately ½ turn) until the wheel rotates freely forwards. Slight grinding noises that do not affect the free running of the wheel are permitted. Do not use any turnbuckles etc fitted on the brake rod to adjust the brakes. Do not use the brake rod itself to adjust the brakes. Fit the brake cables to the compensators as shown.
    Tandem set up viewed from under the trailer. Note the grouping of the brake cables to correctly distribute the brake input forces.
    Single axle set up viewed from under the trailer. Note the use of compensator and nuts to correctly distribute the brake input forces.
    In all cases, all the M8 nuts must be in front of the compensators. Do not fit a nut to the M8 threaded end behind the compensator from sharing the input force evenly between the brakes (violation of 5.2.2.5 above).
  • After all of the brakes have been set, balance the brakes as follows:
    Ensure that the coupler shaft is in the fully open position.
    Adjust the length of the brake rod until the transmission lever touches the back of the coupler shaft (slight play < 3mm is acceptable). Pull up the hand brake lever and check the position of the brake compensators (they should be perpendicular to the brake rod). If necessary, adjust brakes until the compensators are perpendicular to the brake rod when the hand brake lever is pulled. Actuate the hand brake a few times then gently pull the lever further to correctly set up the brakes. Release the hand brake. Spin the wheels forwards and pull up the hand brake. With over-center hand brakes, the braking effect should start when the lever is 10-15mm over center. On ratchet hand brakes, the braking effect should start on the third tooth.
  • Lower the trailer and take for a test drive.

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