Skip to main content
Department for Infrastructure Department for Infrastructure An Roinn Bonneagair Depairtment fur Infrastructure

Main navigation

  • Home
  • Topics
  • Publications
  • Consultations
  • Contact

Translation help

Translate this page

Select a language

  • Arabic — عربي
  • Chinese (Simplified) — 中文简体
  • Chinese (Traditional) — 中文繁體
  • Dutch — Nederlands
  • Filipino — Filipino
  • French — Français
  • German — Deutsch
  • Hungarian — Magyar
  • Irish — Gaeilge
  • Italian — Italiano
  • Latvian — Latviešu
  • Lithuanian — Lietuvių kalba
  • Polish — Polski
  • Portuguese — Português
  • Romanian — Română
  • Russian — Русский
  • Slovak — Slovenčina
  • Spanish — Español
  • Ukrainian — Українська
  • Service Brake Control

    Topics:
    • Road users, 
    • Driver & Vehicle Agency

    Form Number: DVT 917
    Issue: 6
    Origin: DVT
    Review: Jan 2028

    Information 

    This inspection applies to all vehicles. 

    The Following Information Only Applies To Section ‘A’ Only 

    Vehicles with smooth brake pedal pad which from manufacture did not incorporate grooves 

    or the fitting of an anti-slip material should not be subject to refusal. 

    The provision of a pedal rubber which is itself an anti-slip material is not regarded as a 

    reason for rejection if the design pattern is worn smooth. 

    Three wheeled mopeds, light quadricycles and motorcycle based tricycles and quadricycles 

    may have handlebar mounted brake controls. These controls and their mountings should be 

    examined. 

    The Following Information Only Applies To Section ‘E’ Only 

    1. This inspection applies to vehicles registered on or after 1 October 1937. 

    2. A vehicle of 3050 kg or less unladen, with 

    • a reservoir coupled direct to the induction manifold, or 

    • a reservoir integral in a servo unit

     Is not necessarily required to be fitted with a warning device.

    3. A defective audible warning device is not a reason for rejection if fitted in addition to an operational visual device. 

    4. For vehicles first used on or after 1 April 1983, a defective visual warning device is not a reason for rejection if fitted in addition to an operational audible device. 

    Method Of Inspection 

    A. All Types Of Braking System 

    1. Check 

    • The condition of the brake pedal and brake actuating linkage (e.g., to remote master cylinders). 

    • The anti-slip face on the pedal pad. 

    • The security of the pedal pad to the pedal and the pedal to operating lever. 

    • The condition of the pedal bearing or pivot. 

    • For chafed rods or levers. 

    • For corroded, frayed or knotted cables. 

    • For any corroded or damaged rod, lever or linkage.  Wear in eyes of relay levers, clevis joints, stationary pins or pivots. 

    • For abnormal movement of levers, indicating maladjustment or excessive wear. 

    2. Examine the vehicle structure near actuating linkage and mounting points for fractures, cracks, corrosion and distortion. 

    3. On vehicles used on or after 1st Jan 1968, check that a single brake control applies to all wheels (this may need to be substantiated during the brake test). An exception is three wheeled mopeds, light quadricycles and motorcycle based tricycles and quadricycles which may have two separate service brake systems each having a separate means of operation. 

    4. Depress the pedal and check for fouling on parts of the vehicle. 

    5. Depress the pedal fully and check the position of the pad relative to the floor. 

    6. Check the service brake control for any inappropriate repair or modification. 

    B. Hydraulic Systems (Including Servo Assisted) 

    1. Fully depress the pedal twice, first slowly and then rapidly each time to a point where sustained pressure can be held.  Check for creep and sponginess. 

    2. If a vacuum servo is fitted, then with the engine off, totally deplete the stored vacuum by repeatedly applying the service brake.  Fully apply the brake and hold at a constant pressure.  Note whether the pedal can be felt to travel further when the engine is started. 

    C. Vehicles with High Servo Boost 

    Note:  This inspection only applies to a diesel engined vehicle where pedal creep had been detected when pressurising the brakes with the engine running. 

    1. Where possible check the brake fluid level in the reservoir then pump the brake pedal several times and check that the fluid level in the reservoir is unchanged. 

    Note: Under no circumstances must the reservoir cap be removed. 

    2. With the vacuum depleted ensure the pedal is not spongy or does not creep. 

    3. With servo assistance fully depress the pedal. 

    D. Full Power Hydraulic Braking Systems 

    Note:  On some vehicles the low vacuum warning light will illuminate as soon as the ignition is switch on. In these circumstances it is not a reason for rejection unless the warning light stays on after the engine has been started. 

    1. Check that a warning device is fitted. 

    2. Check whether a warning device fitted is audible or visible to driver. 

    3. With the engine switched off, repeatedly apply the service brake until the warning device operates.  Check that at least two further applications of the brakes are available.  In case of doubt the availability of two further applications can be established by trying to move the vehicle forward while the foot brake is applied. 

    Note:   Hydraulic braking systems operate quietly, it is therefore normally necessary to try and move the vehicle to verify that the brakes are applied. 

    E. Air and Vacuum Systems (Including ‘Over Hydraulic’) 

    1. Check that a visual warning device or, as an alternative for vehicles first used on or after 1 April 1983, an audible warning device is:

    • Fitted, 

    • Working correctly. 

    2. Check that any visual warning device is: 

    • Visible from the driving seat, 

    • Illuminated, or otherwise visible from the driving seat in darkness. 

    3. For systems fitted with a pressure or vacuum gauge, with the reservoir at a maximum pressure or vacuum, note the reading on the gauge and then fully depress the pedal. Keep the pedal depressed and watch the gauge reading. 

    Note:   All vehicles must also be checked for pressure or vacuum leaks during the under vehicle inspection of the brake system. 

    4. Check that the operation of any air or vacuum-powered system (e.g. wipers, etc does not adversely affect the operation of the braking system). 

    5. By applying the service brake repeatedly gradually empty the braking system, and

    a. if a gauge is fitted, note that: 

    • The reading on the gauge falls steadily each time the brake pedal is depressed, and 

    • When the gauge needle has reached the ‘warning mark’, there is still enough pressure or vacuum in the system to allow the brake to be applied at least twice more with pressure or vacuum assistance. 

    Note: 

    Pressure gauge 

    If pressure gauge has no warning mark, use 45 psi (3.1 kg/sq. cm or 3 bar) as a reference. 

    Vacuum gauge 

    If the vacuum gauge has no warning mark, use 25 to 30 cm as a reference. 

    b.  If a warning light or other device is fitted, check that, after the warning has operated, there is still enough pressure or vacuum in the system to allow the brake to be applied at least twice more with pressure or vacuum assistance. 

    6. Completely empty the reservoir by repeatedly pressing the service brake pedal.  Start the engine and if diesel run it at just below governed speed or 2000 rpm if petrol.  Note the time it takes for the warning device to stop operating. 

    Reason For Rejection 

    A. All Types of Braking System 

      Reason For Rejection Deficiency Category
    1aThe pedal or actuating linkage fractured, excessively corroded or functionally incomplete.               MAJOR
     bThe pedal or actuating linkage not releasing correctly MINOR
     cPedal or hand lever pivot too tight MAJOR
     dThe anti-slip provision on the brake pedal pad is missing, loose or worn smooth. MAJOR
     eA pedal pad or operating lever not secured to the pedal. MAJOR
     fExcessive side movement of the pedal at right angles to its normal movement indicating a badly worn pedal bearing pivot. MAJOR
     gA brake rod or lever reduced in thickness by more than 1/3rd. MAJOR
     hA brake cable corroded, knotted or with wires broken so that it is weakened significantly. MAJOR
     iSerious weakening of any part due to excessive wear, corrosion or damage. MAJOR
     jAbnormal movement of any part due to excessive wear.MAJOR
      Handlebar mounted control 
     kInsecureMAJOR
     lAttachment screw loose or missing MAJOR
     mExcessively worn control leverMAJOR
     nCracked or fractured MAJOR
     oHas inadequate reserve travel MAJOR
     pInoperative or so damaged, positioned, bent or shortened that the brake cannot be readily applied MAJOR
     qWhich cannot be applied and released smoothly MAJOR
     rDeliberate modified so the original strength is seriously reduced MAJOR
     sExcessively corroded MAJOR
     tInadequately repaired MAJOR
    2 Deliberate modification which significantly reduces the original strength, excessive corrosion, severe distortion, a fracture of an inadequate repair of a load bearing member, its supporting structure or supporting panelling within 30 cm of an actuating linkage mounting point, that is, within a ‘prescribed area’ see Appendix A.MAJOR
    3 On vehicles first used on or after 1st Jan 1968 a brake is not applied to all wheels. MAJOR
    4 The pedal is fouling parts of the vehicle so that free movement of the pedal is obstructed.MAJOR
    5 

    When the pedal is fully depressed, there is not enough reserve pedal movement. 

    Note:   This does not apply to power operated braking systems, provided the foot valve is fully open before the pedal is fully depressed. 

    MAJOR
    6 A service brake control inappropriately repaired or modified. MAJOR

    B. Hydraulic System (Including Servo Assisted) 

      Reason For Rejection Deficiency Category
    1aThe pedal tends to creep down while the pedal is held under pressure. MAJOR
     bSponginess indicating air in the hydraulic system. MAJOR
    2 No dip can be felt when the engine is started, indicating vacuum assistance is not working satisfactorily. MAJOR

    C. Vehicles With High Servo Boost 

     Reason For Rejection Deficiency Category
    1After several applications of the brake pedal the fluid level in the reservoir has decreased. MAJOR
    2With the vacuum depleted the pedal is spongy or creeps. MAJOR
    3With servo assistance the pedal creeps down and touches the floor DANGEROUS

    D. Full Power Hydraulic Braking System 

      Reason For Rejection Deficiency Category
    1 No warning device fitted. MAJOR
    2aA warning device not visible (or audible) to the driver. MAJOR
     bA visual warning device not readily visible to the driver in darkness.MAJOR
    3aA warning device not working correctly. MAJOR
     bInsufficient reserve pressure to give at least two further applications of the brakes after the warning device has operated. MAJOR

    E. Air and Vacuum System (Including ‘Over Hydraulic’) 

      Reason For Rejection Deficiency Category
    1 A mandatory warning device: 
     Anot fitted or  MAJOR
     Bnot working correctly. MAJOR
    2 A visual warning device: 
     ANot visible from the driving seat. MAJOR
     BNot illuminated, or its function not visible from the driving seat in darkness. MAJOR
    3 The gauge reading drops whilst the pedal is kept depressed, indicating a leak in the brake system. MAJOR
    4 The repeated operation of any ancillary air or vacuum powered system completely depleted the stored air or vacuum for the braking system. MAJOR
    5 Insufficient pressure/vacuum assistance for less than:    
     Afour brake applications after the warning device has operated (or gauge shows an unsafe reading) MAJOR
     Btwo brake applications after warning device has operated (or gauge shows an unsafe reading). DANGEROUS
    6 

    The time between starting the engine and the warning device ceasing to operate, or the gauge showing a safe reading indicates that build-up of pressure/vacuum is too slow.

     For example:   

    • More than 3 minutes for pressure systems. 

    • 1 minute for vacuum systems. 

    MAJOR
    7 External damage likely to affect the function of the braking system MAJOR

    Related content

    • Appendix A - Structural integrity and corrosion
    • Approved Tachograph Centre Special Notices
    • Body condition
    • Brakes - Anti-lock braking and electronic control system
    • Brakes - Brake performance
    • Brakes - Hand brake control valves
    • Brakes - Mechanical brake components
    • Brakes - Parking brake control
    • Braking Systems and Additional Braking Devices
    • CPC Information For Training Providers
    • Diesel particulate filters - guidance
    • Disabled driver controls
    • Doors
    • Driver & Vehicle Agency Activity Statistics
    • Driver and Vehicle Agency Monthly Tests Conducted Statistics
    • Drivers View Of The Road
    • Driving controls
    • DVA Compliance and Roadside Enforcement Privacy Notice
    • DVA Driver & Vehicle Testing Privacy Notice
    • DVA Driver Licensing Privacy Notice
    • DVA Driving Theory Test Privacy Notice
    • DVA Graduated Driver Licensing Privacy Notice
    • DVA Passenger Transport Licensing Division Privacy Notice
    • Electrical wiring and equipment
    • Emission control system
    • Engine and transmission mountings
    • Exhaust System
    • Front And Rear Position Lamps, Registration Plate Lamps, Front & Rear Fog Lamp, Reversing Lamp, Daytime Running Lamps, End Outline And Side Marker Lamps
    • Fuel System
    • General Condition Of Vehicle
    • Graduated Driver Licensing – FAQs
    • Guides for Bus Service Operators
    • Headlamps
    • Headlamps Aim
    • Horn
    • Lamps - Direction indicators and hazard warning lamps
    • Light Vehicle Inspection Manual - DVA - HTML
    • Load Security
    • Manufacturers Plates
    • Mirrors
    • Oil Leaks
    • Passenger Transport Licensing Division – Security Policy
    • Plates - Registration Plates
    • Policy on the Licensing of Ex-Offenders
    • Power Assisted Steering
    • Rear Reflectors
    • Recommended Topside Inspection Routine
    • Recommended Underside Inspection Routine
    • Roadwheels
    • Seat Belts And Supplementary Restraint Systems (SRS)
    Share this page Share on Facebook (external link opens in a new window / tab) Share on X (external link opens in a new window / tab) Share by email (external link opens in a new window / tab)

    Department footer links

    • Crown copyright
    • Terms and Conditions
    • Privacy
    • Cookies
    • Accessibility
    • The Northern Ireland Executive
    • The Executive Office
    • Department of Agriculture, Environment and Rural Affairs
    • Department for Communities
    • Department for Education
    • Department for the Economy
    • Department of Finance
    • Department for Infrastructure
    • Department for Health
    • Department of Justice
    • nidirect.gov.uk — the official government website for Northern Ireland citizens