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
  • Braking Systems and Additional Braking Devices

    Topics:
    • Road users, 
    • Driver & Vehicle Agency

    Form Number: DVT 934
    Issue: 6
    Origin: DVT
    Review: Jan 2028

    Information 

    This inspection applies to all vehicles. 

    This inspection applies to all types of braking system. 

    Repairs to the pressure lines of hydraulic brake systems are unacceptable unless suitable connectors are used. Compression joints of a type using separate ferrules are not suitable. 

    A missing brake pipe clip is not necessarily a Reason for Rejection provided the brake pipe remains adequately supported. 

    Certain alloy components may have a white surface deposit which is not to be regarded as ‘excessive corrosion’. 

    Hydraulic brake fluid level checks are confined to transparent reservoirs or where an indicator is fitted. Reservoir caps should not be removed. 

    A brake fluid warning lamp may be a combined lamp for other aspects, such as worn brake pads or parking brake applied. 

    Additional Braking Devices are fitted to some vehicles to provide additional braking (e.g. electric or fluid retarders or exhaust brakes). 

    Method of Inspection 

    A. All Braking Systems 

    1. Check for leaks in any part of the braking system, with and without the brakes being applied. 

    2. Check all components for security, condition and operation. 

    3. Check all braking system components for any inappropriate repair or modification. 

    Note:   For vehicles fitted with vacuum servo or power operated brakes, the engine must be idling during these inspections. 

    Note:   On some vehicles, a complete inspection of the service brake system requires the bonnet to be opened, therefore this inspection would have been done at a previous stage. 

    B. Brake Pipes and Flexible Hoses 

    1. Check that rigid brake pipes are securely held and not free to vibrate. 

    2. Check all accessible rigid brake pipes for: 

    • Fouling by a moving part, 

    • Kinks, 

    • Chafing, corrosion and damage, 

    Note:   To assess correctly the condition of corroded metal pipes, surface dirt might have to be removed.  This might require light scraping with the Corrosion Assessment Tool ‘spade end’. Care must be taken not to damage any protective coating. 

    3. Examine flexible hoses for signs of weakness. 

    4. Examine all flexible hoses for: 

    • Room to move as necessary without fouling any part of vehicle, 

    • Kinks, 

    • Stretching or twisting, 

    • Chafing, damage or deterioration, 

    Note:  A hose should be rejected for cracking or chafing only if that is severe enough to expose the reinforcement. 

    • Exposure to excessive heat. 

    • Condition of ferrules 

    C. Servos And Master Cylinders 

    1. Check servos for: 

    a. Presence 

    b. vacuum pipe deteriorated, kinked, split, collapsed or excessively chafed 

    c. leaks. 

    2. Where an adjustment indicating rod is provided, check if brake adjustment is necessary. 

    3.  Examine the condition of chassis or body structure and panelling around the master cylinder or combined master cylinder / servo mounting. 

    D. Reservoirs (Air/Vacuum) (Including Accumulators, Pressure And Vacuum Vessels) 

    1. Check reservoir mountings and securing straps: 

    a. are free from cracks, fractures and excessive corrosion 

    b. do not chafe the reservoir or other fittings. 

    2. Check that the reservoir capacity is not unduly reduced by deformation. 

    E. Valves 

    1. Check for excessive discharge of oil from pedal exhaust valve, unloader valve and/or governor valve, quick-released valve, etc. 

    2. Check that a load sensing valve is present and connected, if it is a standard item. 

    3. Check the condition and operation of the load sensing valve where fitted, including any operating linkage. 

    F. Pumps And Compressors 

    1. Check the security of the vacuum pump or air compressor. 

    2. Check the condition of the vacuum pump or air compressor drive system. 

    G. Hydraulic Systems 

    1. Check fluid reservoirs for: 

    a. presence of cap 

    b. fluid level. 

    2. Check that the brake fluid warning lamp is not illuminated or defective. 

    3. Check where possible brake fluid for contamination 

    H.  Air Systems 

    1. Check each brake cylinder/actuator for travel of operating pistons/diaphragms and mechanisms. 

    2. Check the presence and condition of dust covers on brake actuators. 

    I.  Additional Braking Devices 

    1. Examine the device, its contacts and other components for condition and security. 

    2. Check for adequate clearance between the device and other components. 

    3. Check for presence and condition of heat shields if required. 

    4. Check for signs of overheating of a component or its surroundings. 

    5. Check for condition, position and security of electrical wiring and switchgear. 

    6. Check for exhaust gas or oil leaks. 

    J.  Electronic Braking Systems 

    1. On vehicles fitted with an electronic braking system, check that a warning device: 

    a. is fitted 

    b. is operative 

    c. does not indicate a fault

    Reason For Rejection 

    A. All Braking Systems 

      Reason For RejectionDeficiency Category
    1 A leak in any part of a braking system.DANGEROUS
    2 A braking system component: 
     ainsecurely mountedMAJOR
     bexcessively weakened by corrosionMAJOR
     cdamaged to the extent that its function is impairedDANGEROUS
     dinoperativeDANGEROUS
     eretaining or locking device missing or insecure.MAJOR
    3 A braking system component inappropriately repaired or modified.MAJOR

    B. Brake Pipes And Flexible Hoses 

      Reason For RejectionDeficiency Category
    1 A rigid brake pipe inadequately clipped or otherwise supported.MINOR 
    2 A rigid brake pipe likely to become detached or damaged MAJOR
    3 A rigid brake pipe: 
     aFouled by moving parts, MAJOR
     bKinked, MAJOR
     c

    Excessively chafed, corroded or damaged or excessively built up with rust. 

    Note:    Chafing, corrosion, or damage to, a rigid brake pipe so that its wall thickness is reduced by 1/3rd (e.g., approximately 0.25 mm for typical hydraulic brake pipe) is a reason for rejection. 

    MAJOR
     d

    Inadequately repaired or with unsuitable joint fittings. 

    Note:    Repairs to the pressure lines of hydraulic brake systems are unacceptable unless suitable connectors are used. Compression joints of a type using separate ferrules are not suitable. 

    MAJOR
    4 A flexible hose bulged. MAJOR
    5 A flexible hose: 
     aHas insufficient room to move, resulting in fouling on any part, MAJOR
     bSlightly damaged or slightly twisted MINOR
     cKinked, MAJOR
     dStretched or twisted,MAJOR
     eExcessively chafed or deteriorated, MAJOR
     fExposed to excessive heat. MAJOR
     gBrake hose ferrules excessively corroded DANGEROUS
     hBrake hose damaged and likely to fail MAJOR

    C. Servos And Master Cylinders   

      Reason For RejectionDeficiency Category
    1 A servo: 
     aMissing when fitted as standard MAJOR
     bInsecurely mounted, MAJOR
     cExcessively weakened by corrosion, MAJOR
     dDamaged to the extent that its function is impaired, MAJOR
     eVacuum pipe deteriorated, kinked, split, collapsed, excessively chafed or disconnected,MAJOR
     fLeaking. MAJOR
    2 Adjustment indicating rod shows brake adjustment is necessary or does not move freely. MAJOR
    3 Deliberate modification which significantly reduces the original strength, excessive corrosion, severe distortion, a fracture or an inadequate repair of a load bearing member or its supporting structure or supporting panelling within 30 cm of the master cylinder/servo mounting, that is, within a ‘prescribed area’, see Appendix A.MAJOR

    D. Reservoirs (Air/Vacuum) (Including Accumulators, Pressure And Vacuum Vessels) 

      Reason For RejectionDeficiency Category
    1 Reservoir mountings and securing straps: 
     aCracked, fractured or excessively corrodedMAJOR
     bChafing reservoir or other fittings.MAJOR
    2 A significant reduction in reservoir capacity as a result of deformation. MAJOR
    3 Reservoir:  
     aHas minor damage or corrosionMINOR
     bHeavily damaged, heavily corroded or leaking. MAJOR
    4 Drain device on an air brake system: 
     aOperation affectedMINOR
     bInoperativeMAJOR
    5 Reservoir insecure or inadequately mounted MAJOR

    E. Valves 

      Reason For RejectionDeficiency Category
    1 Excessive discharge of oil from a compressor or brake valve. MINOR
    2 Damaged or excessive air leak MAJOR
    3 Leaking such that brake functionality is affected. DANGEROUS
    4 Valve insecure or inadequately mounted.MAJOR
    5 Hydraulic Fluid:  
     aLeak from a brake valveMAJOR 
     b

    Leak from a brake valve such that brake functionality is 

    affected. 

    DANGEROUS 
    6 A load sensing valve or its operating linkage obviously:  
     aremoved where it is known to be fitted as standard DANGEROUS
     bseized or inoperative and ABS functioning MINOR
     cseized or inoperative and ABS not fitted or inoperative functioning MAJOR
     ddefective so that its function is impaired, DANGEROUS
     eincorrectly adjusted.MAJOR

      F. Pumps and Compressors 

     Reason For RejectionDeficiency Category
    1A pump or compressor insecure. MAJOR
    2

    A pump or compressor drive system missing or defective. 

    Note:   If more than one drive belt is fitted as standard then it is not a  reason for rejection unless all belts are missing. 

    MAJOR

    G. Hydraulic Systems 

      Reason For RejectionDeficiency Category
    1 A fluid reservoir:  
     acap missing MAJOR
     blevel below the minimum indication when this is shown.MINOR 
     clevel significantly below the minimum indication when this is shown.MAJOR
     dlevel so low that it is not visible DANGEROUS
    2 A brake fluid warning lamp is illuminated or inoperative. MINOR
    3 Brake fluid contaminated MAJOR

    H.  Air Systems 

      Reason For RejectionDeficiency Category
    1 A brake cylinder/actuator: 
     ahas excessive travel of the operating mechanism indicating need for adjustment. MAJOR
     binoperative MAJOR
    2 A brake actuator dust cover missing, insecure or damaged to the extent that it no longer prevents the ingress of dirt etc.MAJOR
    3 Air or antifreeze leaking, but not affecting the function of the systemMINOR 

    I.  Additional Braking Devices 

     Reason For RejectionDeficiency Category
    1A device, contacts or mountings insecure, but unlikely to detach.MINOR
    2A device, contacts or component damaged, contaminated, insecure or obviously inoperative. MAJOR
    3Inadequate clearance between the device and other components. MAJOR
    4A heat shield missing or damaged. MAJOR
    5Overheating of a component or its surroundings. MAJOR
    6Wiring in poor condition, badly positioned or not secure.MAJOR 
    7Exhaust gas or oil leaking from the device.MAJOR 

    J. Electronic Braking Systems   

      Reason For RejectionDeficiency Category
    1 The warning device: 
     ais missingMAJOR 
     binoperativeMAJOR
     cindicates a faultMAJOR

    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
    • 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)
    • Seats
    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