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Lamps Positions	Anti Locking Brake Systems	Exhaust System
Headlamps	Mechanical Brake components	Exhaust Emissions - Spark Ignition - General
Brake Lights	Hydraulic, Air and Vacuum Systems	General Condition of the Vehicle
Reflectors	Brake Performance (Roller Brake Test)	Mirrors
Indicators	Method of Calculating Brake Performance	Fuel System
Headlamp Aim	Ministry and Manufacturer's Plates	Registration Plates and VIN Details
Steering	Tyres	Exhaust Emmisions
Parking Brake	Tyre Size, Ply Rating and Load Index Tables	Structural Integrity and Corrosion
Brake Efficiency Table	Seat Belts	Test Equipment
Hand Operated Brake Control Valves	Windscreens/Drivers View of the road	Vehicle Identification Number Location
Exhaust Emissions/Service Brake Control	Audible Warning (Horn)	Identifying Code Locations

3.8 Method of Calculating Brake Performance

8.1 Brake Efficiency

Total up the braking effort recorded from all the wheels of the vehicle when the service brake is applied. Total up the braking effort recorded from the appropriate wheels when the parking brake is applied. Calculate the service brake and the parking brake percentage efficiencies by following the procedure detailed below according to the class of vehicle tested

Class III and IV Vehicles

Determine the weight of the vehicle from the current Brake Data Chart (the data includes an element of 140kg or 300lbs for the weight of the driver, fuel, tools, etc) Calculate the service brake percentage efficiency by dividing the total brake effort achieved when the service brake is applied by the vehicle weight and then multiplying the result by 100,ie Total brake effort x 100 = % Efficiency Vehicle Weight Calculate the parking brake percentage efficiency by dividing the total brake effort achieved when the parking brake is applied by the vehicle weight and then multiplying the result by 100, as above.

Class VII Vehicles

Obtain the vehicle Design Gross Weight (DGW) from the Department of Transport plate (commonly called 'Ministry Plate') fitted to the vehicle. If a Ministry plate is not fitted to the vehicle then obtain the DGW from the manufacturers plate fitted to the vehicle (see notes 1 and 2 on page 27) Calculate the service brake percentage efficiency by dividing the total brake effort achieved when the service brake is applied by the vehicle DGW and then multiplying the result by 100.

ie Total brake effort x 100 = % Efficiency

DGW Calculate the parking brake percentage efficiency by dividing the total brake effort achieved when the parking brake is applied by the vehicle DGW and then multiplying the result by 100, as above. Note: Plate Brake Test Only Vehicles with a presented weight of 2000kg or more must be tested to the above criteria. On vehicles with a presented weight of less than 2000kg, the brake efficiency must be calculated using a nominal DGW figure of 2600kg.

ie Total Brake Effort x 100 = % Efficiency

2600

8.2 Brake Out-of-Balance

The out of balance of the braking effort on the front steered wheels when the service brake is applied is obtained by comparing the brake efforts at each front wheel when they are tested simultaneously (see sub section3.7.2, page 19). Carry out the following calculation to determine the percentage imbalance:

(Higher brake effort - Lower brake effort) x 100 =% imbalance

Higher brake effort

Brake Efficiency

Total up the braking effort recorded from all the wheels of the vehicle when the service brake is applied. Total up the braking effort recorded from the appropriate wheels when the parking brake is applied. Calculate the service brake and parking brake percentage efficiencies by following the procedure detailed below according to the class of vehicle tested.

Class III and IV Vehicles

Determine the weight of the vehicle from the current Brake Data Chart (the data includes an element of 140 kg or 300 lbs for the weight of the driver, fuel, tools, etc.) Calculate the service brake percentage efficiency by dividing the total brake effort achieved when the service brake is applied by the vehicle weight and then multiplying the result by 100,

ie Total brake effort x 100 = % Efficiency
Vehicle Weight Calculate the parking brake percentage efficiency by dividing the total brake effort achieved when the parking brake is applied by the vehicle weight and then multiplying the result by 100, as above.

Class VII Vehicles

Obtain the vehicle Design Gross Weight (DGW) from the Department of Transport plate (commonly called 'Ministry' plate) fitted to the vehicle. If a Ministry plate is not fitted to the vehicle then obtain the DGW from the manufacturer's plate fitted to the vehicle (see Notes 1 and Z on page 27) Calculate the service brake percentage efficiency by dividing the total brake effort achieved when the service brake is applied by the vehicle DGW and then multiplying the result by 100.

ie Total brake effort x 100 = % Efficiency
DGW Calculate the parking brake percentage efficiency by dividing the total brake effort achieved when the parking brake is applied by the vehicle DGW and then multiplying the result by 100, as above.

Note: Plate Brake Test Only Vehicles with a presented weight of 2000Kg or more must be tested to the above criteria. On vehicles with a presented weight of less than 2000Kg, the brake efficiency must be calculated using a nominal DGW figure of 2600Kg.

ie Total brake effort x 100 = % Efficiency
2600

8.2 Brake Out-of-Balance

The out of balance of the braking effort on the front steered wheels when the service brake is applied is obtained by compairing the brake efforts at each front wheel when they are tested simultaneously (see sub section 3.7.2) Carry out the following calculation to determine the percentage imbalance:

(Higher brake effort - Lower brake effort) x 100 = % imbalance
Higher brake effort

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Reproduced from the MOT Inspection Manual by kind permission of THE VEHICLE INSPECTORATE.