Road/Roller Testing (page 2 of 3)

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Manual gearbox: Clutch takes up the drive smoothly, without slip or judder.  

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Gear changing is smooth, and there are no abnormal noises or vibrations from the gearbox.  

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The engine power output is satisfactory, acceleration is smooth and accelerator pedal operation is not stiff or 
heavy, and engine speed returns to idle correctly.  

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There is no excessive or abnormally colored smoke from the engine under normal driving, heavy load or overrun 
conditions.  

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Steering operation is smooth, accurate, not excessively heavy or with excessive free play or vibration. Does not 
pull to one side and self centres smoothly after cornering.  

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All instruments register the correct readings and operate correctly.  

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Switches and controls operate smoothly and positively, warning or indicator lights operate correctly and the 
direction indicator control self cancels when the steering is returned to the straight ahead position.  

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Heating and ventilation systems work correctly and effectively.  

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Brakes operate efficiently.  

Brake Testing  

Avoid brake testing on busy roads where it can cause inconvenience or danger to other road users.  
 

 
Test the brakes at several speeds within the normal operating range using both light and heavy pedal pressure. Note any 
tendency to snatch, pull or drag, and any undue delay in application or release.  
 
Allow the vehicle to coast and note any tendency to pull to one side, or evidence that the brakes are binding.  
 
After stopping the vehicle (not immediately after a period of heavy braking), carefully check the brake temperature. A disc 
which feels appreciably hotter than the others, could indicate that the pads on that disc are binding.  
 
After completion of the test, check for:  
 

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Oil, coolant, hydraulic, air and fuel leaks.  

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Abnormal temperature of any moving components or assemblies, e.g. wheel hubs, transmission etc., which might 
indicate over tightness or lack of lubrication.  

Rolling Road Testing  

 
Four Wheel Rolling Road  
 

 
Provided that front and rear rollers are rotating at identical speeds and that normal workshop safety standards are 
applied, there is no speed restriction during testing except any that may apply to the tires.  
 
Ensure that the parking brake is released prior to engaging roller driving mechanism.  
 
Two Wheel Rolling Road  
 

   CAUTION: Brake testing which includes heavy brake applications should not be carried out with new 

brake pads/discs until the components have bedded-in. New brake friction components will not reach full 
efficiency until the bedding-in process is complete. Note that when new parking brake shoes or rear brake discs 
have been fitted, it is essential that the 'bedding-in' procedure given in Section 206-05 - Parking Brake Removal 
and Installation is carried out.

   CAUTION: On no account should an attempt be made to carry out any form of brake testing on either a 

two or four wheel rolling road. As it will be necessary to disconnect both front and rear propeller shafts from 
their respective final drive units prior to carrying out rolling road testing, rolling roads may only be used to 
check for abnormal noises or vibration from the final drive units, brake and suspension assemblies. 

   WARNING: Do not operate the footbrake or parking brake whilst the rollers are driving the road wheels. 

Ensure that once disconnected, propeller shafts are properly secured and clear of all moving components.