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Test of Suspension

Under bonnet checks

  • Check upper suspension joints
  • Any other suspension parts which can be inspected from beneath the bonnet

Under vehicle checks

Applies to both front and rear suspension

  • No nuts or split pins missing, no components broken or excessively damaged
  • Road springs checked for condition
  • All suspension joints checked for condition
  • Ball joint dust covers are checked for not allowing ingress of dirt etc
  • Shock absorbers should not leak and must be secure (the vehicle will be 'bounced' by the Tester* to check that they damp the springs adequately).
  • Inappropriate modification or repair of suspension components
  • Any drive shaft (except the prop shaft) support bearing excessively worn or coupling gaiter missing or no longer preventing entry of dirt etc.

The suspension is checked for wear by the assistant applying loads in different ways with the wheels jacked  as the Tester observes  from beneath the vehicle. This may include the use of special wheel play detectors in some test stations.

* This item to be removed from the MOT Test subject to legislation being passed.

Note: There are many different suspension systems and types, and the specific nature of any test will depend to a large extent on the system design.


Test of Brakes

Brake efficiency is usually checked on a roller brake tester. In cases where a roller brake tester may not be used (for example on some 4-wheel drive vehicles) it can be necessary to check brake balance and efficiency on a road test, using a portable decelerometer.

Inside the car

  • Electronic parking Brake, warning device should not be indicating a malfunction
  • Electronic stability control 
  • component must not be missing, blatantly damaged or inappropriately repaired or modified
  • ESC wiring should not be excessively damaged
  • ESC warning lamp should be present, working and not indicating a fault
  • ESC Switch should not be insecure or faulty
  • A brake slack adjuster should not be defective or incorrectly installed
  • A brake fluid warning lamp should not be inoperative or illuminated
  • Class (v): Electronic braking system  warning device should not be inoperative or indicating a fault


Anti-lock braking system if present, warning lamp is checked for:

  • Function
  • Sequence of operation


  • Sufficient reserve travel to the footbrake
  • Pedal rubber wear not excessive
  • ABS and ESC parts and associated switch/wiring checked for presence and condition


Parking brake
This could be hand, foot or electronically operated. Check for reserve travel so that it doesn't reach the stops on application. The mountings to be checked for security and corrosion.

The brake lever or control to fail if:

  • missing
  • insecure
  • defective or situated so that it cannot be properly operated
  • any inappropriate repair or alteration

During a decelerometer test, vehicle deviation from a straight course when parking brake applied then this becomes a fail.

Anti-Lock Braking (ABS) and Electronic Stability Control (ESC) Systems

The inspection applies to all systems, original equipment or 'postmarket'. Will be checked for being fitted, illuminating, not indicating fault, ABS to follow proper sequence.
If ABS or ESC system has been intentionally rendered inoperative the whole system, with the exception parts which form part of another component:

  • component damaged, missing, inappropriately repaired or modified
  • wiring damage excess


Warning Lamp

  • Missing
  • Does not function
  • Indicates a fault
  • (ABS) does not follow correct sequence



  • Components missing or excessive damage
  • Wiring excessive damage
  • Inappropriately modified
  • Switch faulty not secure


Under bonnet checks
Master cylinder and servo unit to be checked for leaks with the engine running and the brakes applied
Servo unit to be checked to ensure it is functioning correctly
Visible metal or flexible brake pipes checked for corrosion, condition or leaks

Under vehicle checks

All brake pipes metal and flexible visible beneath the car are checked
Discs and drums (external only) tested for condition and contamination
Caliper securing devices and brake back plates are checked for condition and security
Condition of the brake pads to be checked if visible
The handbrake is operated and the condition of the linkages and/or cables is checked.
On some vehicles there is a brake compensating valve beneath the car which must be inspected for fluid leaks

All components checked for condition, operation and security

Reason for failure:

  • Component inappropriately modified
  • Insecurely mounted
  • Excessively weakened
  • Damaged
  • Locking or retaining device not secure
  • Cable, rod or clevis joint notsecure
  • A load sensing valve, inoperative, seized function impaired or adjusted incorrectly
  • Air brake actuator dust cover not present or not preventing ingress of dirt etc.


Brake performance check
The performance of front and rear brakes and the handbrake are checked for balance and efficiency using specialised equipment.