Information

Method of Inspection

Reason for rejection

Types of parking brake mechanism

In this sub-section, it is assumed that the parking brake is applied by a hand lever.

For vehicles with foot-operated parking brakes the “Method of Inspection” detailed will need to be varied for the particular mechanism.

1. Check that the vehicle has a parking brake designed to prevent
. at least two wheels from turning, or
. with a three-wheeled vehicle, at least one wheel from turning.

2. Check the method of operation.

1. The vehicle does not have a parking brake designed to prevent
. at least two wheels from turning
.with a three-wheeled vehicle, at least one wheel from turning.

Pre 1906 vehicles

Vehicles certified by the London Science Museum as being designed before 1 January 1905 and constructed before 31 December 1905 do not require a parking brake.

3. Examine the condition of the brake lever and its location.

2. For vehicles first used on or after 1 January 1968 the parking brake is not capable of being maintained in operation by direct mechanical action only.

3. The brake lever is defective or so located that it cannot be operated satisfactorily.

Hydraulic Parking Brakes

 Hydraulic parking brakes as a sole means of operation are not acceptable on vehicles first used on or after 1 January 1968. However, they may be used to assist the application or release of a mechanical brake.

4. With the brake lever in the "off" position

a. Check the amount of side play in the lever pivot by moving the lever from side to side.

Note: Some vehicles have sideways movement of the parking brake lever , when new. Movement is a reason for rejection only when
. the pawl is moved clear of the ratchet, and
. the brake does not hold in the 'on' position *

b. check the security of the lever and pawl mechanism pivots, their associated mountings and the presence and effectiveness of retaining and locking devices.

Note: Items not possible to check fully from the driver's seat should be checked from beneath the vehicle.
Opening the bonnet to inspect fully the parking brake mechanism might also be necessary.

3. The brake lever is defective or so located that it cannot be operated satisfactorily.

4.
a. side play in the brake lever pivot to the extent that the pawl may inadvertently disengage

b.the lever or pawl mechanism pivots and their associated mountings are insecure or a locking or retaining device is insecure or missing.

5. Without operating the pawl mechanism, apply the parking brake slowly and check the effective operation of the pawl mechanism by listening for definite and regular clicks as the pawl moves over the ratchet teeth.

6. When the brake is fully applied

a. knock the top and each side of the lever and check that the lever stays in the "on" position

check that the lever is not at the end of its working travel and that there is no fouling of adjacent parts

5. The pawl spring is not pushing the pawl positively into the ratchet teeth or the ratchet has broken, or excessively worn, teeth.

6.
a. when knocked, the lever is not held in the "on" position

b. when the brake is fully applied there is no possibility of further travel of the lever because the lever is

. at the end of its working travel on the ratchet, or
. fouling adjacent parts of the vehicle

c. check that the lever is not impeded in its travel.


7. Check the vehicle structure around the mounting of the parking brake and associated mountings for fractures, cracks, corrosion and distortion.

Note: It may be necessary to check the parking brake lever mounting 'prescribed area' from the vehicle underside when it cannot be checked from the inside.

c. the lever is impeded in its travel.

7. 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 30cm of the parking brake mechanism or any associated mounting(s), that is, within a 'prescribed area', see Appendix C.

Issue Date: 10th January 2005