Fault diagnosis

Fault diagnosis

(a) 'Spongy' pedal

1. Leak in the system
2. Worn master cylinder
3. Leaking wheel cylinders
4. Air in the system
5. Gaps between shoes and underside of linings

(b) Excessive pedal movement

1. Check 1 and 4 in (a)
2. Excessive lining wear
3. Very low fluid level in supply reservoir
4. Too much free movement of pedal

(c) Brakes grab or pull to one side

1. Brake backplate loose
2. Scored, cracked or distorted drum
3. High spots on drum
4. Unbalanced shoe adjustment
5. Wet or oily linings
6. Worn or loose spring fixings
7. Front suspension or rear suspension anchorages loose
8. Worn steering connections
9. Mixed linings of different grades
10. Uneven tyre pressure

11 Broken shoe return springs

12 Seized handbrake cable