SCG Classic Car Troubleshooting Checklist - Drum Brakes

This is a quick-reference guide for troubleshooting common classic car problems, in this case the conventional hydraulic drum brake system. Follow the steps and see how easy it will be to find the cause of your symptom.

Pedal goes to the floorboard

1. Shoes out of adjustment
2. Brake fluid level low
3. Leaking line or cylinder
4. Air in line or cylinder
5. Defective master cylinder

One brake drags

1. Incorrect shoe adjustment
2. Clogged brake line
3. Sluggish wheel cylinder piston
4. Weak brake shoe return spring
5. Loose wheel bearing
6. Brake shoe binding on backing plate
7. Out-of-round drum

All brakes drag

1. Insufficient play in master cylinder push rod
2. Master cylinder relief port plugged
3. Lubricating oil in system instead of hydraulic fluid
4. Master cylinder piston sticking

Car pulls to one side

1. Brake fluid or grease on lining
2. Sluggish wheel cylinder piston
3. Weak retracting spring
4. Loose wheel bearing
5. Wrong brake lining
6. Drum out-of-round

Soft pedal

1. Air in system
2. Improper anchor adjustment
3. Improper linings
4. Thin drums