British Rail Eastern Region - Fault Chart For Brush Type 2 Locomotives (Class 31)Numbers D5520 Onwards
Revised April 1970  -  GM(T)513 - Staff Training School (Diesel Section) Ilford.

More information can be found here Wikipedia - British Rail Class 31   A1A Locomotives Ltd
More Information Regarding Preserved Class 31 Locomotives can be found on the following websites:  Preserved-Diesels