Document Ref 942005-001 Rev 2 Page 3-3
Component Technical Manual TQP-HS for Fuel Dispensers
3.1 Failure Diagnosis
Prior to performing fault diagnosis/search, check the condition of the belt drives.
Following any repair action to the pumping unit, ensure that all the necessary procedures
required by Weights & Measures and applicable safety legislation are correctly followed.
NOTE : Once an O-ring has been removed, it must not be re-used.
Check the normal operation of the pumping unit for one or more of the following problems:-
•No fuel flow (refer to section 3.2.1)
•Reduced fuel flow (refer to section 3.2.2)
•Uneven (pulsing) fuel flow (refer to section 3.2.3)
•Closing of the overflow valve (refer to section 3.2.4)
•Excessive noise (refer to section 3.2.5)