1) Improper application and improper cleaning of sealant.|2) Excess sealant was applied during the assembly operation and the excess squeezed out sealant was not completely removed after the completion of assembly. |3) In the earlier method the fillet formation during the squeeze out was not uniform therefore the assembly operator applied excess sealant and missed to wipe out the excess sealant from the bore.|4) operator and the inspector missed to ensure the complete removal of excess sealant from the bore after the completion of assembly.|5) The assembly operator and the inspector visually inspected the fillet formation and the completion of operations and any chip-offs but not the removal of sealant inside the bush as there was no dimensional requirements to be maintained on the bush the concentration on these areas was less. 