Feb 21 (Reuters) - Japanese investigators have found problems in equipment that controls a fuel-tank valve on a Boeing Co 787 Dreamliner jet that was being probed for fuel leaks, the Nikkei newspaper reported on Thursday.
The fuel leak, found in a Japan Airlines Co jet as it taxied to a Boston runway on Jan. 9, came amid battery problems that have since grounded the Boeing 787 Dreamliner fleet globally.
There were deficiencies in the way electrical-insulating paint was applied to a mechanism that opened and closed the fuel-tank valve, the Nikkei said, citing people familiar with the matter. Transport ministry investigators also found foreign matter on a switch that operated the same mechanism.
The investigators believe that this caused the switch to send a signal that the valve was closed when it was still half open -- causing the leak, the Japanese daily said.
The ministry is in talks with the U.S. Federal Aviation Administration and Boeing about ways to resolve the problem, the newspaper said.
The same 787 involved in the Jan. 9 fuel leak in Boston leaked fuel from its left wing nozzle at Tokyo’s Narita International Airport on Jan. 13.