After creating tanks: 

Tank 1(3289 kg)
Tank 2(2527 kg)
Tank 3(3344 kg)
The current tank is 3

After adding pumps: 

Tank 3(3344 kg)
 => pump 2(To tank 1)
 => pump 1(To tank 2)
Tank 1(3289 kg)
 => pump 2(To tank 2)
 => pump 1(To tank 2)
Tank 2(2527 kg)
 => pump 2(To tank 1)
 => pump 1(To tank 1)
The current tank is 2

Dumping Concorde (after using assignment operator): 

Tank 3(3344 kg)
 => pump 2(To tank 1)
 => pump 1(To tank 2)
Tank 1(3289 kg)
 => pump 2(To tank 2)
 => pump 1(To tank 2)
Tank 2(2527 kg)
 => pump 2(To tank 1)
 => pump 1(To tank 1)
The current tank is 2