Use greased lightening "stop it" IT WILL MAKE A NEW SEAL AROUND THE PUMP SEAL, IF ITS A HEAVY LEAK INSERT TWO BOTTLES INTO THE COOLING SYSTEM . TRUST ME IT WORKS AND I HAVE DONE 77,000MORE MILES SINCE ON MY SKODA OCTAVIA TD
IF THE PUMP IS NOISY THEN REPLACE THE PUMP, OPEN CAM CASING, CUT BELT OFF, DONT TURN THE PULLEYS, UNDO PUMP AT BOTTOM, COMES OFF WITH BOTTOM PULLEY, DO FROM UNDERNEATH CAR, REPLACE PUMP, NEW BELT, AND AWAY YOU GO
DAVE D1, November 2008