AN MD80 ON LNDG ROLLOUT DECLARED AN EMER DUE TO LOSS OF L HYD SYS PRESSURE AND QUANTITY.

Narrative

FLT XYZ. ON LNDG IN BOS RWY 27; THE L HYD QUANTITY AND PRESSURE DROPPED TO ZERO ON THE ROLLOUT. I STOPPED THE ACFT; SHUT DOWN THE L ENG AND SECURED THE HYD SYS. I THEN CALLED FOR FIRE TRUCKS TO CHK THE ACFT FOR DAMAGE AND TO PROVIDE A FIRE GUARD DUE TO THE FACT THAT WE HAD LOST ALL HYD QUANTITY AND I DID NOT KNOW WHERE THE LEAK WAS. WHEN THE FIRE TRUCKS ARRIVED THEY ADVISED ME THAT THEY THOUGHT WE HAD FUEL LEAKING FROM THE ACFT. WE SECURED THE ACFT AND DID AN ORDERLY DEPLANING OUT THE AFT STAIRS. WHEN I GOT OFF THE ACFT I ASKED THE FIREMAN TO SHOW ME THE FUEL LEAK. HE DID AND IT WAS NOT A FUEL LEAK. JUST HYD OIL. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE LOSS OF THE L HYD SYS PRESSURE AND QUANTITY WAS CAUSED BY A FAILED L REVERSER CTL VALVE. THE RPTR SAID THE L REVERSER WAS HARD TO STOW AFTER LNDG AND THE REVERSER UNLOCK LIGHT REMAINED ON CONTINUOUSLY. THE RPTR SAID THE APU WAS NOT RUNNING SO NO HYD FLUID ENTERED THE APU TO CAUSE SMOKE IN THE CABIN.