An Air Canada flight landed in Vancouver — four hours later than scheduled because the plane returned to Honolulu for an emergency landing.

The plane took off Monday night from Honolulu International Airport and had been in the air for two hours when the pilot saw an indicator about a valve. The pilot returned the plane carrying 158 passengers back to Honolulu. 

Air Canada spokesman Peter Fitzpatrick says the decision to make an emergency landing was routine procedure. He says the plane was making a heavier landing than normal because it was fueled up for a flight to Vancouver. 

Maintenance crews made repairs and the plane took off again for Vancouver.