To purge hose, crack the manifold hose at the manifold fitting and bleed a small amount of refrigerant from the line before retightening the hose connection. The refrigerant will expel the _____from the line To purge hose, crack the manifold hose at the manifold fitting and bleed a small amount of refrigerant from the line before retightening the hose connection. The refrigerant will expel the _____from the line refrigerant oil vapor air