is there a check valve in the heater hose that goes to heater core on 1998 Ford F-150

i can blow through one way but not the other and theres a factory clamp on the hose witch is holding somthing

by in Mechanicsburg, IL on January 05, 2013
1 answer
ANSWER by , January 05, 2013
i doubt that there is a check valve maybe a heater core valve