1993 Ford E150 Heater core replace/bypass

Howdy,

I had my mechanic bypass my heater core a few months back, but i now want to replace it due to the cold weather. I think I know how to get to the heater core and replace, but are there extra steps to take to "un-bypass"? If i just hook up the intake & output hoses, won't there be air in the system?

Thank you!

You'll have to bleed out the cooling system just like in any cooling system repair. Put a large pan under the radiator, turn heater to full hot. Refill the radiator to just above the core, run engine until temp comes up and let it bubble out. When ya stop seeing bubbles shut it off and let it cool then refill to proper level. I use the "Lisle No Spill Funnel" from Napa... $20-25 bucks. You won't need the pan under the radiator.

Thank you! I can't seem to locate the inlet/outlet/ heater core hoses under the hood. Should they be visible without removing anything? I can only find F150 videos and instructions online which don't match up.

Passenger side firewall, behind blower motor.