The heater only blows lukewarm.
2002 f150 heater core leak.
Disconnect the heater hoses from the firewall side.
Since it is only a small leak in the heater core we recommend simply sealing that leak and leaving your heater core in place.
The answered by a verified ford mechanic.
Fixing a leaking heater core will always be much easier than replacing one.
To remove the heater core disconnect the coolant lines from it.
Symptoms that indicate broken heater core.
You can do this by simply by adding bluedevil pour n go to your vehicle s radiator when your vehicle is cold.
Heater core is first guess which could run out the a c drain onto the ground but the trucks with rear heat air were known to develop a leak near the t fitting in the heater hoses which would drip on cylinder 4 cop and take it out.
This is because the core itself is compromised.
Heater no longer works cabin of vehicle smells like antifreeze the windows fog when the heater is running antifreeze leaks onto the ground or inside the cabin and the engine overheats if it runs for too long.
A heater core often goes bad due to leaking.
When the heater core fails in a 1997 2003 f150 the truck will begin to bleed antifreeze quickly.
Remove the coolant reservoir cap.
Position a drain pan underneath the drain hole on the radiator.
I replaced heater core on 2002 f150 5 4 supercrew because it was leaking.
Both heater hoses will be connected to nipples which go through the firewall and into the heater core.
To bypass the coolant around the heater core it is necessary to divert the heater hoses coming from the engine to somewhere other than the core itself.
Low coolant will cause an engine to run at a higher temperature which can result in extensive engine damage.