Apparently I’m losing coolant and my rear driver side passenger floor is wet?

Its in the side

Rear heater core that is. Takes a few hours to change, but not difficult

open rear hatch and remove
– rear seat
– rear hatch skid plate
– c pillar plastic cover (driver side) (you will need to disconnect seatbelt)
– b pillar plastic cover (driver side) (you will need to disconnect seatbelt)
– rear A/C plastic vent (thick black tube right under the b pillar plate)
– 2nd row seating skid plate
– plastic kick panel to expose the rear heater core assembly (there is a hidden pin under the carpet attaching it to the floor of the truck)

Disconnect the two hoses at the bottom of the heater core assembly

Then loosen and disconnect the two bolts on the metal tubing for the A/C (be careful you will get some green dye spray as the refridgerant blows out, so loosen lightly at first and it will just drip down through the floor of the truck)

Disconnect the 7 parts to the wiring harness from the truck to the plastic heater core assembly (you cant miss them)

Loosen the two brass bolts holding the assembly to the truck

Turn the assembly over and there will be 10 small bolts to take off and underneath that is the heater assembly…it just comes straight out. Replace and do the whole process in reverse.

Yes