98 F150 smells like antifreeze

Several weeks ago I noticed a puddle of antifreeze under my truck. I was going to add fluid and drive to the garage but it was full. Drove to the garage and they could not find a leak. They put it under pressure but it held at about 16 pounds. They ended up doing nothing but since then I smell antifreeze in the cab especially when running the heat. Last night the windsheild fogged over and the defroster would not defog. Strong smell of antifreeze and it seems to be coming through the vents. Still, the truck is not overheating or losing alot of fluid. Do you think its the heater core, and if so, any advice on replacing it?

I think it is the heater core, and I think you need to get it replaced.

Yep, it’s the heater core.

Best bet is to simply bypass it until you can get it fixed.

depends on where you live. if you NEED the heat, then you’ll have to get the heater core replaced.

if you live in new mexico or so cal then you could cut the two hoses which go through the firewall and get the correct size “hose barb” connector (at any decent hardware store) and rejoin the two hoses together, thus eliminating the heater core altogether. (this would also confirm that it is indeed the heater core that is at fault; but from your description it is pretty darned sure the core is gone)

This is a clssic heater core leak case. Best get it fixed; even if you live in an area where it is not cold, you still need the defrosters to clear the windshield when the humidity is high. I had such a leak in a 1971 Mercury Comet, and the large leak SPRAYED hot antifreeze all over the inside of the car. Very dangerous!!