I have a 89 f150 custom with the 302 5.0 auto. I had a problem with it, where a puddle of water coming from the heater core and leaking onto floorpan. It was like a rusty water and smelled kind of sweet with once the truck got hot it would steam up through the vents. After replacing the heatercore, my heat isnt hot, and it still leaks a little bit...anyone can help? Thanks Harry.

 

Hmm... First the simple stuff, did you use a new core and how are the hoses going to it? They can leak and because of their position it'll follow the heater core pipes into the truck. Also, did you clean out all the old fluid from the leak?

As for the heat not working, first feel the two hoses from the heater core, they should be warm to hot when the truck is fully warmed up. Both sides should be about the same temp. Then check to make sure you didn't disturb any of the vacuum lines that run to the various actuators under the dash. Try switching from hot to cold, and the various panel setting (defrost, floor, dash, etc) and see if you can hear or see the actuators moving the various doors.

I've put new cores in both my Bronco and F250 and they can both melt your eyeballs out.

 

I just rechecked everything today, as for when i said it was still leaking inside the cab, its not anymore. I did use a new core, and when i warmed it up, the hoses are definately hot to the touch. I'm sure i did clean out all the old fluid, drained the whole radiator and flushed the system. As for the checking the vacuum lines, where exactly are they located? Thanks again. Harry

 

under the dash mostly. They are black and white lines IIRC about 3/16" in diameter. You would have had to move them out of the way to swap the core. Not disconnect them, but at least hold them out of the way or otherwise wiggle past them. Pop the glove box door off and have a look and make sure everything is connected.

It sounds like one of the doors isn't working. There's also an actuator under the hood in the rear left hand side as you're facing the truck. It's over the heater/AC box. It's a little round thing connected to an arm with a vacuum line attached to it. Make sure that moves when you work the controls inside.

 

There is a white vacuum line on top of the heater box under the hood, it comes out of the bundle next to the engine and goes across the heater box to a vacuum motor near the passenger side hood hinge.. There is a good chance you broke it when removing the heater hoses.. It is known for getting brittle and breaking, if it is broken you can patch it with rubber vacuum line from the local parts store..

 

if its rusty looking,your going too long between coolant flushes too.