I noticed just a little bit of anti-freeze on the passenger side floorboard the other day on my 1991 F-150 with a 302. I figured the heater core was leaking. I pulled it out, hooked it back up inside the engine compartment so that I could put the heater core and the connections going to it all inside a bucket and test for leaks that way. So I run the truck up to temp (160 degree thermostat, yes I know thats colder than it should be but always seeing the temp gauge up in the 200 area just didn't seem right), top off the coolant, put the radiator cap back on to get the system up to pressure, run the engine for about 30 minutes, not a single drop of coolant in the bucket. So I'm thinking maybe the connections on the hoses to the heater core were a little bit loose and coolant was dripping out there and following the copper tube down and then down the side of the heater core and then onto my floorboard? The heater core looks brand new. I'm pretty sure it must have been replaced at some point before I got the truck because there was one screw missing from the housing. Is there anywhere else where coolant runs inside the dash area? I just want to make double-sure that my assumption about the loose hose clamps is correct. Like I say, it was just a small amount of coolant (maybe 30-40 drops) and it was directly under where the heater core is located. Any input would be greatly appreciated. Thanks.

Lloyd

 

It does sound like you had a loose connection to me. Usually when they start leaking, they tend to make a goey mess.

 

Well, for what its worth, I put the heater core back in and tightened up the hose clamps near the firewall nice and snug and haven't had any leaks so far.

Lloyd