Just noticed a very small stream of antifreeze running down the drivers side of the passenger side floor board from time to time not much but very little.
Im thinking heater core but the only thing keeping me from it is this seemed to start the day after i changed both heater hoses. I have never changed a heatercore in anything or really even know what one looks like. Is it a bad job?
its a 1974 f-100 360 engine no air conditioning.

 

The day after changing heater hoses? It's very possible that while removing/installing the hoses that the heater core developed a leak. My '79 has A/C and it was a mild pain to swap the heater core. I have heard the non A/C heater cores are much easier to swap, and I'm about to find out myself as I need to swap one in my '78.

 

Maybe the hose is leaking at the clamp ?

 

Agree with Million - first thing to check is the cab end of the new heater hoses. The core input/output fittings stick out through the cab wall. That's what you attached the hoses to. If it's leaking there, it may go in through the passage holes. Normally there's supposed to be a little foam spacer over the fittings, between the end of the hose and the cab wall, so that any hose leaks don't go into the cab.

Next most likely is that you cracked one of the fittings while changing the hoses. they're fragile, especially if the core is old. In this case, the core has to come out.

Another possibility is unfortunate coincidence - the core sprung a leak.

Changing the core is not a big job. But it's a pain because you have get down under the dash, find all the bolts holding the heater box on, and then wiggle it out of there. On my 79 F250, I found a bolt that holds the passenger end of the dash to the body, and removing that let me wiggle the dash opena bit to let the heater box out more easily.

There are several sizes of heater cores for these trucks. Get the old one out before ordering the new one so you get the right size.

Personal preference: they make new non-toxic antifreeze based on propylene-glycol instead the highly toxic ethylene-glycol. Works just as good. A lot safer to work with.

 

Good point fred. It's a lot easier on the local cats, dogs and children if you use the less toxic stuff. Because, let's face it, these trucks are going to leak somewhere.

 

I agree, it could be loose heater hose clamps, be careful not to overtight the hose clamps, or it will damage the heater hose.

Here's a thread on heater core replacement. https://www.ford-trucks.com/forums/s...23&postcount=3

 

I hope its just a hose leak but my guess is that you damaged the core. If you do have to change it Mil1on should be able to get you the location of the bolts necessary for removal. On my 78 there is one nut under the hood on the firewall. Without the manual I don’t think I would have found it.

 

custom1, here are some pictures in my gallery showing the cables layout, heater duct layout and the nut location of heater core assembly. https://www.ford-trucks.com/user_gal...&albumid=18841
--buck--

 

Here is some additional information, have fun and be patient if you do plan on removing heater assembly http://broncohq.com/pdf/72-79/body/heatercontrols.jpg

 

wow thanks for all the input guys, When i took the hoses off they came off and on very easily and just tonight i noticed a bit of antifreeze leaking down the firewall under the hood so im hoping its just a hose leak Your probably wondering why i havn't just tightened it yet and so am i but im extremely busy for some reason and just havn't. I promice ill do it tomorrow and let ya all know what happens
Thanks.
Just occured to me that i put the same size hoses on both inlets. Shouldnt one have been 5/8 and one 3/4???

 

The hose should be the same size.