I feel stupid to have to post this, but what is the flow directionality on the 7.3 IDI for the heater core? I've tried to search for this on the web, and I get contradicting results. Also, I just installed a coolant flush tee on what I consider to be the heater core supply side, but now I'm second guessing myself. Currently, my tee is installed on the hose that comes out of the top of the engine to the heater core. The other hose (The hose coming from the water pump) is untouched, because I'm assuming this is the heater core return hose.

Any advice would be greatly appreciated.

 

You are correct sir. This is info taken from the link below it,


Cooling System Function and Operation Part 3

Here is a video I made to verify this.

7.3 IDI Diesel coolant filter. - YouTube

And here is the thread all of this info is located in.

https://www.ford-trucks.com/forums/1...completed.html

have you considered adding a coolant filter while you're at it?

Good luck,

Mac.

 

You are either a mind reader or prophet. That's precisely what I'm doing.

 

Me too, but have a question. Does coolant flow close at the heater core when not set to heat? In other words if you add a coolant filter in the heater loop will it always get flow through it?

Thanks,
- Jeff

 

coolant is always flowing thorough the core.
the adjustments in the cab control the blend door,to block or allow heat,and at what rate with using the dial to open or close it further,along with blower motor to push air over it.
the coolant flow is always constant.

 

I can't remember what years, but the rangers had a valve hooked into the heater supply that would shut off flow to the core if heat was turned off. There's articles around on how to retrofit it to trucks like ours. Makes it a bit easier on the AC in the summer time.

 

Naw,

Just an old blind dog who finally caught a bone!

Batch,

Some guys run a bypass to redirect flow. It involves a bunch of ball valves that really bulk up the install. I just ran my direct. It looks real clean and works great.

Good luck,

Mac.

 

I did that in my truck, my AC doesn't work, but it still helps to cool the air down in the cab. The valve I used works like a bypass, it lets the coolant pass through like normal when open, then just loops it through the valve and out when closed. Its triggered by vacuum and I just pulled the line off the recirculate blend door and used it since its pretty much useless without AC. In the summer I move the level to recirculate and it shuts the flow down.

 

Coolant filter bypass system

Heater core vacuum bypass