Heater Core Bypass, is my sketch correct? (1 Viewer)

[CaptainNemo]

Been doing some figuring. Want to bypass my front heater core but keep rear active. See bullet point 1 in on my sketch. Is my approach correct? How about points 2 and 3?

 

[Rifleman]

I've got to ask, why are you wanting to bypass the in dash heater core???

 

[CaptainNemo]

I'm experiencing an engine coolant leak. It's sort of dripping around the bell housing/transmission on to the ground. No apparent leak inside the truck in or around the floor. No interior smell. I need to conduct an experiment to isolate which heating circuit (front or rear) is leaking.

 

[Cruzerman]

Seems much more likely that the rear one is leaking. This is a common problem. The front leaking, not so much.

 

[CaptainNemo]

Thanks for your comment Cruzerman. The more I think about this, I think bypassing rear would be a first good test.

Also, updated my heater core bypass sketch. My previous sketch kept the heater control valve in the main circuit. Probably not a good idea. I moved point C1.

 

[CaptainNemo]

So my engine coolant was leaking from the rear heater system. I bypassed the rear heater system and rerouted the front heater core hoses as shown in the attached sketch. I used 5/8" Gates heater hose for the front reconnection and 1/2" Gates hose for the rear heater system. The GREEN high-lighted hoses are the new ones I added. I did eliminate quite a few hoses, clamps, and two metal pipes. Hope my visual aid helps for those who might need to bypass rear heater system.