New water pump not pumping through auxiliary output

[mpierce9]

hello, I've been trying to trouble shoot a heater problem for some time now. The original water pump never pumped through the auxiliary output nipple so I replaced it. Now the new pump doesn't either.

What am i doing wrong?


Water pump clearly in the center of the image. The hose with the worm clamp is around the fitting that is not pumping. I've tested this by removing the hose from the firewall and watching while the truck is running. I have burped the system multiple times with no change.


Any insight is appreciated.

Water pumps strong through the rest of the cooling system. Truck stays at 180-190 degrees.