Good day to all and thanks for any help!
I just had to replace the "water pipes" (metal cooling lines going to my rear heater).
Now i don't have heat back there! I lost some antifreeze during the process, and i had bypassed the rear heater while awaiting the new lines. I ran the truck until hot, radiator was full and had coolant in the overflow reservoir.
I thought by running the truck with the rear heater on, the air would be purged from the system! Apparently i am mistaken.
I ALSO HAD HEAT RIGHT UP TILL WHEN I BYPASSED THE REAR HEATER!
Any help, as always will be greatly appreciated!
Thanks,
dave

AS AN ADDENDUM, I REMOVED THE RADIATOR CAP AND RAN THE TRUCK UNTIL IT REACHED OPERATING TEMP. NOW THE REAR HEATER IS WORKING FINE!
YEA!