Not practical to try to fix a heater core. Replace it with a new one.
Try the repair tips on the Autozone web site.
Does it have a funny smell? it could be leaky heater core
How do I replace heater core on 98 Buick lesabre
How do you install a heater core on a 1998 buick lesabre
replace heater core on 92 buick century
I believe that is a bypass tee that allow coolant to go to your heater core for your heater.
Under dash, passenger side, inside the vehicle, mounted on the firewall.
The heater core is mounted to the passenger side firewall on the 1988 Buick Electra 307. The blower motor needs to be removed to access the heater core.
It's in the heater core housing.
It could be the heater core leaking.
Im asking how to change the heater core. I don't have the answer.
You can bypass your 1988 Buick Skylark heater core by removing the heater core water supply hoses. There will be to water hoses. Connect the water hoses to each other.