mjay2020

I replaced the Heater core on my 90GT. I bought the service manual for that car but when instructing to attach the rubber hoses from firewall to heater core, nothing was said on what to use to keep dry n no leaks. I went 2 autozone they advised me to use that plumbers tape that is used for leaking faucets or shower heads. When all said n done, the heater core was leaking in the car and when I would turn AC on, nothing was flowing out of the AC ducts. How do I fix this, Please? It's summer!
Thank You.

RTW0223

i replaced the core in my 92 and i never had to seal anything or what not.. i just attached the hoses and all was good

jimkaray

The hose clamps keep it sealed like any other push on hose connection. If its leaking you quite possibly cracked the one of the tubes where it connects to the core, or made a hole in the core when you did the install.

Mustangmutt

You should not need anything to seal the hoses to the pipes. If you are talking about sealing the core inside the case, I use foam tape to give the core a good air seal. If it is still leaking coolant inside you have possibly damaged the core during replacement. As far as no air flow from the vents, check to make sure the source hose it attached to the chek valve on the fire wall. Then check the hose connector behind the glove box. If it is the blower that is not working check the connectors at the resistor and at the motor.

mjr46

HOSE CLAMPS hold them on, if you forced the hoses on you may have broken the connections to heater core, cheaper heater cores don't have a support and you must be careful on install or risk doing it again.