Hi, so Im replacing the HC in my truck and the extender tube that runs through the fire wall keeps leaking on me. I replaced the clamp and the O ring with one from toyota still leaking. Has anyone one here experienced this problem before. Iwas thinking about just puting a little RTV on there but thought I would ask here first. Thanks for the help John

 

i take it that your leak is at the heater core connection?/

Every thing nice and clean ??

Did you cut the new o ring or have it twist out of shape when putting it together??

I doubt RTV will fix the problem

 

Yep right at that connection . It is all clean and the
O ring looks good.

 

After market heater core ??

The Toyota o ring might not be sealing due to a size difference.

 

Yep after market heater core. I tryed a little bigger o ring but im going to get a new one and try it again

 

Are you sure it's the brass tube and not the old rubber hose?
I managed to cut my heater core supply hose during a rebuild.

 

Nope not the hose replaced them :\

 

Fellas I got it thanks for the help you all were awesome.

 

Glad you got it sorted out!!

Just what did the trick?? Different size o ring??

 

Yep bigger O-ring and rolling the o-ring onto the expansion tube