Heater vacuum diaphragm

[T.A.P]

I was working late at night, it was cold so I ran the car and turned on the heater. Everything was good until I saw coolant dropping down, I trace it back to the outlet heater hose (number 5 in the pic below) leading to the outlet vacuum diaphragm (not showing the in the pic). At first I though the hose deteriorated so I got another from supercheapautos. Perfect fit, but still leak. Its hard to determine exactly whats causing the leak cause there arent much space. I noticed that its fine when the coolant is cold but started to leak when it gets hot, if there's a crack or gap it should closes when the metal expands when it gets hot??

 

Anyway Im chasing the outlet vacuum diaphragm that connects to the no.5 hose. Im hoping that this is not the case as I;ll have to pull the whole assembly out to replace it. fingers crossed.

 

PS: its a 75 260z

 

[maddos]

It's more than likely the shut off valve connected to number 5 hose.

They seem to leak where the actuator rod leaves the assembly.

They're hard to find new for the early series 260.

[T.A.P]

By outlet I mean where the coolant flows back into the radiator, but I guess the correct term is "shut off" 

I'll probably patch it up by using quicksteel or something similar.