the two plastic vacuum lines that go into pass firewall ......???

[cecil bass]

where do the two plastic vacuum lines go that run into the pass side firewall ? ? i need to replace them both they are dry and ready to crack ..... thanks everyone !!!

 

[RmvBfrFlght]

A SWAG here, one is to operate the HVAC doors. The other is to operate the heater coolant valve on/at the intake manifold. In the car they would both go to the HVAC control head. The one line is manifold vacuum to the control head. While the other is from the control head to the heater coolant valve.

RemoveBeforeFlight

 

[cecil bass]

how many inches of vacuum should i be getting at both lines ??

 

[Chuck Leeper]

Whatever the engine is pulling, would be my suggestion.