W116 vacuum system

[koan]

Just been reading the central locking losing vacuum thread, trying to figure out where all the vacuum plumbing goes on a 6.9, My vacuum used to hold up for six days, now it lasts less than a day.

I have the vacuum line from the manifold to a rubber Y piece, each out of the Y has a blue/black one way check valve. Each of the check valves then connect to rubber X pieces.

The first X piece is central locking, two yellow lines, probably one to the vac tank and the other to driver's door vac switch, a third small diameter line runs across the firewall past the hot water tap and into the passenger compartment, Any idea what this third line is?

The second X has three small diameter lines that go directly through the firewall, I assume these are related to heating/air-con flaps, is that correct?

K

[kenny]

Just been reading the central locking losing vacuum thread, trying to figure out where all the vacuum plumbing goes on a 6.9, My vacuum used to hold up for six days, now it lasts less than a day.

I have the vacuum line from the manifold to a rubber Y piece, each out of the Y has a blue/black one way check valve. Each of the check valves then connect to rubber X pieces.

The first X piece is central locking, two yellow lines, probably one to the vac tank and the other to driver's door vac switch, a third small diameter line runs across the firewall past the hot water tap and into the passenger compartment, Any idea what this third line is?
there's a connection to cruise control actuatorThe second X has three small diameter lines that go directly through the firewall, I assume these are related to heating/air-con flaps, is that correct?
believe so, one will connect to vacuum supply tank in fender and others branch out to A/C stuff[/color]
K

[koan]

Kenny, you are spot on about the cruise control actuator, the line does not go through the fire wall as I said but to the servo. The three lines to the heat A/C box are a puzzle, the diagram I found only shows one, closes the fresh air flap when the A/C knob is in the last third of its range. Should have mentioned RHD, we only got the two knob set up, not the full climate control - maybe we are lucky!

Thanks.