3 vacuum pipes from small 4 port pipe

L322 TD6 2005 The vacuum pipes were shot and had fallen apart. So renewing with 3mm silicon hose.
From the vacuum pump is a pipe with 4 output ports on it behind the oil filter,
1 is blocked off
2 goes to engine mount actuator about 18 inches away toward the back of the engine under the inlet manifold.
3 goes to Turbo vacuum reservoir across the top of the engine at the front.

But where should the last pipe go and what device does it feed?

Thank you

Sounds like your EGR pipes. Sometimes one on solenoid is disconnected for egr blank.
Pics?

RangeRoller dt said:

Sounds like your EGR pipes. Sometimes one on solenoid is disconnected for egr blank.
Pics?

Click to expand...

RangeRoller dt thanks for your reply - there is a black pipe with a blue stripe that connects the EGR valve on the manifold and heads off towards the back of the engine underneath the inlet manifold. So I will look into if there is a solenoid down there somewhere. Not a lot of room to work or view under the inlet manifold.
I will try and get some pics but heating pipes do seem to get in the way - think I might invest in a gooseneck camera.