940 vacuum pipes

TurnipSpeed · May 11th, 2021, 14:59

Hi, I wonder if the forum can tell me where the vacuum pipes are on my 96my 940 2.3lpt?
Silly question, but the Haynes manual is useless, and online diagrams can be hard to follow.
I know the advice for a stage 1 tune is to check for vacuum leaks, but there is no advice out there as to where the vacuum pipes are attached.
I know this advice will help a lot of us who are struggling to keep our beloved 940s on the road.
Thanks for any info.

TonyS9 · May 11th, 2021, 16:26

Anything pipe-like connected to the manifold and inlet is a vacuum pipe, if its not carrying fuel.

The large feed just after the air filter, provide vacuum to the block, also assisted by the Y piece and small pipe to the manifold.
Then when the throttle is closed the large pipe under the throttle body provides vacuum to the brakes.
There is a small diameter pipe (4mm-ish) connects the manifold to the turbo dump valve (built-into the turbo), so that it dumps pressure when the throttle is closed.
There may also be some pipes to join the manifold to the carbon canister that vents the fuel tank.

HPT and 95 have extra pipes for the turbo gauge and EGR + control valve. AC will have some vaccum pipes to drive the servos flaps and valves.

May 11th, 2021, 14:59	#1
TurnipSpeed TurnipSpeed Last Online: Jul 7th, 2023 15:53 Join Date: Jun 2012 Location: Peterlee	940 vacuum pipes Hi, I wonder if the forum can tell me where the vacuum pipes are on my 96my 940 2.3lpt? Silly question, but the Haynes manual is useless, and online diagrams can be hard to follow. I know the advice for a stage 1 tune is to check for vacuum leaks, but there is no advice out there as to where the vacuum pipes are attached. I know this advice will help a lot of us who are struggling to keep our beloved 940s on the road. Thanks for any info.

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May 11th, 2021, 16:26	#2
TonyS9 Premier Member Last Online: Apr 9th, 2024 21:44 Join Date: Jul 2009 Location: Holywood	Anything pipe-like connected to the manifold and inlet is a vacuum pipe, if its not carrying fuel. The large feed just after the air filter, provide vacuum to the block, also assisted by the Y piece and small pipe to the manifold. Then when the throttle is closed the large pipe under the throttle body provides vacuum to the brakes. There is a small diameter pipe (4mm-ish) connects the manifold to the turbo dump valve (built-into the turbo), so that it dumps pressure when the throttle is closed. There may also be some pipes to join the manifold to the carbon canister that vents the fuel tank. HPT and 95 have extra pipes for the turbo gauge and EGR + control valve. AC will have some vaccum pipes to drive the servos flaps and valves.

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