S2 owners - quick question on vac lines

[stevep2000]

Think I'm getting close to solving my heater malfunction, as I have no vacuum on the heater side of the vacuum system. Think it may be the check valve, either faulty or installled wrong way round, but looking at the diagrams on PET it shows vacuum coming off the brake booster, and the check valve being the first connection off that, i.e. all the vacuum connections are downstream of the check valve. On my S2, the vacuum comes off the inlet manifold, and the check valve is only on the part of the system for the heating controls, off one of the 'Y' connections. Is this right, or has someone got creative with the routing in the past?

 

[John Sims]

For the Turbo the check valve comes off the servo and tees to the vacuum reservoir and bulkhead connection. There is nothing else on that line.

While for the Turbo the attached may be of some assistance.

 

[stevep2000]

Thanks John, have been over most of the diagrams I can find (PET, Clarks, Rennlist), and can't find one that shows the right detail for the S2 - e.g., there's no 4mm vac line to the Brake servo (on mine at least). Heater is now fixed in that there was one cracked line & the check valve was wrong way round, but would like to confirm whether the blue check valve should only affect the heating side of the vac plumbing, i.e. not the fuel pressure reg / damper side?

 

[John Sims]

As far as I am aware the vacuum reservoir is only there to provide a stored vacuum to operate the heater valves. This is only connected to the engine as the engine provides a free source of vacuum.

The vacuum reservoir and one way valve should not be on the same line as the fuel pressure regulator or damper.