Servo non return valve

[DavidM]

I've just fitted a dual servo from SVC to overcome a rock hard pedal (dual cylinders and balance bar) and weak leg, but didn't fit a non return valve in the vacuum line,do I need one? help appreciated on these final steps towards SVA. DavidM

[chris.richard]

I don't think so - I just have a straight (well, convoluted!) pipe from intake plenum to servo. It's a closed system.

[alfagene]

The non-return valve is there to allow you to have enough boost for a couple of applications of the pedal in the event that the engine stops. Without it you will lose all of the power assist on the brakes.

[chris.richard]

Good point.

[David May]

All the servos I ever saw, had the non-return valve built-in...

[chris.richard]

Just checked with SVC, their dual servo does not have a non-return valve.
Europa have one in their catalogue, Part no. LV15069, £29.99. Don't know size for pipe. It's not in their online catalogue.