Testing brake vacuum check valve

[skodajag]

On my Series 2 car there is a slight delay before the servo kicks in on the brakes. I suspect the brake vacuum check valve on top of the reservation tank. I’ve got the valve off and on the bench but are not sure how to test it. Advice appreciated.

[skodajag]

Ok. In the absence of replies I tried to figure out how it works. With the top inlet/outlet I’m able to suck air but not blow it. With the lower inlet/outlet I’m able to suck air and blow it. Am I right in thinking it’s working?

[caveman]

Jonathan,
There’s plenty on this within the forum, just search for example: air reaction valve
Also some information here about missing spring etc;
https://forums.jag-lovers.com/t/e-type- ... ve/76037/7

[mgcjag]

Iv never blown through the check valve...however manifold vacume is "sucked" at the top creating a vacume in the tank and the servo. When engine is switched off the vacume in the tank still holds a vacume in the servo... there is a detailed drawing in the service manual showing the brake system and the check valve..Steve