Peter Humphreys wrote:
> I have a 1994 Honda Accord US Wagon.
> When the motor stops the brakes have no boost at all.
> I also have a Nissan Primera & the booster retains its vacuum when switched
> off, sufficient for about 3 applications of the brakes, which is normal.
> Could the non return valve to the booster be faulty? It has done 163,000
> km.

it should retain vacuum. as mike says, test & replace accordingly.