1999 Nissan Almera N15
I noticed the problem awhile ago that occasionally the brakes wouldn't disengage. If I turned the vehicle off and pumped the brake pedal a few times the brakes would disengage. Now the only way I can get them to disengage is to turn off the car and disconnect the vacuum hose from the brake booster.
If you look at this diagram it looks like there is a check valve that maybe releases the vacuum pressure when you let off the brakes?
Is there a way I can test this further, should I just replace the check valve, or am I looking in the right place at all?