I don't really understand what you want to know so I'll take a shot in the dark here and try to help you out the best I can with information you've given, (lol - none). The purpose of the check valve is to give you some power assist by holding the vacumn in the booster if the vehicle shuts down to give you some braking ability. Should hiss with enging running when unplugged from the booster. If unplugged from the hose with the vehicle off it should retain a vacumn in the booster. Booster problems (hard pedal) are sometimes caused by brake fluid leaking from the rear seal on the master into the booster and damaging the rubber inside. Look for fluid drip or peeling paint down the face of the booster, and remove the two nuts and pull the master away from the booster and visually check for wetness at the seal. Replace with a used/new one if needed but if you go for a used booster check it first. If it's a check valve you need, a parts supplier will have it or get one from the dealer. Some people recommend replacing master & booster as a unit but on and older vehicle if it's still o/k I'd only change whats needed.
I would say a power brake booster or a brake booster would be the same.
Sounds like it could be a vacuum leak at the power brake booster Check the lines to booster and the check valve at the booster Could be a defective brake booster also
Check for a vacuum leak under the hood Check for a bad vacuum brake booster Check for a bad "Check valve" on the vacuum booster
Perhaps a vacuum leak check power brake booster for leak and also inlet check valve on booster
Might be a vacuum leak Also check the check valve on the power brake booster
Could be a vacuum leak - check all lines and connectors udner hood and under the dash. Might be the check valve on the power brake booster.
The brake booster is part of the power brake system.
Still under warranty. This is their problem. Have them check the power brake booster.
No, the brake booster operates off of vacuum not electricity. If the booster isn't working then check the vacuum line going from the intake manifold to the booster. If the line is ok and not leaking then you need to replace the booster.
Perhaps a vacuum leak check power brake booster and check valve at booster
The power brake booster of a vehicle is replaced by removing the fluid reservoir, unbolting the booster from the firewall, and disconnecting it from the brake pedal. A new booster can then be connected and bolted into place.
If you have a power brake booster then there will be a vaccum line that runs to the brake booster on the firewall from the carburator. Check the booster for holes and broken fittings or buy a new booster. if no brake booster then brakes shouldn't affect vaccum