Brake padle is very hard when pressed

I own a pontiac bonneville SSE 1989. The brake lights are alwayes on, not just that but also the brake padle is very hard when pressed and it requires a lot of pressure to make the car stop. Please does anyone know what could be the problem.

Sounds like the power brake booster has gone bad and needs to be replaced or you have a vacuum leak at the booster. I would believe that the booster itself is bad given your description. Take it to a mechanic and have it replaced. Also have him check the master cylinder as it may need to be replaced too given the age of your vehicle.

Your SSE should have the Teves anti-lock brake system like my 90. This is an electro-mechanical assisted brake system rather than a vacuum assisted system. A hard pedal might mean a faulty pump assembly which would mean that's it's very dangerous to operate the vehicle. The pump builds pressure upon turning the ignition on and will continue to run until adequate pressure is reached. If you do not hear a "buzzing" sound coming from the master cylinder area, check the fuse first. I want to say fuse 8 or 9 but consult your manual to be sure.

Another part of that system is the accumulator. This is what stores the pressure. From what I understand, this is a wearable part and has a lifespan of roughly 10 years. You're well above that. Fortunately, they are still available from GM but they are about $150-$180. In my experience, the accumulator causes poor braking preformance. Your's is either totally shot or you have a pump problem.

Thanks for the information Randman1 I was not aware of that particular system. At least someone here keeps me straight on the Bonneville! Of course only GM would have to throw a monkey wrench into a relative basic system to make it complicated!

Yea, it is a bit screwy. I guess the story goes something like this. It was developed by a German company for use in Europe and other countries that are primarily running deisel vehicles. I guess deisels do not produce enough vacuum to be used in a power assist brake system so this is why it's electromechanical. The design was bought by Teves later. Similar systems are found in older Mercedes, Audi, Buicks (Reatta and Lesabre T-Types), ect.

GM... always thinking outside the box. :screwy: