Power Brake Booster

A power brake booster will increase the performance of the breaks on your vehicle, thereby making it much safer and easier to stop. It will give superior braking performance by boosting the pressure as you step on the brake pedal. A power brake booster also will allow for much less foot pressure to be applied on the brakes by the operator. So essentially what the power brake booster really does is make it so that you need to apply less foot pressure to the pedal when you want to stop the car. You will typically find the power brake booster mounted on the firewall attached to the master cylinder. The master cylinder is connected to the brake pedal.

Because engines produce vacuum during their normal operation, the power brake booster can utilize this vacuum. The vacuum enters into the power brake booster via the check valve on the booster. A rubber hose is usually used to connect the check valve to the engine. The check valve is a one-way valve. When the vacuum enters the booster it will not be allowed to escape back out. A power brake booster is divided into two chambers by a rubber diaphragm, which also has a valve. As long as your foot is not on the brake pedal, the vacuum is filling both chambers in the power brake booster. When you apply pressure to the brake pedal, the valve on the diaphragm closes to separate the chambers. As the diaphragm valve closes, an air valve opens to allow air into the chamber that is on the brake pedal side. This operation is what provides the power assist to the power brake booster.

Most power brake boosters have very few problems on their own and are typically very reliable. However sometimes there can be a loss of power to the power brake booster. For a power brake booster to work the engine must remain running. If you are driving along and your engine stalls you only have enough power reserve for at the most three break pedal applications. Your brake pedal will be extremely hard to press down after that. At this point it will be really hard to stop the vehicle.

You can tell that your power brake booster is bad if the brake pedal is hard to push down and has lost its vacuum feeling. If your power brake booster is bad you will need to replace it. As long as you can feel the vacuum pressure when you apply your foot to your brake pedal, then you know that your power brake booster is working correctly. As soon as you feel that vacuum go away you should immediately check your power brake booster to see if the vacuum hose is leaking or disconnected.

You can check your power brake booster yourself and save a lot of money on a brake repair bill. Power brake boosters are sold for various prices so it pays to shop around. There are several websites on line that sell power brake boosters. You can check out their online catalogs and browse through them to find the widest selection so that you'll get the right power brake booster for the right price.

For a lightweight vehicle all you need is a 7 inch power booster which will work fine for front desk rear drum application. However, if you have a four wheel disc on a heavier vehicle you will need an 8 inch diaphragm power booster because 7 inch booster may not provide satisfactory stopping power depending on the weight of the vehicle. You can also ask for advice for the correct size of power brake booster from an experienced car part salesman.

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