How does a brake booster work on a turbo car?
Brakes use engine vacuum to assist the driver in pushing the brake pedal down (vacuum servo). With turbo boost you create positive manifold pressure (i.e. boost) and now the brake booster does not have a vacuum to work with to assist with braking!
How do you check brake booster pressure?
Turn the engine off, then repeatedly press the brake pedal slowly. When you pump it the first time the pedal should be very ‘low’— meaning not much pressure resistance. As you pump the pedal, the pressure should become firmer, which will indicate that the brake booster is not leaking.
How does a brake booster work on a Porsche Cayenne?
The brake booster is a device that uses vacuum pressure from the engine to decrease the amount of effort needed to push down the brake pedal. It does this by using a large vacuum diaphragm controlled by a small electric air pump.
Where is the master cylinder reservoir on a Porsche Cayenne?
Shown here is both the master cylinder reservoir (green arrow) and brake booster (yellow arrow) on the Porsche Cayenne. Removing the plastic cover at the rear of the engine bay helps gaining access to the vacuum line from the pump to the brake booster.
Why does my Porsche Cayenne make a hissing noise?
You’ll want to check if the brake pedal goes to the floor with the engine off. If it doesn’t, you have a problem with the system. Usually, this is accompanied with a hissing noise as there will be a leak in the system, either at the brake booster diaphragm or the air line to the vacuum pump.
What causes a soft pedal on a Porsche Cayenne?
If the fluid level is low, check for leaking brake fluid under the car and also at each brake caliper. If the fluid level is fine, try bleeding the system. A soft pedal can be caused by air in the brake lines. See our article on Bleeding Brakes for more information.
The brake booster is a device that uses vacuum pressure from the engine to decrease the amount of effort needed to push down the brake pedal. It does this by using a large vacuum diaphragm controlled by a small electric air pump.
Shown here is both the master cylinder reservoir (green arrow) and brake booster (yellow arrow) on the Porsche Cayenne. Removing the plastic cover at the rear of the engine bay helps gaining access to the vacuum line from the pump to the brake booster.
You’ll want to check if the brake pedal goes to the floor with the engine off. If it doesn’t, you have a problem with the system. Usually, this is accompanied with a hissing noise as there will be a leak in the system, either at the brake booster diaphragm or the air line to the vacuum pump.
If the fluid level is low, check for leaking brake fluid under the car and also at each brake caliper. If the fluid level is fine, try bleeding the system. A soft pedal can be caused by air in the brake lines. See our article on Bleeding Brakes for more information.