Why can't the brake pedal be pressed down when starting the car?

1 Answers
DeIsla
07/30/25 5:08am
The reasons why the brake pedal cannot be pressed down when starting the car include a faulty vacuum booster pump, stepping on the brake after the engine is turned off, and lack of maintenance of the brake system. Faulty vacuum booster pump: The force applied to the brake pedal is amplified by the brake booster pump. If it fails, the brake loses its main power source, making it impossible to press down. In this case, immediate repair or replacement is required. Stepping on the brake after the engine is turned off: This is also related to the brake booster pump. The brake booster pump only continuously generates vacuum when the engine is running. When the engine is off, it relies solely on the residual vacuum, which typically allows only a few presses before becoming ineffective. In this situation, a short wait is sufficient. Lack of maintenance of the brake system: Too much debris in the master cylinder, poor sealing, failure of the vacuum booster pump, dirty brake fluid or mixing different types of brake fluid causing vapor lock when heated, leakage in the master or wheel cylinders, or leaks in the air reservoir or pipe connections. In this case, maintenance at a 4S shop is necessary.
Was this review help?
11
5
Share
More Forum Discussions

How Many Years Can a General Tire Be Used?

Generally, a tire can be used for 5 years. After 5 years from the date of manufacture, the tire needs to be replaced regardless of its wear level. If a car is driven 20,000 kilometers annually, the tires should be replaced every 3 years. If the car is driven 10,000 kilometers annually, the tires should be replaced every 4 to 5 years. Here are methods to determine whether tires need replacement: Check if the tread wear is close to the wear indicators. Generally, the wear mark height for passenger car tires is 1.6mm. When the tread depth wears down to 1.6mm, the tires need to be replaced. Check the tire production date to confirm if it has expired. The production date is located on the sidewall of the tire, represented by a 4-digit number. The last two digits indicate the year of production, and the first two digits indicate the week of production. The service life of a tire is typically around 5 years. If it exceeds 5 years, the tire is considered expired and should be replaced promptly. Inspect the tire for any abnormal conditions such as cracks or bulges. Tire damage includes tread cracks, tread bulges, missing tread rubber, severe sidewall wear, or multiple punctures by foreign objects. If the damage is severe, the tire should be replaced immediately.
17
2
Share

Is the Tiguan L four-wheel drive?

The Tiguan L is available in front-wheel drive and front-engine four-wheel drive configurations. Here is more information about front-wheel drive and front-engine four-wheel drive: 1. Front-wheel drive (FF) means the engine is positioned at the front and drives the front wheels. The advantages include a simple mechanical structure, good engine cooling conditions, spacious interior, easy layout, reduced vehicle weight, better fuel efficiency, and convenient maintenance. The disadvantages are that since the front wheels handle both steering and driving, high-speed stability is relatively poor, the drive wheels are prone to slipping when climbing hills, and the vehicle is more likely to roll over during high-speed descents. 2. Front-engine four-wheel drive means the engine is positioned at the front and all four wheels drive the vehicle. Since all four wheels have power, compared to designs that rely solely on front-wheel or rear-wheel drive, front-engine four-wheel drive offers superior handling performance. The advantages of front-wheel drive are all related to the drivetrain—since front-wheel drive vehicles lack a driveshaft connecting to the rear wheels, the components are fewer and more concentrated, resulting in direct power transmission. Therefore, front-wheel drive vehicles are cost-effective, efficient, spacious, lightweight, and fuel-efficient.
2
3
Share

How to Deal with Oxidized and Whitened Red Car Paint?

Through grinding and polishing to remove the oxidized layer of the paint, the vehicle can regain its luster, temporarily restoring the color to its original state when it was new. Followed by coating. Coating involves applying a protective film over the car's surface to isolate and protect the paint. This film itself is not affected by external oxidation. Repainting is a common method to restore the gloss of car paint. However, repainting is often constrained by factors such as raw materials, spraying equipment, and construction techniques. The coating material contains silicone, rich in blemish cream and titanium dioxide, both of which are extremely stable in nature, forming a protective layer on the car paint surface that lasts up to three years.
4
1
Share

What to do if the driver's license expires within one year?

If the driver's license has been expired for less than 12 months, you can proceed with the renewal as usual. When the driver's license expires, you should go to the vehicle management office to apply for a replacement. You need to bring the identity proof of the vehicle owner and standard photos of the vehicle, etc. If the driver's license has expired, it is as if you do not have a driver's license, and the vehicle cannot be driven on the road. If caught by traffic police, the owner will be detained. In insurance contracts, a vehicle with an expired driver's license is considered unqualified. If a vehicle insurance accident occurs, no claims will be paid.
12
4
Share

How to Test the Engine Oil Level Sensor?

Disconnect the wiring harness plug of the engine oil pressure sensor and remove the sensor. Screw the hose connector of the oil pressure gauge into the threaded hole of the oil pressure sensor. Place the oil pressure gauge in a location where it will not come into contact with rotating or high-temperature engine components. Start the engine and check for any oil leaks at the oil pressure gauge connection. If leaks are found, turn off the engine and retighten the connection. Run the engine until it reaches normal operating temperature, then check the oil pressure gauge readings at both idle and 2000 r/min.
19
2
Share

How to Remove and Replace the Low Beam Headlight of the New Sylphy?

Open the engine compartment cover, locate the rear cover of the headlight at the headlight position, unplug the connector, and unscrew the bulb. More related information is as follows: 1. The low beam headlight is designed for close-range illumination, with a large coverage area (160°) and a short illumination distance, and the focus cannot be adjusted. The low beam must be turned on in the following situations: driving in areas without streetlights at night, driving at dusk when it is relatively dark or at dawn when the light is just appearing; if encountering heavy fog, snow, or heavy rain that obstructs visibility, the low beam must be turned on even during the day; on some roads where there are lighting facilities but the brightness is insufficient, the low beam should also be turned on. 2. Although the low beam has an illumination distance of about 30 meters, it has a very noticeable beam cutoff line. Most car low beams have an illumination distance of 30-40 meters, with the beam cutoff line at about 12-18 meters. The area in front of the beam cutoff line is brightly lit, allowing clear identification of objects, and a clearly visible illuminated area of 2-3 meters in diameter can be seen on the ground. The area from behind the beam cutoff line to 30-40 meters mainly relies on ground-reflected light sources. In this area, brightly colored objects can be distinguished, but dark-colored stationary objects on the road are not easily noticeable.
5
4
Share
Cookie
Cookie Settings
© 2025 Servanan International Pte. Ltd.