Table of contents: Coolant 🠇 Fuel 🠇 Motor oil 🠇 Air conditioning refrigerant 🠇 Brake fluid 🠇 Liquid leaks of unspecified nature 🠇 Vacuum hoses 🠇
Coolant
Caution: Before working on any of the cooling system components, refer to the information contained in paragraph "Safety first!" at the beginning of the Guide and in chapter 3.
1. Carefully check the radiator and heater coolant hoses along their entire length. Replace hoses that are cracked, bulging, or otherwise showing signs of deterioration. Cracks are easier to detect by squeezing the hose. Pay close attention to the clamps securing the hoses leading to the cooling system components. Overtightening the clamps can cause the hoses to become pinched or punctured, ultimately leading to leaks in the cooling system.
2. Inspect all components of the cooling system (hoses, mating surfaces, etc.) for leaks. If any problems of this nature are detected in the system components, replace the component or gasket (see chapter 3).
3. A cooling system leak will usually show up as white or rusty deposits in the area surrounding the leak.
Tip: A cooling system leak will usually show up as white or rusty deposits in the area near the leak.
Fuel
Caution! Before working with any of the power supply system components, please refer to the information contained in paragraph "Safety first!" at the beginning of the Guide and in chapter 4A.
4. Check all fuel line connections and their fastenings in the engine compartment and inspect the fuel lines for kinks, chafing and deterioration.
5. To detect a fuel leak between the fuel tank and the engine compartment, the vehicle should be raised and placed on reliable supports (see "Lifting and installing the car on supports"). Inspect the fuel tank and filler neck for any holes, cracks, or other damage. The connection between the filler neck and the tank is especially important. Sometimes the rubber filler neck or connecting hose leaks due to loose clamps or deterioration of the rubber.
6. Carefully check all rubber hoses and metal fuel lines coming from the fuel tank. Check for loose connections, deteriorated hoses, kinked lines, and other damage. Pay special attention to the ventilation pipes and hoses, which often pass near the filler neck and can become clogged or kinked, making it difficult to fill the tank. Check the fuel supply and return lines leading to the front of the vehicle, inspecting them carefully for signs of damage or corrosion. Replace damaged sections if necessary.
Motor oil
7. Inspect the areas around the mating surfaces of the cylinder head cover, cylinder head, oil filter and oil pan. Keep in mind that some very minor leaks in these areas are inevitable over time, and you are looking for signs of a major leak caused by a gasket failure. An engine oil leak at the base of the timing belt/chain cover or the front section of the transmission case may indicate a faulty crankshaft oil seal or transmission input shaft. If a leak is detected, replace the defective gasket or seal (see the relevant chapters of this Guide).
Air conditioning refrigerant
Attention! Please refer to the information contained in the paragraph "Safety first!" at the beginning of the Guide and in chapter 3 and focusing attention on the danger of touching the elements of the air conditioning system.
8. The air conditioning system contains liquid refrigerant, which is under high pressure. If the air conditioning system is opened and depressurized without the use of special equipment, the refrigerant will immediately turn into gas and be released into the atmosphere. If liquid refrigerant comes into contact with skin, it can cause severe frostbite. In addition, the refrigerant contains substances that are harmful to the environment. Therefore, it is important to prevent the refrigerant from escaping into the atmosphere.
9. If you suspect a leak in your air conditioning system, contact your dealer or an air conditioning specialist immediately. The leak will manifest itself as a steady drop in the refrigerant level in the system.
10. Be aware that water may drip from the condenser drain pipe under the vehicle immediately after using the air conditioner. This is normal and should not be a cause for concern.
Brake fluid
Attention! Please refer to the information contained in the paragraph "Safety first!" at the beginning of the Guide and in chapter 9 and focusing attention on the dangers of handling brake fluid.
11. Inspect the areas around the brake line connections on the master cylinder for signs of leakage (see chapter 9). Check the area around the base of the brake fluid reservoir for signs of leakage caused by a failed seal. Also inspect the brake line connections at the ABS hydraulic unit, if applicable.
12. If a drop in brake fluid level is evident but no leak can be found in the engine compartment, the front brake calipers, rear wheel cylinders and brake lines under the vehicle should be carefully checked, which is done by first raising the vehicle and placing reliable supports underneath it. A brake fluid leak is a serious problem that must be addressed immediately.
13. Brake fluid is a toxic substance with a watery consistency. New liquid is almost colorless, but becomes darker as it ages and is used.
Liquid leaks of unspecified nature
14. If there are signs that some liquid is leaking from under the car, but you cannot determine the type of liquid or the exact location of the leak, leave the car overnight and place a large piece of cardboard underneath it. Provided that the cardboard is located approximately below the leak, even the smallest leak will leave its mark on the cardboard. Not only will this help you pinpoint the exact location of the leak, but it should also help you identify the fluid by its color. However, keep in mind that some leaks may only appear when the engine is running!
Vacuum hoses
15. Although the braking system is hydraulically driven, the vacuum present in the intake manifold is used to operate the vacuum booster, which increases the force you apply to the brake pedal. The vacuum is transmitted to the amplifier through a large-diameter hose. Any leaks that occur in this hose reduce the effectiveness of the braking system and may affect engine performance.
16. In addition, many of the components located under the hood, especially components of emission control systems, use the vacuum created in the intake manifold and transmitted through small-section hoses for drive. A leak in a vacuum hose means that air is getting into the hose (does not follow from it), and this makes it much more difficult to detect a leak. One method is to use an old piece of vacuum hose to act as a stethoscope. Place one end of the hose to your ear (do not insert into the ear), and using the other end, examine the area around suspicious places. When the end of the hose is directly at the leak site, you will hear the characteristic "hissing" that accompanies a vacuum leak. Be careful not to touch any hot or moving parts as the engine must be running when performing this test. Replace any vacuum hoses found to be defective.