E30 series BMW 3

since 1983-1994 of release

Repair and car operation

+ 1. Maintenance instruction
+ 2. Maintenance
+ 3. Engine
+ 4. Cooling system
+ 5. Heating and ventilation
+ 6. Fuel system
+ 7. Exhaust system
+ 8. Transmissions
+ 9. Coupling
+ 10. Brake system
+ 11. Running gear
+ 12. Body
+ 13. Electric equipment
- 14. Good advice
   14.2. Changed numbers
   14.3. Purchase of the old car or mysterious set of figures and letters
   14.4. Durability of the car
   14.5. About parallelism of bridges of the car and the trailer
   14.6. Preparation of the car for winter
   14.7. Rule 35
   14.8. Choice of the second-hand car
   14.9. Engine oils
   14.10. That it is necessary to know, changing oil
   14.11. Emergence in deposit oil
   14.12 whether. It is possible to mix import oils?
   14.13. "Eats" much, but silently goes
   14.14. It is rather live, than it is dead …
   14.15. It is not got - good advice
   14.16. Visit to car-care center
   14.17. A gear belt for a drive of the mechanism of a gazoraspredeleniye
   14.18. Wear of pistons
   14.19. Valves
   14.20. Bearings of engines
   14.21. Engine pollution
   14.22. As the conditioner works and what to do, if it failed
   14.23. Conditioner: not only "pluses", but also "minuses"
   14.24. Rules of service of the conditioner
   14.25. It is not necessary to stir antifreeze with antifreeze …
   14.26. That it is necessary to know upon purchase of the air filter
   14.27. Engine overheat
   14.28. That it is necessary to know to the owner of the car with the injector engine
   14.29. Accumulator
   14.30. Possible malfunctions of the storage battery
   14.31. What to do with the failed generator
   14.32. The belt is guilty, and we blame the generator
   14.33. Catalyst
   14.34. Rub in one - or how to save the catalyst
   14.35. Probuksovochka
   14.36. Features of operation of brake system
   14.37. Malfunctions of brake system
   14.38. Brake liquids
   14.39. ABS: natural choice
   14.40. Rims
   14.41. We update rims
   14.42. Scheme of marking of a car tire
   14.43. Metal corrosion
   14.44. Automake-up
   14.45. What creaks?
   14.46. Hatch
   14.47. Safety cushion: troubles or pleasures?
   14.48. We fit well?
   14.49. Anticreeping "immunodeficiency"
   14.50. Why headlights grow dull
   14.51. "Galogenki"
   14.52. About the correct adjustment of headlights
   14.53. Electric motor
   14.54. From change of places "composed" changes nothing?

14.38. Brake liquids


That it is necessary to know to the consumer

Purpose of brake liquids – to transfer effort from the main brake cylinder to the wheel. Task though narrow, but extremely responsible: the brake system has no right to refusal under no circumstances. Requirements to properties of brake liquids are defined by this condition. They consist in the following.

Boiling temperature. Experience shows that working temperature of brake liquid in most flashpoints of system approximately is as follows: 60 ° With at movement on the highway, 100 ° With in the city and 120 ° With in mountains. But it on the average, and in intense usiloviya it quite often reaches 150 ° With and even can begin to boil more as, for example, the brake shoe at several emergency braking heats up to 600 ° S.Poetomu liquid in an adverse situation, and it threatens with accident: the volume of the main cylinder is insignificant (only 5-15 ml) and as soon as the volume of vials of steam in system will exceed this size, brakes completely will refuse. But also before, at the small sizes of steam jams, efficiency of brakes already considerably falls.

At modern brake liquids the temperature of boiling is much higher critical (that is 150 ° C), but these cannot be under a delusion. The substances entering into their structure, generally are very hygroscopic, that is easily absorb moisture from air, and rubber cuffs serve as a bad barrier to this process. The boiling point of the "moistened" liquid in comparison with "Sukhoi" is much lower, it easily falls to critical size and even further. Therefore in passport data always specify two values of temperature of boiling: without moisture and with the maintenance of 3,5 % of water. If the last is small, in system with disk brakes it is not necessary to apply such liquid.

Frost resistance. It is obvious that the liquid serving for transfer of pressure, should keep acceptable fluidity even at strong cold. It is accepted that its viscosity should not exceed 1800 mm2/with at-40 ° With for usual execution and 1500 mm2/with at-55 ° With for the special northern. At a product choice for use in the conditions of severe winter it is necessary to pay attention to it.

Compatibility with consolidations. The substances containing in brake liquids, inevitably cause swelling of sealing rubber cuffs, however this influence is limited by existing technical standards.

Anticorrosive and greasing properties. For moving details of brake system working liquid is urged to serve as natural greasing as other antifrictional products in their zone of a friction are not present. All these requirements are satisfied with application of special additives and additives in commodity products.


"Neva" – the first-born of the modern row who nowadays fairly out-of-date and has been removed from mass production (small-scale here and there remained). The main components – glikolevy air and polyair with addition of an anticorrosive additive. The temperature of boiling makes 195 ° With without moisture and 138 ° With at the maintenance of 3,5 % of water. The standard of frost resistance is sustained. "Neva" has color from light yellow to the yellow. The main shortcoming – the increased hygroscopicity owing to what in a year of operation the temperature of boiling comes nearer to the critical. Only taking into account this circumstance also it is possible to use "Neva" which has no other restrictions to application on cars of any brands.

"Tom'" is developed on Neva liquid replacement for wide application. Color – in limits from light yellow to yellow, as at "Neva". As a part of "Tom'" – concentrated glikolevy air, polyair, бораты, target additives. Temperature properties of a product are improved: boiling in a "dry" look – 220 ° With, in "humidified" – 155 ° With, viscosity at-40 ° From no more than 1500 mm2/pages. Saturation by moisture, near-critical, comes at this liquid approximately in two years of work. As a whole on ekpluatatsionny qualities "Tom'" on the standard international classification satisfies to modern standards of DOT-3 is a mass, "shirpotrebny" class without any special restrictions on application.

"Dew" – a product relating to the most perfect type. The main component – borsoderzhashchy polyair along with additives of a special purpose. Color – from light yellow to light brown. Indicators of boiling are as follows: in a "dry" look – 260 ° With, in "humidified" – 165 ° With, thus a critical indicator (150 ° C) it is reached only after three years of finding of liquid in a hydraulic actuator of brake system. According to the international classification "Dew" satisfies with everything to norms of the class DOT-4 that for today is the highest level of operational qualities. "Dew" without restrictions suitable for use in modern domestic and foreign cars.

Foreign products. Today in our market it is possible to meet a set of import brake liquids (Brake Fluid). If such liquid is recommended by the manufacturer for any cars and thus has DOT-3 or DOT-4 marking, it can be used equally both in foreign cars, and in domestic cars. As to operational qualities, at comparison in the corresponding class (or DOT-4) import liquids are approximately identical to DOT-3 to our "Tom'" or "Dew" and have no any special differences from them.