The brake system is capricious and requires constant attention. Still, almost half of its elements are consumables. There is also brake fluid (TJ) on this list. It would seem that she would do? Splashes itself in the compensation tank, does not decrease. The trouble is that modern TJs are hygroscopic - they absorb moisture well. Water in the system provokes corrosion, due to which, in the end, the pistons sour and leakage occurs. But, most importantly, a damp liquid can boil at the most inopportune moment. Sometimes, a few intense braking is enough for vapor bubbles to appear in the system. The result will affect immediately - the hard pedal will go to the floor.
Of course, manufacturers provided this by setting a working corridor for each class of TJ. The boiling point is “dry” at the upper boundary, and the moistened (up to 3.5%) liquid is at the lower boundary. Just how to control it? Do not take monthly analysis to the laboratory! Not at all, because the frequency of replacing the TJ is indicated by the manufacturer. VAZ, for example, requires you to do this after 45 thousand kilometers or every three years.
(The option is not the most burdensome - the owners of the Ferrari are forced to repeat the procedure after five thousand!) In between you can drive relatively quietly, from time to time still looking into the tank. Decrease, turbidity or precipitation is a signal for an extraordinary revision. However, the arithmetic mean norms on faith should not be taken. What if during the repair they poured stale goods? Or did they market a perfectly packaged fake in the market? It would be nice to have specific numbers - they are not joking with brakes. No problem - in self-respecting services, they have acquired a device that measures the boiling point of TJ. In the matter of traffic safety - an extremely useful thing.
The next question: what to replace? Will you somehow manage to save money or, without sparing your wallet, buy all the best? Nowadays, products of classes DOT-3, DOT-4, DOT-5 and DOT-5.1 are in use (liquids with the trademark Neva, Tom and Dew correspond to this classification). Which one to use in this car, again decides the manufacturer. It is impossible to use TJ with a class below the tolerance, higher - it makes no sense, because you will have to pay extra for excess properties. Although the residents of mountainous areas and urban "street racers" the transition to DOT-4, perhaps, does not hurt. All these liquids (imported and domestic) are compatible with each other and painted in yellow. An exception is the DOT-5 class. It has a different (silicone) base and, when mixed, precipitates. External difference is a dark red suit.
Fluid change is not particularly difficult. It’s best when the artist has a special installation at hand. This is a reservoir divided in half by a flexible membrane. One part of it is filled with fresh liquid, the other is supplied with compressed air. A set of adapter caps allows you to easily connect to any expansion tank. The wizard can only open and close the bleeders in the required sequence.
Worse, when they manage with improvised means, but even in this case, the workshop should have a special key for fittings. When you see the usual “horn” in the hands of a locksmith, immediately back up - the process threatens to drag on indefinitely. The sequence of actions repeats the well-known “swing-hold” scheme. The problem is that when the pressure is released, the pistons of the main cylinder move deeper than usual, and the sealing cuffs, having moved out of their “hardened” places, can lose their tightness. A further prospect is a replacement or repair followed by … pumping!
And the last one. Before changing the fluid, a conscientious master will diagnose the system. Are the rubber hoses intact, or have their replacement dates approached, are the pistons easy to move, have the sealing rings eaten corrosion, are there any leaks. The elimination of these defects requires depressurization of the system. Why not save some of the client’s money by completing the work “at the same time”?
Just at this time, on our faithful “tag”, the time came to renew the brake fluid, and we decided to check whether it is possible to trust such an important matter to the metropolitan servicemen.
ISLAND OF BAD LUCK
I confess, a sinful deed led the reader astray. Following our advice on choosing an “auto-doctor,” most run the risk of being left with nothing. Actually, there are undoubtedly masters who understand what they are doing. Only we have met such people very rarely, although in raids we try to choose services more decently. But this time they experienced something special …
Shchelkovo highway, twenty minutes from the center. Judging by the abundance of machines, the workshop is popular. The master of time did not waste in vain:
- Have you brought the brake with you? Need DOT-4.
- There is! Bank "Elfa" in the trunk for the third year lying around.
- Call on the lift!
The locksmith immediately set to work. True, he did not find any instruments and appliances - not even an empty bottle, where to drain the working off. However, the artisan was not at all embarrassed. Armed with a “horn”, he began to alternately empty the fittings directly into the atmosphere, abundantly irrigating defenseless anthers, silent blocks and tires with poisonous polyglycol. In addition, he chose an unusual sequence - back-to-front. Meanwhile, in the front-wheel drive VAZ models (including our VAZ 2115) the drive circuit is diagonal and it must be pumped accordingly. We were lucky that air did not get into the main cylinder - this specialist could not drive him out of the system. After releasing about three hundred milliliters of TJ, the locksmith considered the matter finished. No matter how! After all, firstly, the internal volume of the brake system is 550 ml plus one hundred milliliters per pumping. Total - 650. Misfire!
(Of course, the volume of the system depends on the degree of wear of the pads, but this value does not exceed 150 ml.) And secondly, disrupting the sequence, the master provoked the mixing of old and new fluids in the circuit. To get rid of the cocktail, one more hefty portion of fresh product would be required. Although … Who are now interested in the nuances! Money (320 rubles) - at the cash desk and “come again!”. Say thanks - the breech car …
Krasnobogatyrskaya Street, of course, is not the center, but also not a remote outskirts. You can’t say the same about the service, as MTS probably looked like a lagging collective farm. According to the master, our desire to change the brake fluid "for inspection" is worthy of all respect. And it doesn’t matter what. The covert bank of the notorious "Elf" goes with a bang. To pump out the liquid from the compensation tank with a syringe, especially a pear, the master disdained. He simply put one of us behind the wheel and forced to press on the pedal until all the liquid had gone through the slightly open bleed fitting into a carefully placed container. It is a pity that customers do not accrue standard hours - it would be possible to make good money. What happened next, we still could not understand - I just had to remember. The professional took a suitable hose and, putting one end on the fitting, the other lowered into an empty jar about a third of its height. After that, having opened the fitting half a turn, he gave the command to download “to the stop”. Obviously, the proposed technology was not particularly effective. During the “there” stroke, the piston pushed the liquid out of the circuit, but during the reverse stroke (and with the nozzle open, I recall), it sucked in air first, and then (as the drain tank was filled) the exhausted “brake”. The result - 400 ml of spent fluid, 500 rubles for work and … a fair amount of air in both circuits. We do not think that the welcoming owner wanted to harm the guests. He just couldn’t do worse, but better he can’t.
The next technical center in a prestigious place is within easy reach of the main entrance of VDNH. They specialize in foreign cars, but for us, due to the lack of visitors, they made an exception. Alas - the children of high foreign technology have long been divorced from domestic roots. Having completely forgotten about the appointment of a primitive “sorcerer” (a regulator of braking forces), they could not understand for a long time why the liquid is in full swing from the front fittings and hardly drips from the rear ones? The process of cognition ended with ablution in the brake fluid, which finally escaped from the rear axle line. By the way, despite the alien image, the workout was poured on the floor. But maybe the tank with a tube was not for us?
The most common way to avoid mistakes is to do nothing. The master acceptor of a service belonging to one technical assistance service popular in Moscow has learned this rule firmly. And he reacted to the request to replace the brake fluid accordingly: “Who advised you this stupidity ?!” Who, who … While we were looking for a worthy answer, the super specialist was already hiding behind the door. And that’s right: if you don’t know how - don’t take it!