A rusty coating on the brake disc. What to do?

If the rust has remained on the brake disc for a long time, it indicates that the brake system is not functioning properly. This situation is undesirable, because it can affect the length (orad distance or travel distance) of the road needed to stop the vehicle. So how to deal with this type of problem or situation?

Rust on the brake disc – as dangerous as natural

The appearance of rust on the brake disc is a natural phenomenon, the intensification of which can be observed even after rainfall, which is associated with an increase in air humidity. However, this is not a major problem, because the rusty coating should disappear after the first braking. In some cases this is not the case, which in practice means insufficient friction between the pads and the brake disc. So what can be the cause for this?

Check the condition of the brake fluid

It is worth starting the diagnosis with checking the level and condition of the brake fluid. This is characterized by high hygroscopicity ( The definition of hygroscopic is the property of absorbing moisture from the air), which means that it has the ability to absorb water, which weakens its properties. The used brake fluid will make it more difficult to transfer the force generated by the pump to the pistons setting the clamp in motion. It is worth carrying out an exchange of the described operating liquid every two years, and a special tester, which costs about NGN 3,000, is necessary to examine its degree of wear. The purchase of brake fluid, on the other hand, costs NGN 2,500 TO NGN 3,000 per 1 liter of brand liquid from producers such as Bosch or ATE.

Disrupted work of the clamp – guides

If the problem of the rusty coating affects only one brake disc, then it is very likely that the cause lies in the clamps. Due to the high temperature and impurities, they can be baked. In this situation, there is an uneven wear of the braking system components, which is manifested by the appearance of a rusty coating.

In order to eliminate the problem, it is worth taking a regeneration of the clamp, which amounts to replacing two key elements. The first of them are guides , and thus steel pins, on which the clamp moves. Over time, they corrode, which significantly hinders pressing the blocks to the target. Replacing the mentioned chains is, thankfully, not complicated, and the repair kit of one of the recommended brands, such as Frenkit or Febest , will cost no more than  NGN 5,000 depending on car make and models

Disrupted clamping operation – pistons

The problem of grating also often affects the piston, so the subsequent elements responsible for the deflection of the brake caliper. The cause, through which they fail, is analogous to the case of guide rails. Due to high temperatures and mechanical damage, sealants and grease are used, which opens the way to rust. Strong pitting makes it difficult to operate the pistons , as a result of which the blocks are not evenly pressed, and on the surface of the disc appears disturbing rusty coating. If the degree of wear of the pistons is really significant, they should be replaced with a set of sealants through which attract dirt. The purchase of a repair kit is an expensive depending on the car model.The repair will require the removal of the clamps and their dismantling for the first part. When disassembling the plungers, a useful accessory will prove to be a squeeze set, which costs about a lot but available by good service outlets.

Measurement of the pressure in the brake system

The pressure gauge is a device that is very useful in diagnosing brake system problems. Although pump failures or damage to the cables happen quite rarely, it is worth checking the work of these components in order to be sure about correct operation of the terminals. The method to check them out is quite simple. It is enough to equip yourself with a pressure gauge and connect it to the end of the brake pipe located at the given clamp. After pressing the brake pedal several times, most manometers should indicate the highest value on the scale, because the correct pressure in the system is high and exceeds 5 megapascals, so 50 bars. Otherwise, take a closer look at the condition of the pump and wires.

Although the rusty coating on the brake disc does not bind well, it is usually not difficult to get rid of the problem. The main culprits are the clamp guides and pistons, which are responsible for the effective pressure of the pads to the target. The most rare reasons are pump failures or significant brake fluid leaks.

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