DIY Lacetti front caliper repair

The article will discuss how the brake caliper works and how to perform caliper repair do it yourself at home.

When the driver presses the brake pedal, the pads are pressed against the discs and thus the car stops. But unfortunately, they have not yet come up with mechanisms that could retract the brake pads to their original position. They just stop pressing tightly against the discs. Often, after long-term operation, the brake mechanism acquires some malfunctions, which significantly affects the rapid or uneven wear of brake pads and discs, increased noise and an unpleasant odor. The pads overheat and lose their grip at the same time. In short, the vehicle's braking system becomes ineffective.

In fact, there are not so many reasons why such malfunctions are possible. These are either damaged guides along which the caliper moves, or dirt on the working surface that interferes with the free movement of the pads.

Well, or the caliper itself. The last option will be discussed in this material:

-Small amendment: there is still a part in the caliper that contributes to the return movement of the piston after the loss of pressure - this is the cuff. On the one hand, it provides tightness, on the other, it is a kind of spring. Square in cross-section, when the piston moves, it deforms, and then tends to take the form of rest, along the way slightly recessed the piston into the body.

Over time, the elasticity of the cuff is lost, the pads remain pressed against the discs, increased friction, overheating and all other delights. This is not always obvious. How can you troubleshoot?

First of all, the suspended wheel should spin freely, even immediately after pressing and releasing the brake pedal.

Brake discs must not show signs of overheating

outer and inner pads should not have a difference in thickness

brake caliper piston should be easily recessed into the housing.

If there is cause for concern, we start looking for a problem. Most often it occurs due to a damaged anther.

but even if outwardly intact, look under it

the piston surface must be perfectly flat, without any traces of rust or dirt.

VAG provides a repair kit consisting of rubber bands, there are also a bunch of analogues from third-party manufacturers

but there is no piston on sale. However, this is not a problem at all, you can safely use non-original pistons available on the free sale for cars of previous generations.

And now about the repair procedure itself:

-jump the car and unscrew the wheel, turn the steering wheel to the extreme position

-remove the retaining spring

- thoroughly clean the surface near the brake hose mount

- rinse with some kind of cleaner, blow with air

-in order not to lose the brake fluid level, we pinch the brake hose

- unscrew the hollow bolt securing the hose,

- so that the dirt does not get inside, and the liquid does not flood everything around, put a simple bolt with a thread 10 * 1.5 into the hole

-remove the protective caps on the guides

-Unscrew the guides with a 7 mm hexagon.

-it is necessary to slightly drown the piston, for that, using a thick screwdriver, we move the body away from the disk

-remove the caliper, helping ourselves with a screwdriver (screwdrivers)

- one block can remain in the bracket, one is fixed with a spring to the caliper

—stopping support in hand. Remove the cover with a flat screwdriver

- miracles, but even with external well-being, moisture could be inside

-the piston can be removed from the body in three ways:

- without still disconnecting the caliper from the hose, remove it from the disc, and press the brake pedal until the piston falls out. And immediately pinch the hose.

- squeeze the body in a vice, and pull the piston with large "crocodiles", simultaneously making circular movements

- but the easiest way is to remove it with air. However, do not forget to provide support for the safety of your own body parts.

- having drained the remaining brake fluid, remove the old cuff

- it is necessary to thoroughly clean the seating surface of the protective cover

-and also grooves for the cuff

-Before reassembly, it is necessary to flush again (ELSA recommends alcohol, but not inside) and blow with air.

- with clean (!) hands we put a new cuff

-Slightly lubricate it with fresh brake fluid

-a bit t. spill on the piston surface (the same ELSA provides a special paste for this)

- we put the piston in the body strictly vertically, and slightly shaking it, with the effort of our fingers, we press it

-Drowning almost to the middle, put on a protective cover

- making sure that the elastic is not jammed anywhere, press the cover onto the case. A wire ring is welded into it, a special mandrel is provided for an even fit by VAG

-but you can do without it, the main thing is uniform effort

- drown the piston completely, and then push it out with the help of air, and make sure that the boot is flat, not twisted or torn anywhere

- re-sink the piston completely, and you can start assembling. However, since we have come to the repair and maintenance of brakes, everything must be done correctly. So - we unscrew the caliper brackets

-and thoroughly clean all surfaces on which the pads move

-make sure that the thread into which the guides are screwed is not damaged

* weak point on VW of the latest generation. Often, when unscrewing the guide, dirt and rust formed on the protruding part pull out the threads behind them.

-screw the bracket into place (before reuse, clean the bolts and tighten them with a torque of 190Nm ),

put the block on and make sure that it does not get stuck anywhere

-clean the guides from dirt. If there are traces of rust, it is better to replace them altogether.

-insert the inner block into the piston with a spring, put the caliper on the bracket, bait the guides with your fingers (!)

be sure to make sure that the bolt goes along the thread, and only then tighten (30 Nm)

-we put on the caps, so as not to forget later, insert the spring

-the brake hose is attached to brake caliper hollow bolt, and sealed with two rings.

- we can safely call them disposable.

And they are removed only with the help of a tool

-but at the same time it is not possible to find them in ETKA as a separate part. You can safely put rings from a similar assembly used in domestic cars. Unless, before installing, slightly move back and forth on a fine skin

- Before assembly, blow out the fitting

-and clean the mating plane on the hose

-Unscrew the bleed fitting and release the brake hose

- usually, after such work, there is no need to pump the circuit, it is enough to wait until the liquid flows from the fitting, evenly and without bubbles

-for ecology lovers, you can hang a bottle and control the air through a transparent hose

- tighten the shooter (30Nm), get behind the wheel and reduce the pads with a few strokes of the pedal.

-wash off the remaining brake fluid and others and traces of activity

- especially pay attention to the CV joint boot, ball joint and steering tip covers

If these are not observed, we fasten the wheel, lower the jack. Open the hood and check the brake fluid level in the reservoir. Top up if necessary.

Make a test drive. If the pedal fails when pressed for the first time, and after a couple of strokes it becomes higher, repeat the procedure for removing air.

There is also a possibility that due to the different elasticity of the cuffs in the old and worn caliper there will be a difference in the speed of the brakes. Therefore, it is advisable to carry out the bulkhead on both sides at once.

Well, now you can rejoice in the serviceable brakes.
Thus, now you have learned how to execute repair of front and rear brake caliper

EVERYTHING WITH OWN HANDS. FROM 95 TO 92, WINDOWS, DRL, STOP SIGNALS, SOUND SIGNAL, DMRV AND DAD, HOW TO SAVE PETROL AND MORE ...

25.04.2017
... ... Watch the video Calipers Rattling while. I will write the article a little later, otherwise it’s too late today, and tomorrow I’ll get up early for work. If something is not clear - write in the comments, then I will know better what to pay more attention to.

... ... There was a time and decided to finish the article.
The caliper bracket on our machine is held on two guides. The same system is installed on most modern cars, but on these cars the designers have provided holding springs for the caliper bracket so that when driving through irregularities on the road it does not rattle, shake and break the guides. Apparently, our designers were sure that what is needed in Russia is expensive - like a map. And these caliper holding springs, in principle, we do not need, and will only increase the weight of the car. In general, well done - as always.

... ... I removed the guides - there is no production. I stuffed special grease for the calipers - on our roads it was enough for a couple of days, and again they thundered. It looks like the Lacetti needs to be driven only along the Moscow Ring Road. And you do not need to smear - and will not break. But we don't have such roads, so I decided to think about what can be done in a simple and tasteful way. I read it on the Internet, they write that springs are being sold, but to install them, you need to drill the caliper itself, and insert the ends of the spring into these holes. Calipers rattle - this is not the main problem. The bracket itself is not light, and under its own weight from shaking it breaks the guides and their nests. And the caliper is not a cheap thing. In general, I sat, smoked, thought to my nose and decided to do this:

28.01.2018
I still go and everything is fine. Over the years, I have developed a habit - if I am driving along the highway and there is a stop, then I always check all the wheels for heating. This way problems can be detected in a timely manner. In general, I am satisfied and forgot what it is - rattling calipers.

Can be shared with friends

It seems to me that the load on the guides is increasing, and if someone has already begun to bite the cylinder, then it can also play a cruel joke. there is a big problem with our cars in terms of rear brake calipers. I myself recently got to such a repair. Bites on cylinders and pads do not squeeze out. I propose to come up with something with guides, according to how exactly the fork hangs in them

Guides and breaks from shaking, because we do not have retaining springs, like on other cars. And the best solution is a fixed caliper with two cylinders on either side.

I read a lot about this problem. I already run 270 thousand km. There is a tangible development of guides. But I never heard a knock. And there were never any complaints about the brakes. ?? Assembling Korea.

Chevrolet Lacetti Replacement of protective covers and o-rings of the pistons of the front and rear wheels

We replace the protective cover of the piston if it is damaged - cracks, ruptures of rubber or loss of elasticity of the cover.
The O-ring is replaced if there are traces of brake fluid leakage in the brake mechanism.
The replacement of the cover and the O-ring is shown on the front wheel brake cylinder. The boot and the O-ring on the rear wheel brake cylinder are replaced in the same way.
Remove the front wheel.
Disconnect the lower tip of the brake hose from the caliper (see Replacing the front wheel brake hose).
Remove the brake pads (see Replacing the brake pads of the front wheels).

With a spanner wrench "14" we unscrew the upper bolt of the caliper fastening to the guide pin ...

We remove the piston from the caliper.
To remove the piston, you can blow compressed air from the tire pump through a hole in the caliper.

We remove the protective cover from the caliper.

Pry the O-ring with a screwdriver ...

… And remove the ring from the caliper.
Install a new O-ring. Insert the new protective cover into the groove of the caliper.
We apply brake fluid to the working surface of the sealing ring and the surface of the piston. To install the piston, we clamp the caliper in a vice with soft metal jaw pads. In order to put a protective cover on the piston, we connect the hose of the tire pump or compressor to the caliper bore.
We supply air to the cylinder and bring the bottom of the piston to the edge of the cover, centering it relative to the cover.

Under the influence of air pressure, the cover expands and is put on the piston, which is inserted into the cylinder.
In the absence of a pump, to put the cover on the piston, an assistant will be required, who must lift the cover (inserted into the caliper groove) by the edge and stretch it so that the piston can be inserted inside.
Putting on the cover, we center the piston ...

… And, pressing on it with a wooden block, we sink the piston into the caliper.
We assemble the brake mechanism in reverse order.
We pump the brake system hydraulic drive (see. Bleeding the brake system hydraulic drives).

Brakes are a very important element of any car, because your safety depends on their performance. The main load on any car is borne by the front part, as we know there disc brakes. After a long mileage, already from 60,000 kilometers and more, the braking efficiency begins to fall, this may be due to improper operation of the brake caliper, sometimes you can even catch a "wedge". However, the device is quite simple and can be repaired by hand. I think this article will be useful to you, at the end there will be a detailed video ...

CONTENTS OF THE ARTICLE

To begin with, I will say that the front wheel can simply jam, by analogy as in this article, it just stops spinning! Guys, this is very dangerous, at speed it can lead to an accident. Therefore, the caliper must be diagnosed correctly and on time. However, to begin with, a little about the structure.

There will be a separate article about the caliper, but now I want to show on my "fingers" what moving parts there are that suffer in the first place. This is a fairly simple device, it has only two working elements - guides and pistons.

They are the culprits of the whole "celebration", if they fail, then the work is disrupted. However, the structure of the piston is now quite strong, physical leakage, when you broke, say, the brake hose, is now a rare phenomenon. And therefore the caliper breaks down due to acidification of the pistons and guides, but about that a little lower.

If the operation of this unit is disrupted, then it turns out that there is an uneven wear of the brake pads. You just need to pull them out and look at them, if they work correctly, they should have approximately the same wear (plus or minus 10%). If the rear, for example, is thicker than the front, it turns out that the caliper is not working properly! The brake disc is also worth looking at - wear should be even. If the wear of the pads is uneven, and it is pronounced, for example, the outer one is much more worn out than the inner one, you urgently need to either change or repair the caliper and not wait until it jam.

Such uneven wear speaks only of the rim - the pistons strongly press on one pad (there is maximum wear), and the second does not seem to be involved at all.

The reasons, as always, are commonplace, they are "souring" or "coking" of the brake pistons or guides. This can happen both due to improper maintenance and due to a banal breakdown.

1) Improper service. Often, LITOL or graphite grease is stuffed on the guides in the garages of folk craftsmen, which leads to the swelling of the anther of the guide, and later it simply "sours".

2) This is a banal anther breakthrough. Moisture begins to flow onto the guide, which sooner or later will corrode it and lead to acidification.

3) The next reason lies in the piston itself. Its body can also suffer from a ruptured anther, water gets in.

4) Either from poor quality brake fluid.It is hydroscopic, and therefore, over time, a lot of water accumulates in it, if it is not replaced, it begins to corrode the piston from the inside, which also leads to acidification.

Well, now let's go directly to the repair of the caliper. Let's start with the simplest.

Often, the guides are a kind of bolts that are screwed into special lugs of the body. If they show foci of corrosion that can no longer be removed, then they just need to be replaced.

We unscrew it from the mount (ear) and insert a new guide, a very simple replacement. After that, you need to use only the correct lubricant (usually comes in the kit), and it is also important not to forget to put on the anthers, we immediately check them for leaks, there should be no breaks and cracks. Now I propose to move on to the pistons.

Here the task is more difficult, because they are located inside the caliper body and repair is not so easy. I want to note right away - there are times when the piston gets wedged in the body, and it does not move at all! There can be two actions here:

1) Try to revive this caliper, put it "soak", say, in gasoline or silicone grease. Then carefully try to pull the piston out of the housing.

2) Buy a corny new caliper. Sometimes it jams very firmly, breaking the case; repairs will not help here.

If the pistons are still running, the first difficulty concerns pulling them out of the body. To do this, the service station uses compressed air, which is fed into the brake fluid hole. Thus, the piston simply flies out, if you are doing repairs in the garage, then you need to "squeeze out" with the help of brake fluid, simply without disconnecting them from the general system. Do not worry that the "brake" will leak, you still need to change it after repair.

Now we examine the case. If there are traces of bending, rust, or mechanical damage, then it definitely needs to be changed, the repair will not be justified here. To do this, we purchase a repair kit, with rubber seals and new pistons, it is important to replace that it must have a special lubricant, usually for both the guides and pistons! IT IS IMPORTANT!

Without it, there will be no point in repairing, because how can you break new seals.

Now I will list the points:

1) We take out the old rubber bands and seals.

3) We clean the case, both outside and inside.

4) Then, applying a new lubricant, we process all the attachment points.

5) Install the gum seals

6) Install the pistons, also pre-lubricated.

After these manipulations, we collect the caliper. The repair is finished, it can be installed on the car. Do not forget to change the brake fluid and then bleed the system.

Now I want to provide you with a detailed repair video, described in more detail.