CLUB OF CAR FANS
/WORKSHOP
AGE OF PROBLEMS
BRAKES TO DO NOT FAILURE
TEXT / ANATOLIY WAYSMAN
No offense will be said: the recommendations of some factory specialists in repair and maintenance evoke the words of the classic - "… they are terribly far from the people." When we, the repairmen, need to unscrew something on the old machine, it turns out, relying on the factory instructions is more expensive for ourselves: either nothing will come of it, or the owner will pay ten times …
SURPRISES OF BRAKES
Their main enemy (after the owner, naturally!) Is corrosion. Example: you traveled comfortably for several years, changed the front pads more than once, and laughed at the idiots who broke the eyes of the cylinders … And suddenly your guiding fingers - for no apparent reason! - grabbed so that you can not pull it out. Fuck with a heavy hammer, but stronger? But that's how the eyes break! In such clients I do not feel a lack.
We constantly replace working cylinders. They turn sour easily: the pistons move tighter, the useful force drops, and the brake also disappears: he took his foot off the pedal and the block was pressed against the disc. Hence the wild wear and tear - especially for the “deaf” client who does not hear that the block has worn off to metal. To reanimate, “develop” such cylinders is a thankless task. Soon, everything will happen again, or even the cuff will leak.
… But then the client arrived with the usual complaint: the “six” pulls strongly to the left when braking. The reason is clear - the right front wheel does not slow down, the cylinders are soured. But when we took off the wheel, the result surprised: the cylinders are in order, the pistons are pressed to the pads as they should … Why does the brake not work?
We are boring people, we do not believe in miracles. Therefore, we carefully looked at the pads, felt. And those … sat in the grooves of the caliper, as if welded - and the pistons (with their strength!) Could not press the pads to the disk. Only then the owner remembered that from a month ago he had pads changed, and they did not climb into the grooves - and the master hammered them. You do not believe? There are enough such craftsmen!
The brake mechanism is very hot - and therefore rusts even faster. Do pads sit today without gaps? Tomorrow they will stop braking altogether. It is not for nothing that we check each before installing whether it fits well into the groove. Often you have to file, deburr, remove dirt and scale from the grooves.
"GIFT" FROM BOLT
Suppose you were struck by a common misfortune: the front brake slave cylinder “ran out”. Must be replaced. But as? According to the official method, it is necessary to remove the caliper assembly, and then dismantle the cylinders on a workbench with a vise. Easy and simple, especially on a brand new car. And when she is already at the “PEAK” age, an attempt to unscrew a pair of bolts securing the caliper to the bracket often ends with a characteristic “bang!”: The bolt is cut off. Even if it’s alone, then this is an adventure worthy of the “Camel Trophy”: the support cannot be removed - it will not let the end of the broken-off bolt. What do we do?
There are two ways out. If the disk is very worn out and it is time to change it, they take up the hammer and the “grinder”. Hacking cast iron is not so difficult. Having got rid of a disk, the support gains freedom.
And if there is no reason to break the disk, we act differently. Having separated the pads (photo 1), we extract them. Now, moving the caliper, twisting it, tapping it, we remove the broken-off end of the bolt from the hole (photo 2).
The operation, frankly, is not easy. Depending on how the end of a particular bolt protrudes, it is sometimes very difficult to remove the caliper. It happens that you even have to deform the bracket, otherwise the caliper will not be released.
By the way, here I want to recall two important points. Firstly, if the pistons stick in the cylinders, then they can only be drowned with considerable force. Then do not try to lean by mounting on the edge of the disk. Even “slightly” bent, it will provide strong shaking with every braking.
Secondly, do not spoil with fire. Yes, any assembly can be disassembled by heating with a blowtorch or a torch! But in our workshop “hot” technologies are not held in high esteem: do we not know how easy the car breaks out and how difficult it is to extinguish. You can’t cope in the first seconds - and you will save the entire service along with the staff. But there are exceptions to every rule. In this case, the main thing is a reasonable approach, caution.
That is why when replacing the brake cylinders, we generally do not remove the caliper, so as not to risk it. We make it easier. Having drowned, as far as possible, the fixing pin, we hit the cylinder with a hammer through the mandrel (photos 3 and 4 show the direction of the blows). Caliper - the part is durable, but does not suffer.
The operation is simple, it takes a little time. And now the machine is working, the customer is satisfied. This was the task!
Breeding pads, do not load the disk!
… so that the caliper comes off the broken bolt.