To set the car in motion, it is necessary to transmit torque from the engine to the box. The clutch is responsible for this. It is this unit that transmits torque through certain gears to the wheels. The main function of the clutch is to temporarily disconnect the power unit from the gearbox. The mechanism is also responsible for the smooth start of the transmission links when the engine is started.
Using the clutch, it is possible to prevent a sharp change in load, which ensures a smooth start of the car from a place. The clutch also protects the entire transmission from loads of inertial moments, which arise as a result of a sharp slowdown in the rotation of the crankshaft on the running engine at the moment when the driver changes gear.
On Gazelle vehicles, a hydraulic clutch system is installed. She gained wide popularity on many models of modern cars. The design of the hydraulic mechanism is based on the clutch master cylinder.
Gazelle "Business" is also equipped with it. The main task that the cylinder solves is the transmission of pulses from the pedal to the working element of the system. Using this unit, the start of the machine is ensured. Also, the mechanism makes it possible to shift up and down gears.
Below we will consider the device of the clutch master cylinder. "Gazelle" is a commercial vehicle, so it periodically requires maintenance. What malfunctions happen to the clutch, how to repair, maintain and, if necessary, change this unit? Let's talk about everything in order.
How is the hydraulic drive "Gazelle"
It consists of a small number of parts and assemblies. So, in the system there is a reservoir of the clutch master cylinder. The Gazelle has been equipped with it since 1995. The reservoir contains brake fluid, which works in the drive. The assembly also includes a master and slave cylinder, tubes, hoses and nozzles. The system also uses a return spring.
The principle of operation of the hydraulic actuator
If you do not go into details of how the clutch master cylinder is arranged, GAZelle works as follows. When the car driver presses the pedal, this force is transmitted to the main drive via the rod. Here it is perceived and passes through a network of tubes to the working cylinder. The latter, by means of the clutch fork and release bearing, disables or connects the engine to the transmission.
Hydraulic drive unit
Among the main nodes that are included in the design of the element, one can distinguish a pusher. With it, the pedal communicates with the mechanism. It is also the cylinder itself, the piston, the plugs and the return spring.
What is the clutch master cylinder? The Gazelle is equipped with a unit with two halves, which are separated by a special partition. The upper part is designed for working fluid, which in the process comes from the tank. In the same place, in the upper part, a certain supply of liquid is stored. If the clutch and hydraulic drive are normally adjusted, then its level should be no less than three quarters of the volume.
In the lower half is the working area. In the usual initial state, the cylinder piston is pressed by a spring against the wall dividing the cylinder into two zones. There is a gap between the piston and the pusher. Due to it, the liquid enters the working part. When the driver presses the pedal, the pusher moves and closes the gap. Fluid can no longer flow from the upper to the lower zone. The piston moves and the force is transmitted from the driver’s foot directly to the working cylinder.
Due to the fact that the dimensions of the piston and the outlet are different, the hole increases. That’s enough for the clutch to work. This design facilitates the effort that rests on the pedal. This force is quite enough to disconnect the engine from the box. When the pedal is released, a spring will act on the piston. Also, due to the pressure in the hydraulic system, the pedal will be able to return to its original starting position. The pusher will go into the same position. Due to this, the liquid will again freely penetrate into the lower capacity of the cylinder.
When clutch master cylinder repairs are required
The gazelle may require repair if fluid leaks or air enters the system. Even though the design of the cylinder is simple, problems also occur with it. There are several faults. Details of each of them are provided below.
Repair may be necessary if a lack of working fluid is detected. Causes can be cliffs or damage to the cuff of the cylinder, violation of the tightness of the joints. In this case, it is recommended to make sure that the level in the expansion tank is sufficient. If there is little fluid, then it is added. Then periodically check the level during routine maintenance or technical inspection. Sometimes a simple topping up of the working fluid may not help. Then a thorough inspection is carried out, the place of leakage is identified and then they are tight. In this case, you can not repair, but simply change the clutch master cylinder to the Gazelle.
Another common problem is the air in the system. Such a problem can lead to complete inoperability of the node. The clutch will not be completely squeezed out, and the operation of the pedal will be accompanied by a characteristic crunch or vibration on the gearshift lever. Among the reasons why air enters the system and directly into the cylinders, various destruction of the hoses and the natural wear of the parts can be distinguished. Do not exclude fluid leakage in places where sections of the hydraulic drive are interconnected. How is the clutch master cylinder repaired in this case? "Gazelle" is placed on a flat surface, damaged hoses are replaced, followed by pumping the system.
Pumping fluid through the cylinder
There is also one more malfunction - in this case, the cylinder can pump the working fluid through itself. The cause of the malfunction is the cuff, which is most likely damaged. Perhaps there is a development due to natural piston wear.
All these malfunctions can be fixed using the clutch master cylinder repair kit. "Gazelle" in this case can be quickly returned to working condition. The kit includes all the elements that often fail. The process of replacing the cuff and other parts is not particularly difficult for the drivers of these cars.
If the first signs of cylinder malfunctions are observed, it is necessary to carry out diagnostics and maintenance of the clutch system. This will help to avoid the need to completely replace the cylinder.
Partial repair of the master cylinder with a repair kit
With it, you can avoid the need to completely replace the assembly. The repair kit consists of the following parts:
- Protective cap.
- Retaining ring.
- Return spring.
- Cuff of the main cylinder of coupling "Gazelle".
To disassemble the cylinder completely, they look for a special cork on it. It must be unscrewed. During assembly, a gasket seal must be installed under this plug.
Dismantling and defetting
The first step is to remove and disassemble the cylinder. You can find it in the left rear corner under the hood of the car.
Then, after the assembly is disassembled, all components are washed with brake fluid - do not use aggressive solvents for this. Then the cylinder is inspected for scoring. Check the condition of the mirror and the stem. If slight corrosion or scuffing is noticeable, these defects can be repaired with a fine emery. But such damage may indicate a large gap between the cylinder and the piston.
Next, replace the worn parts that are provided in the repair kit. Before assembling the clutch master cylinder, the Gazelle must be put on the hand brake. Every part must be lubricated with brake fluid. A little grease is applied to the surface of the piston that will be in contact with the plunger . Next, the cylinder is assembled, installed in its place and pumped.
Clutch master cylinder replacement
Gazelle requires this operation for the same reasons as in the previous case. These are leaks, natural wear and tear, malfunction of the clutch mechanism. As already noted, this cylinder is located on the left rear corner under the hood of the car.
Before the replacement itself is performed, it is necessary to drain the brake fluid from the system. To do this, the hose is connected to a special fitting. The latter is located on the working cylinder.
Next, disconnect the clutch pedal from the cylinder. To conduct this operation, remove the part of the dashboard located under the steering wheel. Then remove the locking bracket, which can be found on the pedals and pull the pin on the cylinder pusher.
When the fluid supply pipe from the master cylinder is disconnected, you can begin to unscrew the two nuts that hold the clutch master cylinder itself. "Gazelle-3302" continues to stand on the hand brake. After the nuts are unscrewed, the cylinder can be removed and a new one installed in its place. The installation process is performed in the reverse order. After assembling the system, it is necessary to pump the drive.
How to remove air?
After any repairs to the hydraulic part of the clutch, the system must be pumped. For this, the liquid is poured into the tank literally to the brim, and the fitting must be turned off until it stops. Next, press the pedal several times. This is done so that the brake fluid gets into all the tubes. Then the pedal is fixed. Then tighten the fitting and again depress the pedal several times, and then fix it. Next, they put a tube on the fitting. She is dipped in a bottle of liquid. The union is unscrewed to bleed air. All these steps must be repeated until there is absolutely no air left in the system.
If necessary, add fluid to the tank. Its replacement in the clutch lines should be carried out at least once every 2 years. The brake fluid is hygroscopic. This means that corrosion can form inside the system.
After being repaired or replaced with a new clutch master cylinder, the Gazelle requires pedal adjustment. This is a simple process. A ruler is needed for this operation, but the first step is to diagnose it. If the pedal fails when trying to start moving on the car, various sounds are heard during the shift, shocks and jerks are observed during movement, you must start the engine, release the clutch slowly and try to move smoothly. If the car is in no hurry to get under way, then this indicates that the pedal is set incorrectly. Its course is greater than the norm. Next, using a ruler, measure the distance from the floor to the pedals. It should be no more than 14-16 cm. If it is higher, then the pedal must be adjusted. To do this, a bolt with a lock nut should be found under the hood. It is located where the cable ends. The nut turns up. This achieves the desired pedal stroke. To increase the stroke, the nut must be tightened. If the stroke needs to be reduced, it is unscrewed. After adjustment, check the pedal again. Re-measure the distance with a ruler. Setup continues until the desired result is reached.