Jeep Grand Cherokee

1993-1999 of release

Repair and car operation

General information

Cars considered in this Management are equipped with hydraulic lobbies and back brake mechanisms. Forward wheels are equipped with disk brake mechanisms of ventilated type (with ventilated disks), back - drum-type mechanisms (all models 1993 and some of 1994 вып.) or disk, continuous type (with continuous disks) (some of models 1994 and all 1995 вып.). Both forward, and back disk brake mechanisms are equipped with devices of automatic compensation of wear of blocks while drum-type mechanisms are supplied with the devices of self-regulation put in action at braking of the car moving by a backing.

Hydraulic system

The hydraulic system is divided into two independent contours. The main cylinder is equipped with two tanks and in case of leak or refusal of one of contours, another remains on former efficient. A signal of refusal of any of contours or air hits in them is fire of the control lamp which inclusion is carried out by replacement of the piston of a part combined valve of the differential switch of pressure from its normal "equilibrium" situation.

Assembly of the main brake cylinder with the tank

On all models it is used special, the ABS type, the main brake cylinder. The ABS block by a principle of action is very close to the cylinder of usual type: When squeezing a brake pedal the pusher connecting a pedal to the amplifier of brakes, moves forward. Here the effort enclosed to a pedal of a brake, is increased and told to pistons in the ABS cylinder that leads to increase of hydraulic pressure in contours. The main difference of the ABS cylinder from the cylinder of usual type is application instead of cuffs on its pistons of special valves.

In view of uniqueness of the design the main brake ABS cylinder of type is not subject to repair not only in house conditions, but also even strengths of specialists of car-care center. In default the block should be replaced assembled. Main brake cylinders of models 1993 and 1994 of вып. are equipped with two jellied covers; on cylinders of models of 1995 вып. there is only one cover. Blocks are not interchangeable. The unique replaceable components of assembly of the main cylinder are the tank, its adjusting rubber plugs and connecting hoses.

The combined valve regulator

The combined valve established on the main brake cylinder, carries out some functions:

As the measuring valve (limiter), it limits the effort developed by forward brake mechanisms until pressure in a forward contour will not reach previously the established value and there will be no activation of back brake mechanisms.

The regulator provides control of final pressure of a back brake contour after achievement by inlet pressure previously the established value that allows to avoid premature blocking of back wheels at high brake loadings.

Besides, the design of the combined valve allows to support a total pressure in one of brake contours in case of failure of the second. Included in valve structure the differential alarm sensor switch continuously compares the pressure developed in forward and back contours. In default in system on the dashboard the alarm lamp of red color lights up. The lamp continues to remain included until malfunction will not be eliminated.

Amplifier of brakes

Dvukhdiafragmenny, operated by vacuum and established on a partition of an impellent compartment, the amplifier of brakes in the work uses a difference between pressure in the inlet pipeline and environment, providing additional effort to brake mechanisms operated by hydraulics.

Blocks of amplifiers of brakes of models 1993 and 1994 of вып. are equipped with the sensor of a course of a brake pedal of ABS system. Since 1995 these sensors ceased to be established that explains a certain difference of their amplifiers from the blocks which are applying on earlier models. It is necessary to remember that blocks of different types are not interchangeable.

Parking brake

The parking brake consists of a control lever established between forward seats of the car, the driving cables connecting the lever to back brake mechanisms, the device of balancing of a tension of cables of a drive of mechanisms of each of back wheels and brake boots of the parking brake. On all models 1993 and 1994 of вып., the back wheels equipped with drum-type brake mechanisms, the parking brake influences boots actually mechanisms of wheels. On models of 1994 вып., the back wheels equipped with disk brake mechanisms and all models of 1995 вып. small boots of the parking brake are placed in naves of disks of back brake mechanisms (naves are used thus as drums of the parking brake).

Service

After end of any of the procedures, demanding dismantling of brake system any of parts before starting car operation without fail make its trial runs for check of serviceability of functioning of brakes and efficiency of braking. Check of brakes make on a pure, dry and equal paving. Default of this requirement can does results of check doubtful.

Check functioning of brakes at various speeds of movement of the car both at weak, and at strong squeezing of a brake pedal. Braking of a vehicle should be made evenly, without breakthroughs and its withdrawals aside. Avoid blocking of brakes as movement the yuzy conducts to wear of protectors and reduces controllability of the car.

It is necessary to refer to the factors influencing efficiency of braking of the car also its loading, a condition of tires and correctness of adjustment of corners of installation of forward wheels.