Check of the vacuum brake booster
The vacuum amplifier is designed to provide an additional force applied to the rod of the main brake cylinder. The vacuum in the brake servo is created due to the reduced pressure in the intake manifold.
Servo can not be repaired and replaced in case of failure. If with the engine running in order to achieve a sufficient braking action requires an unusually large force to the pedal, check the vacuum brake servo.
Check of the vacuum amplifier spend in the following order:
- Then 5 - 6 times on the brake pedal with the engine off, to create a vacuum and atmospheric chambers of the vacuum amplifier the identical pressure close to atmospheric (remove the vacuum discharge);
- Hold the brake pedal down, start the engine;
- At serviceable vacuum amplifier the pedal after the engine has to "go forward" and weaken the force of resistance to the leg;
- If the brake pedal is not "go forward", check the tightness of the connecting hose between the inlet channel and the amplifier or the serviceability of the vacuum booster.
The cause of the vacuum amplifier may be a check valve. Use a screwdriver to gently squeeze the valve and blow it in the direction of the arrow, which is stamped on the valve. While blowing air exits from the other side of the valve. If you lean against the embossed arrow on the valve, the air vice-versa should not go to the other side. When installing the valve is pressed into the vacuum brake servo.
The reason for failure of the vacuum brake booster should be sought in the workshop.
Removal and installation of the vacuum amplifier without the ABS system installed
Description for removal and installation of the vacuum amplifier with built-in ABS system is presented in Sec. 15.9.1.
Removal - servo spend in the following order:
- Remove the wire "-" O with AB;
Fig. 328. Partitions compartment AB (indicated by arrows)
- Remove the sound insulation located in the engine compartment of the engine;
- Remove the AB;
- Remove the coolant expansion tank;
- Disconnect the plug connector Multi-display coolant temperature and remove the two screws;
- Unscrew the two screws and remove the right cover partition AB;
- Turn away a bolt and remove the left rear compartment bulkhead AB. Put aside the surge tank;
- Disconnect the electrical connector on the cover of the brake fluid reservoir and remove the reservoir tank cover;
- Using a siphon-pear pump out the brake fluid reservoir and remove the brake master cylinder;
- Disconnect the vacuum hose going to the vacuum brake booster;
- Remove the bottom casing of the instrument panel on the driver side;
Fig. 329. Removing the thrust rod of the vacuum brake booster from the brake pedal 1 - a spring collar; 2 - the pin
- Remove the spring clamp 1 (Fig. 329),
then remove the pin 2, and disconnect the brake pedal pushrod vacuum brake booster;
- Remove the four nuts of the vacuum brake booster and remove it.
The installation of the vacuum amplifier spend in reverse order, follow these steps:
- Tighten the four servo mounting nuts to 40 N ?· m;
- Set the brake master cylinder (see. P. 15.5.1);
- After installation, restore the level of liquid in a tank and pump over hydraulic drive system.