Bleeding air from the hydraulic circuit of the clutch release drive (Opel Astra G)

The hydraulic fluid used as a working fluid in the clutch drive path is toxic and chemically aggressive and destroys the paintwork when in contact with body panels. Before starting the procedure, cover the fenders and front panel of the car with special covers or just old blankets. Bleed the brake system wearing safety glasses. If brake fluid accidentally gets into your eyes, immediately rinse them with plenty of water and seek medical help!

The hydraulic system release drive must be bled every time its components are removed, and also when the fluid level in the reservoir drops so much that air gets into the master cylinder. The bleeding principle is the same as that used to remove air from the brake tract. When bleeding, use only fresh hydraulic fluid of the required grade.

1. The bleeder valve is located where the hydraulic hose is attached on top of the manual transmission housing. On some models, access to the valve may be difficult. Jack up the car and place it on supports.

2. Make sure that the union connections of the clutch hydraulic circuit are tight. Wipe the bleed valve thoroughly.

3. Remove the master cylinder reservoir cap and fill the reservoir with fresh hydraulic fluid, bringing its level to the MAX mark. Replace the cap. Remember that during bleeding the system, to avoid the risk of air being sucked into the tract, the fluid level in the reservoir should not fall below the MIN mark.



[Material was taken from a resource: www.opelbook.ru]

Do not reuse liquid that has been pumped out of the system, or liquid that has been stored for a long time in a loosely closed container!

The main method of pumping - requires the help of an assistant

1. Remove the dust cap and attach the end of a suitable sized plastic hose to the cylinder bleeder valve. Place the other end of the hose in a transparent container partially filled with hydraulic fluid - make sure that the end of the hose is completely immersed in the fluid.



2. Ask the assistant to press the clutch pedal several times to increase the pressure in the tract, then press it and fix it in the lower position. Open the bleeder valve and release the liquid from the cylinder into the drain container. When the outflow of liquid mixed with air bubbles stops, tighten the valve tightly again and allow the assistant to release the pedal.

3. Continue bleeding in the same manner until the fluid coming out of the cylinder is completely free of air bubbles. Constantly carefully monitor the fluid level in the master cylinder reservoir, not allowing it to drop too low, which could result in air getting into the tract and nullifying all efforts made.

Bleeding method using a check valve kit

As the name suggests, the bleeding kit includes a section of hose equipped with a one-way valve. The valve prevents the fluid being pushed back into the system and allows bleeding to be done by one person - do not forget to monitor the fluid level in the master cylinder reservoir (it should not fall below the MIN mark!).

Bleeding using compressed air

1. The spare tire can be used as a source of compressed air - it is necessary to release its inflation pressure first. Follow the instructions included with the kit.

2. When using such a device, you only need to release the bleed valve and wait until air bubbles stop escaping from the tract.

3. The main advantage of this method is that the large reservoir with hydraulic fluid included in the kit prevents air from being sucked into the tract during bleeding.

All methods

1. After bleeding, check the clutch pedal travel - if the previous softness has been completely eliminated, tighten the bleeding valve with the required force, put the protective cap on it and collect traces of spilled fluid with a rag.

2. Check the fluid level in the master cylinder reservoir - make the appropriate adjustments if necessary (see Chapter Routine maintenance).

3. The drained liquid cannot be reused and must be disposed of in accordance with environmental protection requirements.

4. Check the proper functioning of the clutch - if it does not disengage when the pedal is depressed, then not all the air has been removed from the tract and bleeding must be repeated. If a satisfactory result cannot be achieved after several bleedings, the condition of the sealing elements of the union connectors of the hydraulic lines on both cylinders should be checked.