Pic. 9.12. Brake pipes of the pressure control valve in the brake system (pickup models) - view from above
1. To the right rear brake; 2. To the left rear brake; 3. From the master cylinder (primary circuit); 4. From the master cylinder (secondary circuit).
Note: Before starting work, see note, given at the beginning Chapter 9.
Note: If the valve is suspected to be defective, have a Skoda dealer check its adjustment first (see previous chapter).
Removing
1. Minimize fluid loss. To do this, remove the cover of the main cylinder feed tank and tighten it again by placing a piece of polyethylene under the cover (do not damage the level sensor). This will give an airtight seal and prevent liquid from spilling. Alternatively, plug each metal brake pipe immediately after separating it from the valve (see chapter 10). In addition, it is necessary to plug the openings of the valve itself; work very carefully to prevent foreign particles from entering the system.
2. Loosen the connecting nuts of the metal brake pipes; mark the connections carefully before separating any of the tubes. Remove the valve mounting bolts and unhook the valve spring from the rear suspension torsion beam.
3. Turn off connecting nuts and separate brake tubes from the valve. Try to keep fluid loss to a minimum and wash spilled fluid from adjacent components as soon as possible. Remove the valve.
Bulkhead
4. Don't try to bust or «repair» this component; replace it if it is defective.
Installation
5. Install in the reverse order of removal paying attention to the following:
- a) Tighten the couplers securely, then tighten the valve mounting bolts to the specified torque specifications.
- b) Attach the valve spring to the rear suspension torsion bar. Having parked the car on a flat horizontal area and loaded it to its nominal weight (75 kg on the driver's seat), make sure the length of the spring «A» (pic. 9.13) is 105.00±0.05 mm. If adjustment is necessary, loosen the locknut and turn the adjusting nut in the desired direction until the correct spring tension is achieved (see photo). Then swing the rear suspension and check the length of the spring again. Tighten locknut securely.
- c) Bleed the system (see chapter 9). Check valve/tubing connections for tightness.
- d) Check the functioning of the rear brakes. If in any doubt, have a Skoda dealer check the valve setting.
Pic. 9.13. Brake pressure control valve spring tension (pickup models)
1. Valve; 2. Adjusting nut; 3. Locknut A 105.00±0.05 mm; 4. Spring; 5. Torsion beam rear suspension.