TOST Stahlbus Bleeder Valve
The filling and bleeding of hydraulic brake systems is one typical task in the maintenance field. We recommend the TOST Stahlbus Bleeder Valve to simplify this task considerably. In every TOST brake assembly the Stahlbus Bleeder Valve is mounted as a standard, in all other brake assemblies it can be retrofitted easily. One person can perform the filling "from bottom to top" thanks to an integrated non-return valve. When filling the system "from bottom to top", the additional integrated gasket eases the procedure clearly.
The TOST Stahlbus Bleeder Valve consists of an upper part with the active components and lower part. The lower part is the adapter for installation in the brake caliper. The correct function is ensured by the interaction of the upper and lower part.
The most popular TOST Stahlbus Bleeder Valve are highlighted in the table. Other P/N's may take up to 4 weeks for delivery.
History of TOST
TOST has more than 60 years of experience in the development and manufacturing of aviation safety equipment. It's a family business – run in the fourth generation – they stick to the motto: Conserving the well-proven system – Developing forward.
The cornerstones of their corporate policy are:
Customer satisfaction is their highest goal. The customer is the king – he should like to come back – and not like to send the product back.
Since 1969 TOST holds a LBA approval as Design and Production Organization. (LBA= German Aviation Authorities). In the meantime, all approvals are issued by the EASA. In yearly audits through the aviation authorities, the compliance with quality standards is checked and kept record of. Over and above those official regulations, they live the quality thought in their every-day work.
Modern manufacturing techniques, economical resource management and the long lifetime of TOST products are their contribution to the protection of the environment. Gliding is an ecologically friendly sport.
Long standing relations to their customers, suppliers and employees stand for the continuity in their company.
Three Modes of Operation
Normal Operation. The TOST Stahlbus Bleeder Valve is completely closed and seals the brake system reliably. Only in this operation mode the brakes may be used.
Filling. The Stahlbus bleeder valve is open as wide as necessary that the hydraulic fluid can flow through. In this mode you can use vacuum filling or bleeding accessories. Thanks to the integrated gasket in the Stahlbus bleeder valve the brake system is sealed against the intrusion of air through the thread.
Bleeding. The Stahlbus bleeder valve is open as wide as necessary so that the integrated non-return valve can take effect. Any other usual bleeder valve must be closed after each operation, e.g. the actuation of the brake flat lever, to prevent the intrusion of air or old brake fluid. However, the Stahlbus bleeder valve will do this automatically. The seal prevents intrusion of air an leaking brake fluid during operation.
Exchange of the existing bleeder valve through the Stahlbus bleeder valve on the brake caliper.
• Check the thread of the bleeder drill in the brake caliper and the snug fit for contamination and damages; clean if necessary.
• Empty the brake system acc. to manufacturers specifications (we suggest to use the Stahlbus vacuum filling and bleeding pump); take care of environmentally friendly disposal of the hydraulic fluid.
• Demount the existing bleeder valve; use only the corresponding thread (picture below)
• Screw the lower part of the Stahlbus bleeder valve into the bleeder drill in the brake caliper with a ring spanner size 7/16″.
After each filling of the brake system or after an exchange of the hydraulic fluid (acc. to manufacturer), the brake system has to be bleeded. Air in the system can lead to weakened brake force or a complete brake failure.
• Loosen the upper part of the Stahlbus Bleeder Valve by half a turn; hold the lower part of the Stahlbus bleeder valve tight with a ring spanner so that it does not loosen from the brake caliper (picture 6 = 0.5 turns). In this position, the ball in the non-return valve will close th opening with the effect of the spring in such a way that the brake system is without pressure. No hydraulic fluid can extrude from th Stahlbus Bleeder Vale and no air can intrude into the system. If the upper part is opened too far, the non-return valve function does not work. If it is not opened wide enough, the ball hits its seat (you hear a clack) and no hydraulic fluid can get through.
• Plug a recipient for used hydraulic fluid and a hose into the hose adapter of the Stahlbus Bleeder Valve (picture to the left).
• Actuate the master cylinder (e.g. pulling the brake flaps lever) and press the hydraulic fluid through the Stahlbus Bleeder Valve into the recipient.
• Return the brake flaps lever in the basic position. The ball in the non–return valve closes the opening immediately and no air or used hydraulic fluid can intrude in the brake system.
• Repeat action until you get best results (hydraulic fluid comes out without air bubbles) (picture 8); pressure point of the brake is optimal.
• Tighten the upper part of the Stahlbus Bleeder Vale with the correct fastening torque (picture 9 = Steel 6 Nm); check afterwards for correct seat in the brake caliper.
• Repeat work on all bleeder valves of the brake system. Put on protective caps.