Solenoid Valve A0009975212 A0009975112 A0009973812 4721729010

A0009975212 / A0009975112 / A0009973812 / 4721729010 solenoid valve for Mercedes-Benz Actros trucks. 3/2-way normally closed solenoid valve for pneumatic control systems. Direct OE replacement part. No mounting hardware or connector seals included. Verify valve function, voltage, and port thread pattern before ordering. Professional installation required.

This solenoid valve group includes four interchangeable part numbers: A0009975212, A0009975112, A0009973812, and 4721729010. These numbers reference the same valve component used across multiple Mercedes-Benz Actros applications. The valve is a 3/2-way normally closed solenoid valve designed for pneumatic control circuits.

The valve is manufactured to Mercedes-Benz OE specifications. The primary OEM supplier is WABCO, a leading manufacturer of commercial vehicle pneumatic systems. The valve operates on 24V DC electrical supply, which is the standard vehicle voltage for Mercedes-Benz Actros heavy-duty trucks.

The valve body is constructed from corrosion-resistant materials suitable for under-chassis and engine bay mounting locations. The design includes an IP6K6K and IP6K9K protection rating. These ratings indicate the valve is sealed against high-pressure water jets and steam cleaning. This protection level is essential for commercial vehicle applications where chassis components are regularly pressure washed.

The valve functions as a normally closed 3/2-way pneumatic solenoid. In the resting state with no electrical current applied, the valve remains closed. Airflow between ports is blocked. When the solenoid coil is energized with 24V DC, the internal plunger lifts and redirects airflow from the supply port to the delivery port. The exhaust port opens simultaneously to release pressure from the downstream circuit.

The operating pressure range extends to a maximum of 188.5 psi. The nominal orifice diameter is 2.2 mm. This size supports adequate flow rates for typical pneumatic actuator and control functions on Actros trucks. Applications include transmission shift actuation, suspension leveling control, brake system modulation, and exhaust aftertreatment pneumatic circuits.

The electrical connection uses a Tyco HDSCS connector with coding index C. The valve draws 600 mA rated current at 24V. The temperature operating range spans from -40°C to +80°C. This wide range accommodates extreme cold starts in northern climates and under-hood heat soak in desert operations.

Cross-reference equivalents include WES472.172.901.0, 4721800020, REMV1012, and V1012. These alternative part numbers may appear on aftermarket packaging or supplier catalogs. All reference the same functional component.

This replacement valve suits vehicles where the original solenoid valve fails to actuate, leaks air from the exhaust port when energized, remains stuck open or closed, or shows visible corrosion damage to the electrical connector pins.

Application notes for A0009975212 valve group. These part numbers are fully interchangeable. A0009975212 represents the current production number. A0009975112 and A0009973812 are earlier superseded numbers. 4721729010 is the WABCO manufacturing number. All four numbers appear on Mercedes-Benz electronic parts catalogs for Actros applications.

Pneumatic system installation. Depressurize the air system completely before removing the old valve. The Actros air system operates at pressures up to 13 bar. Open drain valves on air tanks. Wait for pressure gauge to read zero. Tag electrical connector before removal to identify pin functions if wiring diagram is not available.

Port identification. Port 1 is the supply port from the air tank. Port 2 is the delivery port to the actuator or controlled device. The exhaust port vents to atmosphere when the valve de-energizes. Port threads are V16 x 1.5 JED 388 specification. This is a metric thread profile used on commercial vehicle pneumatic components. Do not force standard metric or NPT fittings into these ports.

Electrical connector. The valve requires a mating Tyco HDSCS connector. Check that the existing vehicle connector matches coding index C. Forcing an incorrect connector damages the valve housing. Apply dielectric grease to connector pins only if the original connector had grease. Some Actros harnesses use dry connectors.

Coil testing. Measure coil resistance across the two electrical pins before installation. Expected resistance is approximately 40 ohms at 20°C. Open circuit indicates failed coil. Short circuit across pins indicates internal damage. Do not install a valve that fails resistance testing.

Leak testing after installation. Apply soap solution to all port connections and the valve body joint seams. Pressurize the system. Small bubbles indicate leakage. Leakage exceeds acceptable limits for commercial vehicle pneumatic systems. Retighten fittings or replace valve if leakage is detected at the body.

Cross-reference verification. The following equivalents are documented: WES472.172.901.0, 4721800020, REMV1012, V1012, MB000.997.51.12, MB000.997.52.12, and MB000.997.38.12. These numbers appear on aftermarket equivalent products. Always verify physical dimensions before using equivalents.

Q1: Which Mercedes-Benz vehicles use these solenoid valve part numbers?
A1: These valves are specifically documented for Mercedes-Benz Actros trucks. They may also appear on Axor and Atego models with similar pneumatic systems.

Q2: What is the difference between A0009975212, A0009975112, and A0009973812?
A2: These are supersession numbers for the same valve component. A0009975212 is the current production number. A0009975112 and A0009973812 are earlier versions. All three are functionally interchangeable.

Q3: Is 4721729010 the same as the Mercedes-Benz numbers?
A3: Yes. 4721729010 is the WABCO manufacturing number for this valve. WABCO is the OE supplier to Mercedes-Benz. The valve with the WABCO number is identical to the Mercedes-Benz branded part.

Q4: What does 3/2-way normally closed mean for this valve?
A4: 3/2 means the valve has three ports and two switching positions. Normally closed means in the de-energized state, the supply port is closed and the delivery port is connected to exhaust.

Q5: Can I test this valve with 12V instead of 24V?
A5: No. This valve requires 24V DC for proper operation. Applying 12V may not generate enough magnetic force to lift the plunger. The valve may not actuate or may chatter.

Q6: What is the maximum pressure this valve can handle?
A6: The maximum operating pressure is 188.5 psi. Do not exceed this pressure. Actros air systems typically operate at 10 to 13 bar. This is within the valve specification.

Q7: What does the IP6K9K protection rating mean?
A7: IP6K9K indicates the valve is dust-tight and protected against high-pressure, high-temperature water jets. This allows the valve to withstand steam cleaning procedures used on commercial vehicles.

Q8: The valve leaks air from the exhaust port when energized. What is the cause?
A8: Air leaking from exhaust when energized indicates internal seal failure. Debris in the valve or worn sealing surfaces prevent the internal plunger from seating correctly. Replace the valve. Internal seals are not serviceable.

Q9: How do I identify which valve function I need for my Actros?
A9: Check the original valve part number printed on the label. Cross-reference with vehicle maintenance records. Different valve functions exist in the Actros pneumatic system. The part number identifies the specific pressure range and flow characteristics.

Q10: What tools are needed to replace this solenoid valve?
A10: Replacement requires a 24mm open-end wrench for the port fittings, small flathead screwdriver for connector lock, and soap solution for leak testing. No special tools are required. Always depressurize the air system before starting.