High-quality Bosch ABS hydraulic block designed for Citroën C4 and Peugeot 307 models. This complete assembly includes the ABS control module, pump and a portion of the wiring harness, making it a practical replacement unit for garages and experienced DIYers. Frequently searched by OEM numbers such as 9659457180, 0265800395, and 0265231486, this unit restores anti-lock braking functionality and fault-free ABS communication when installed and commissioned correctly.

Technical Information

• Manufacturer: Bosch
• Model: Citroën C4, Peugeot 307
• Product Codes: 9659457180, 0265800395, 0265231486
• Additional Numbers: 9649988280, 265800395, 4541J1

Function And Benefits

The ABS hydraulic block houses the electronic control unit, pump motor and hydraulic valves that modulate brake pressure during ABS intervention. It prevents wheel lockup under heavy braking, improves vehicle stability and shortens stopping distance in slippery conditions. Replacing a faulty ABS unit restores proper brake pressure modulation, eliminates persistent ABS fault codes and removes warning lamp indications when the system is correctly bled and reset.

How It Is Replaced

• Disconnect Battery Before Work: Always disconnect the negative battery terminal to avoid electrical damage and unintended pump activation.
• Access And Remove: Locate the ABS hydraulic block in the engine bay (usually adjacent to the brake master cylinder), disconnect the electrical connector(s) and the brake lines, and unbolt the unit from its bracket. Retain sealing washers and replace them if damaged.
• Install New Unit: Fit the replacement unit, tighten hydraulic fittings to manufacturer torque values, reconnect the wiring harness and secure all fasteners.
• Bleed Brake System: Perform a complete brake bleeding procedure to remove air from the system. Use a pressure/vacuum bleeder or follow the vehicle manufacturer’s sequential bleeding method.
• Diagnostics And Reset: After bleeding, clear ABS fault codes and run the ABS pump priming/bleeding routine with a compatible diagnostic tool to fully initialize the unit.

Installation Recommendations

• Always Disconnect The Battery Before Removing The Unit To Prevent Damage.
• Use New Sealing Washers On Brake Lines And Replace Any Damaged Hoses.
• Tighten Brake Line Fittings To Manufacturer Torque Values To Prevent Leaks.
• Perform A Thorough Brake Bleed Immediately After Installation To Avoid Air In The System.
• Use A Diagnostic Tool Compatible With PSA Vehicles (e.g., DiagBox) To Clear Codes And Confirm Proper Operation.

Why This Part Most Commonly Fails

• Corrosion And Moisture Ingress: Salt and moisture accelerate corrosion of hydraulic channels and electrical connectors, leading to valve sticking or electrical faults.
• Pump Motor Wear: The electric pump can wear out after extended use, producing noise or failing to build pressure.
• Contamination: Brake fluid contamination or debris can clog valves and damage internal components.
• Electrical Connector Issues: Corroded or loose connectors cause intermittent faults and communication errors with the ABS ECU.
• Impact Damage: Collisions or strong impacts near the master cylinder area can damage the hydraulic block or mounting points.

Notes For Mechanics And DIYers

This unit is commonly identified and ordered by OE numbers (e.g., 9659457180, 0265800395, 0265231486). Suitable for Citroën C4 and Peugeot 307 platforms. After physical replacement, complete bleeding and a diagnostic check are essential to restore full ABS functionality and remove stored fault codes. If unsure about torque settings, bleeding sequences or diagnostic procedures, consult factory repair literature or a qualified technician.

Used ABS hydraulic unit with wiring harness designed for Citroën and Peugeot models. This component controls hydraulic modulation for ABS and ESP interventions and is often searched for by its product numbers, so listing the reference codes below will help you find the correct replacement quickly. Suitable for professional workshops and experienced DIY mechanics who are comfortable working on the brake system and performing a full bleed and diagnostic check after installation.

Technical Information

• Manufacturer: Stellantis (Citroën / Peugeot)
• Model: Citroën C4; Peugeot 307
• Product Codes: 9657352780, 0265800395, 0265231486, 9649988280, 4541J1
• Other Numbers: 265231486, 265800395

Function

The Hydraulic Control Block (ABS Pump/Valve Block) modulates brake pressure during anti-lock braking and electronic stability (ESP) interventions. It contains hydraulic valves and the pump circuit that rapidly adjusts pressure to individual wheels based on ABS/ESP commands. The unit interfaces with the vehicle wiring harness for sensor and control signals and works together with the ABS control electronics to maintain vehicle stability and shorten stopping distances under emergency braking.

Compatible Models

Intended Applications: Citroën C4, Peugeot 307. Compatibility should be checked against the listed product codes to ensure correct fitment for specific engine and ABS system variants.

Installation Recommendations

• Disconnect The Battery Before Work: Always isolate the vehicle electrical system before removing the unit to avoid electrical damage or accidental airbag/ECU events.
• Vehicle Preparation: Raise and support the vehicle securely; work on a level surface and follow safe lifting procedures.
• Hydraulic Disconnection: Place a suitable container under the vehicle to catch brake fluid. Loosen and remove the brake lines from the unit, cap lines to prevent contamination and air ingress.
• Electrical Connections: Unplug the wiring harness carefully and inspect connectors and pins for corrosion or damage before fitting the replacement.
• Replacement Procedure: Remove the mounting fasteners, swap the unit and wiring section, install new sealing washers where applicable and tighten brake line fittings to the manufacturer’s torque specifications.
• Bleeding And Initialization: After installation perform a complete brake bleed and the ABS/ESP bleed procedure so the pump and valves purge air. Use a diagnostic tool capable of cycling the ABS pump and clearing codes (PSA DiagBox or equivalent recommended) to complete initialization and ensure correct system operation.
• Final Checks: Inspect For Leaks, verify brake pedal firmness, and clear stored fault codes. Test drive at low speed to confirm ABS/ESP operation before returning the vehicle to normal use.

Why This Part Most Commonly Fails

• Brake Fluid Contamination And Moisture: Water-contaminated fluid accelerates internal corrosion and valve sticking.
• Internal Valve Or Pump Wear: Moving parts inside the pump/valve block can wear out over time, reducing performance or causing failure.
• Electrical Connector Corrosion Or Damage: Poor connections or damaged wiring can interrupt control signals and diagnostic communication.
• Mechanical Damage: Impact from road incidents or improper handling during previous repairs can damage the unit.
• Age And Mileage: Like all hydraulic components, seals and internal surfaces degrade with time and use.

Notes And Practical Tips

• Frequently Searched By Part Number: When sourcing this component, use the product codes listed above (e.g., 9657352780, 4541J1) to match the correct unit.
• Wiring Harness: Supplied With A Section Of Wiring — Inspect The Harness Carefully For Broken Wires Or Corrosion Before Installation.
• Service Intervals: There Is No Fixed Replacement Interval; Regular Brake Fluid Changes And Inspections Help Extend Component Life.