Used hydraulic distributor

How a hydraulic distributor works

The distributor is the hub of the hydraulic circuit. It receives high-pressure oil from the hydraulic pump outlet and directs it to the selected actuator: arm and bucket cylinders, travel motors or rotation hydraulic motors. Inside the distributor body, one or more spools slide in their bore and open calibrated passages. They control the flow direction and, on proportional models, the flow rate. Cylinder drift, abnormal slowness, or lack of pressure response often indicate wear of the spools or internal seals.

Double-acting, single-acting, and open-centre hydraulic distributors

• Double-acting: oil supplies both cylinder chambers for active movement in both directions. This is standard on mini excavators, excavators, loaders, and telehandlers.
• Single-acting: only one chamber is supplied, the return being by gravity or spring. Found on blades, auxiliary arms, and some attachments.
• Open-centre: in neutral position, oil flows freely to the tank without unwanted pressure build-up.
• Closed-centre: ports are blocked in neutral to hold the load or supply another circuit.

Ports, sections, and hydraulic distributor schematic

The number of ports and positions is read from the hydraulic distributor schematic, using ISO 1219 standard symbols. A 4/2 (four ports, two positions) controls a single double-acting function; a 4/3 adds a neutral position. Earthmoving machines mainly use multi-section blocks: monoblock distributors cast as one piece or stackable distributors composed of assembled elements. On the body, identify ports P (pump), T (tank return), A and B (actuators), then note the max flow in L/min and max pressure in bar indicated on the plate: these values take precedence over assembly compatibility alone.

Manual, 12V or 24V electric, proportional control

• Manual control: lever or cable acts directly on the spool, a robust solution for compact machines and attachments.
• 12V electric hydraulic distributor: solenoid electric control, common on mini excavators, dumpers, and forklifts.
• 24V electric hydraulic distributor: standard on excavators over 20 tons and wheeled loaders. A 24V solenoid does not work on a 12V system.
• Proportional hydraulic distributor: spool opening modulated according to joystick signal, used in cranes and electrohydraulic controls.
• Piloted hydraulic or pneumatic control: controlled by low-pressure hydraulic circuit or air. Pneumatic control is mainly found on truck cranes.

Hydraulic distributor spool: the key wear part

The spool slides thousands of times under high pressure in its bore. Over many cycles, clearance increases causing internal leaks: the cylinder drifts under load, power drops, and control becomes imprecise. On some models, the spool alone can be replaced. On others, a complete used distributor is preferable to restore original clearances and reliable long-term operation. Our technicians will guide you to the suitable solution based on the distributor reference.

Hydraulic distributors for mini excavators, loaders, and cranes: block or kit

• Mini excavator: the main block controls translation, rotation, arm, and bucket. Our used distributors for JCB , Caterpillar , Liebherr , and Volvo cover many models.
• Wheeled loaders and backhoe loaders: arm cylinders, bucket cylinders, and front attachments, notably for Case and Volvo.
• Hydraulic excavators: Caterpillar, Komatsu, Hitachi, Liebherr, and Mecalac in our dismantlings.
• Crane hydraulic distributor kit: verify the flow allowed by the safety valve and the solenoid voltage.
• Material handlers/telehandlers: boom and attachment distributors according to availability.

Used double-acting and single-acting hydraulic cylinders

The distributor and cylinder work together, with manual or electrohydraulic control: a double-acting distributor drives a double-acting hydraulic cylinder, a single-acting one a single-acting cylinder. When a cylinder leaks or deforms, check the distributor supplying it, and vice versa. Codimatra offers used arm, bucket, boom, steering, and skip cylinders, dismantled and tested in workshop like our distributors. See our range of used hydraulic cylinders to complete your refurbishment.

Used 12V solenoids, pumps, and hydraulic equipment

• 12V and 24V hydraulic solenoids: electric control of distributors and auxiliary circuits.
• Used hydraulic pumps: main, steering or travel pumps supplying the distributor.
• Swivel joints and oil coolers for excavators.
• All used hydraulic equipment is grouped in our hydraulics range.

Used hydraulic distributors at Codimatra

Codimatra, part of the Dubreuil group based in Castelculier near Agen, has over 45 years of expertise in used spare parts for public works equipment, with more than 18,000 references in stock. Each hydraulic distributor is dismantled from a selected machine, cleaned and tested in our workshop before sale. Parts are sold as-is, at the listed price or by quote, and shipped throughout France and internationally. Provide the brand, model, and original reference: our technicians validate flow and pressure compatibility before shipping.