Bosch Rexroth A4VG axial piston hydraulic pump for the Dieci concrete mixer BHD0126 BHD0128 BHD0129 BHD0135 BHD0300
- Product Details
- Product Model
- FAQ
The A4VG is a variable displacement axial piston pump for closed-loop circuits. Displacement is changed by tilting a swashplate. Tilting the swashplate one way sends oil out of port A; tilting it the other way sends oil out of port B. This gives smooth, stepless control of both speed and direction from a single pump.
Key characteristics
Closed circuit: Oil returns directly from the motor to the pump inlet instead of going back to a tank.
Integrated charge (boost) pump: Keeps the low-pressure side supplied, replaces leakage, and feeds the control system.
High-pressure relief valves with pressure cut-off: Protect the circuit from shock loads.
Through-drive option: Lets you flange a second pump (often a gear or piston pump) onto the same shaft, a common way to power auxiliary functions.
Wide size range: Commonly from about 28 cc/rev up to 250 cc/rev, in multiple series.
Pressure rating: Typically up to 400 bar nominal and 450 bar peak on most sizes (verify against the datasheet for your exact size and series).
Common control options
EP: Electro-proportional control, popular on modern machines with electronic controllers.
HD: Hydraulic pilot-pressure control.
DA: Speed-related control, sometimes used on drive circuits.
How the A4VG Works in a Dieci Concrete Mixer
The hydraulic layout on a self-loading mixer typically has two distinct jobs, and it helps to keep them separate.
The travel circuit
The A4VG feeds one or more hydraulic motors that turn the wheels. The operator's pedal or joystick commands swashplate angle. The result is smooth acceleration, dynamic braking through the closed loop, and precise low-speed control when you're inching toward a loading pile.
The drum drive
Depending on the model, the drum may be driven by a separate hydraulic motor supplied from a dedicated pump circuit or from a through-drive-mounted pump. The drum needs consistent torque at a controlled speed, especially under a full, wet load. A stable, properly boosted closed-loop circuit is what allows that.
Common A4VG Problems on Mixer Machines
Construction duty is hard on hydraulics. Heat, dust, and shock loads all show up eventually.
Loss of drive or weak travel
Likely causes include a worn pump, low boost pressure, a stuck or dirty relief or cut-off valve, or a faulty control. Check charge pressure first, since low boost is a common and inexpensive root cause.
Overheating oil
Closed circuits rely on the flushing valve and the cooler to shed heat. A clogged cooler, a failing flushing valve, or an internally worn pump will all push temperatures up.
Noise and vibration
Cavitation from a restricted inlet, aerated oil, or worn bearings is typical. Whining under load often points to starvation on the boost side.
Contamination damage
Dirty oil is the leading cause of premature failure. Fine particles score the piston shoes, slipper pads, and valve plate. Once that happens, the failure spreads through the whole circuit, so a pump replacement without flushing the system will often fail again.
External leakage
Shaft seals, control housings, and port fittings can weep. A leaking shaft seal is often a symptom of excessive case pressure or a blocked case drain.
For more brands and equipment models, please visit https://www.baolilaihydraulic.com/brand/
| Application equipment brands | Application equipment No. |
| Dieci | BHD0126 |
| Dieci | BHD0128 |
| Dieci | BHD0129 |
| Dieci | BHD0135 |
| Dieci | BHD0300 |
Q1: What is the Bosch Rexroth A4VG used for?
A1: It is a variable displacement axial piston pump for closed-circuit hydrostatic transmissions, widely used in mobile machinery such as compact loaders, rollers, and concrete mixers.
Q2: Which A4VG size does my Dieci mixer use?
A2: It depends on the model and year. The reliable answer is on the pump nameplate and in your Dieci parts documentation.
Q3: What is the price and delivery time of the A4VG hydraulic pump for the Dieci concrete mixer?
A3: The specific price and delivery time will depend on the equipment model or specific product model you provide.
Q4: How do I purchase an A4VG hydraulic pump for the Dieci concrete mixer?
A4: Visit https://www.baolilaihydraulic.com/contact/ to contact us and purchase our products through various methods.
