Rexroth A11VO axial piston hydraulic pump for the Sermac Concrete mixer truck 2401187 2401216 2401246 2401251 2401271 2401295 2401310

The A11VO is an open-circuit, variable-displacement axial piston pump from Bosch Rexroth, built on the swashplate principle. A rotating cylinder block carries pistons that stroke against an inclined swashplate. Changing the swashplate angle changes the flow per revolution, from near zero to maximum, without changing engine speed.

That matters on a truck because the engine is also driving the road, the PTO, and other loads. A variable pump gives you flow only when you need it.

Why the A11VO Suits Concrete Mixer Trucks

Mixer trucks put a hydraulic system through an unusually rough duty cycle. The pump has to cope with:

Heavy start-up torque when a full drum of dense, wet concrete begins to turn

Constantly changing load as the mix stiffens or the truck tilts on a slope

Dust, vibration, and heat from the construction environment

Variable engine speed tied to the vehicle PTO

Benefits of a variable-displacement pump in this duty

1. Lower wasted energy. A fixed-displacement pump keeps pushing full flow and dumps the surplus over the relief valve as heat. A variable pump like the A11VO delivers what the circuit demands.

2. Cooler oil. Less throttling means less heat, which extends seal, hose, and oil life.

3. Smoother drum control. Load-sensing or proportional control lets the operator adjust drum speed with less jerk.

4. Fuel savings. Less parasitic load on the PTO means the engine works less.

How to Choose the Right A11VO for Your Sermac Truck

Match displacement and flow

Displacement (cm³/rev) multiplied by PTO shaft speed gives theoretical flow. Size for the flow your motor and functions need at working PTO rpm, not just at peak engine speed. An oversized pump wastes money and installation space. An undersized one runs hot and struggles in cold starts.

Confirm pressure and control type

Pressure control (DR): holds a set pressure and reduces displacement when it's reached

Load-sensing (LR/LRDS): delivers only the flow and pressure the load demands, which is efficient for multi-function machines

Electro-proportional (EP): allows electronic control from the truck's controller

Using the wrong control on a machine designed for another is a common cause of "new pump, same problem" complaints.

Check the mechanical interface

Mounting flange and pilot diameter

Shaft type and spline count

Rotation direction (clockwise or counter-clockwise, as seen from the shaft end)

Port sizes and positions

Through-drive requirement, if a second pump is stacked on the back

Installation Best Practices

A perfectly good pump can be destroyed in the first hour by a poor installation.

1. Flush the system and replace the filters before fitting a new pump, especially after a failure. Debris from a failed pump will contaminate the replacement.

2. Fill the pump case with clean oil through the case drain port before starting. Never run an axial piston pump dry.

3. Check alignment and PTO coupling. Misalignment and shaft loading wear bearings and shaft seals fast.

4. Keep the suction line short, large, and airtight. Air ingress causes cavitation, noise, and early wear.

5. Route the case drain to the reservoir below the oil level, at low back-pressure, as the manufacturer specifies.

6. Start at low speed, bleed air, and confirm there are no leaks before bringing the system to full load.

For more brands and equipment models, please visit https://www.baolilaihydraulic.com/brand/

Q1: How long does an A11VO pump last?

A1: Service life varies widely with contamination, oil temperature, duty cycle, and installation quality. Well-maintained pumps in clean systems can run for many thousands of hours, while contaminated ones can fail far sooner.

Q2: What should I do before starting a new pump?

A2: Prime the case with clean hydraulic oil, check suction lines for tightness, confirm rotation direction, and run at low speed while bleeding the system.

Q3: What is the price and delivery time of the A11VO hydraulic pump for the Sermac Concrete mixer truck?

A3: The specific price and delivery time will depend on the equipment model or specific product model you provide.

Q4: How to purchase an A11VO hydraulic pump for a Sermac Concrete mixer truck?

A4: You can visit https://www.baolilaihydraulic.com/contact/ to contact us and purchase our products through various methods.