Voith Aquatarder PWR

Brake better with water:

The Voith Aquatarder

Why does a retarder always have to work with oil? Can we not use a medium that is already present for braking: the coolant? Would this not help to significantly reduce maintenance costs?
This, or something like it, is what the questions must have sounded like when development began on the world's first ever water retarder. The result is already on the roads: the Voith Aquatarder.

The Aquatarder operates as the primary retarder: It is mounted on the front of the engine and connected directly to the crank shaft. Like all Voith retarders, it works on the principle of hydrodynamics: The engine crank shaft drives a rotor. The rotor accelerates the operating medium, in this case the cooling water. A stator, which is located opposite the rotor, slows the medium down again. This braking moment is transferred via the rotor and the crank shaft to the vehicle's driveline. The result: The vehicle is decelerated.


Why water?

That's quite simple: Because it's there anyway. When a retarder is used for braking, kinetic energy is converted into thermal energy. The cooling water absorbs the heat directly and transports it to the vehicle cooling system, where it is dissipated. The advantage to you: not only does braking cause no wear, the system also requires no maintenance.


Voith GmbH & Co. KGaA
Commercial Vehicles
Hardtstraße 8
74564 Crailsheim
Deutschland, Germany

Tel.: +49 7951 32-1555
Fax: +49 7951 32-1506

Voith GmbH & Co. KGaA
Gottfried-Linke-Straße 205
38239 Salzgitter
Ms Sabrina Lipok
Tel.: +49 5341 21 5446
Mr Sascha Koch
Tel.: +49 5341 21 4872
Fax: +49 5341 21 1830


Technical Service
Tel. +49 7951/32-1555
Fax +49 7951/32-1506

Ordering spare parts
Tel. +49 7951/32-1644
Fax +49 7951/32-756

Aquatarder PWR for MAN Common Rail
Diesel Engine D20/D26

Technical data

Max. nominal braking torque at cank shaft  1 450 Nm 
Operation Standard choice of operating lever or brake pedal
Operating medium  Engine coolant in compliance with MAN operating instructions 
Control medium  compressed air
Retarder weight net  ca. 33 kg 
Nominal voltage  24 V 
CAN-Bus-specific electronic control system  VERA 

Features and benefits

  • Higher safety
  • Maintenance-free
  • Low service costs
  • Fewer visits to workshops
  • Less fuel consumption
  • Less emissions