Hydraulic brakes

Very low cost dynos can be built using a hydraulic brake, as long as the HP is reasonably low, say below 100 to max 150 HP. All you need is a hydraulic pump and an adjustable valve plus associated plumbing/tank. Below you see an example of a hydraulic brake running an earlier version of YourDyno.

hydraulic dyno
A simple and effective hydraulic brake dyno used up to about 85hp

See it in action here.

Here is what you need:

    1. High Pressure Hydraulic Gear or Vane Pump. Click here to learn how to choose the right hydraulic pump.
    2. A Flow control valve (example 1example 2example 3). Your valve should be made for fine adjustments.
    3. A high pressure hydraulic hose between your pump and your valve (example).
    4. A car wheel hub bearing (example) or something else that fits your setup to ensure the pump can rotate.
    5. A mechanical rig and a hydraulic tank with fittings and plumbings
    6. The YourDyno instrumentation kit

Note that the dyno in the video only has a (car hub) bearing on one side of the retarder. The axel bearing of the kart being tested serves as the second bearing. More details on this hydraulic brake here!

In the video above you see the the pump is kept from rotating by an arm towards the front of the car. It is connected to the load cell (part of YourDyno kit). You see the RPM sensor (also included) over the pump flange.

The total cost of the mechanical parts for this dyno was only around $200. It worked very well and was used up to about 85HP.


Last updated byJostein on March 23, 2019


  1. Glen D Bien
    April 23, 2019 @ 2:15 am

    What brand and size of hydraulic pump was used on this project?

    What sensors feed into the YourDyno kit?
    RPM – What type of sensor and system was used to pick up the RPM and where was it located?
    Load Sensor/cell – What type?
    How do you size this? For an expected torque, e.g. 120 HP & 100 Torque = 100 ft pounds torque?

    Is there a write up or video explaining how you dyno using this type of setup? It appears this setup starts with the oil flow valve open and you start the hit, you press the accelerator until you hit your desired rpm but it isn’t clear how much or when you tighten down on the oil flow. Is there an explanation on this system or the water systems somewhere on your forum?

    How do you determine how far on the arm you set up the load cell?

    What is the best type of hub mount system for a two stroke snowmobile motor based race car with a CVT type transmission in the 100-125hp range?


    • admin
      June 10, 2019 @ 9:36 pm

      Hi, it is just a simple gear pump. You need to choose one with appropriate flow, see links above. You can use load cell and RPM sensor from YourDyno. Pretty simple setup, the flow is more and more restricted as you close the valve, and the RPM will drop accordingly.


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