A test system for testing torque converters, other fluid coupling devices, and the like, e.g., devices that couple engine power to driveline power. The test system drives the test device with a first hydraulic motor, which is itself driven by a first hydraulic pump. At the output of the test device, a second hydraulic pump absorbs the power from the test device, and drives a second hydraulic motor, which in turn drives the first hydraulic pump. A make-up motor is used to also drive the first hydraulic pump, to make up for any additional power desired for testing.
Denis Long; Glenn Wendel