Does anyone know what would be acceptable case drain on a 763 drive motor. This is related to a thread where we have inspected and resealed the hydrostatic pumps and both drive motors. One of the drive motors failed during use when the clamping bolts came loose (not sure if we used loctite). We have the engine/pump assembly on the shop floor connected to both drive motors. We also have a ball valve inline to the pumps (one valve we just move it line to line to test) and a pressure gauge.
This has been a great test. The pumps both work great getting something greater than 3000 psi. We use the ball valve to lock flow on either side of the motor while applying pressure. I've compared this to stalling the Bobcat when operating 'like when you dig too deep' and the engine dies. In that case I believe the term is that you are dead-heading the pump. This would be applying maximum pressure at the motors and back to the pump.
On one side this happens and we get some flow out of the motor which I'll call case drain. It's minimal and I'll call that acceptable for now. The other motor (where the clamp bolts back out) blows fluid to the ceiling. Obviously, that is not ok. We purchased a new seal kit and have yet to install it.
Here is the Question - Does anyone know what the allowable/acceptable "case drain" is? We could run the engine up to operating speed and close the valve on a pump while operating the drive motor and measure the leakage. This is a personal machine - not using commercially so we don't need perfect. However, it would be good to know that we are in the ballpark of operating. I'll setup a video and post the link by this weekend (Jan 6th). thanks
This has been a great test. The pumps both work great getting something greater than 3000 psi. We use the ball valve to lock flow on either side of the motor while applying pressure. I've compared this to stalling the Bobcat when operating 'like when you dig too deep' and the engine dies. In that case I believe the term is that you are dead-heading the pump. This would be applying maximum pressure at the motors and back to the pump.
On one side this happens and we get some flow out of the motor which I'll call case drain. It's minimal and I'll call that acceptable for now. The other motor (where the clamp bolts back out) blows fluid to the ceiling. Obviously, that is not ok. We purchased a new seal kit and have yet to install it.
Here is the Question - Does anyone know what the allowable/acceptable "case drain" is? We could run the engine up to operating speed and close the valve on a pump while operating the drive motor and measure the leakage. This is a personal machine - not using commercially so we don't need perfect. However, it would be good to know that we are in the ballpark of operating. I'll setup a video and post the link by this weekend (Jan 6th). thanks
