The power steering system on a Massey Ferguson 35 should be periodically flushed due to the tractors age. It has been suggested to flush the power steering system ever 15 to 20 hours of usage. To flush the system, first start by warming up the tractor engine to operating temperature. Then shut off the engine and lift the hood. Remove the power steering pump reservoir. Clean the reservoir and replace the fluid with ATF fluid. It is best to use ATF fluid that is compatible with Dexron II and Type F. Reconnect the reservoir to the pump and start the tractor. Allow the tractor to run for a few minutes and check for any leaks or signs of contamination. After the system appears to be functioning properly, turn off the engine and replace the reservoir with the power steering fluid. Wait a couple of minutes and check for any leaks or signs of contamination again prior to closing the hood.