Firstly, locate the power steering reservoir on your Massey Ferguson 135. This will likely have an automatic flush valve. If the valve is open, the fluid can be drained completely out of the reservoir. If not, the valve should be opened and fluid will be drawn out. After this step, refill the reservoir with new fluid. To ensure that no old fluid remains, the system can be bled as detailed in your Massey Ferguson 135 owner’s manual. This process will ensure that all of the old fluid is replaced by new and your power steering system is ready to go.