which communicate with the annular chamber 95 as well as in the annular chamber 57 and valve passages 55 all of which communicate with the annular chamber 97 as is well known to those skilled in the art the valve passages 55 and 59 containing high pressure are in commutating fluid communication with the fluid passages 49 in the port plate 19 which are instantaneously in communication with the expanding fluid volume chambers 29e at the same time each of the contracting fluid volume chambers 29c is instantaneously in communication with fluid passages 49 in the port plate 19 which are in commutating fluid communication with valve passages 61 and 65 in the disk valve 47 this exhaust low pressure fluid in the valve passages 61 and 65 is communicated to the outlet port 53 low pressure fluid in the valve passages 61 flows to the central chamber 75 in the balancing ring 67 and from there through the cored passage 100 to the annular chamber 99 which as may best be seen in fig5 is now in open communication with the annular chamber 101 and therefore with the outlet port 53 low pressure fluid in the valve passages 65 is communicated to the axial passages 77 in the balancing ring 67 and from there through the cored passages 102 and 104 to the annular chamber 101 and then to the outlet port 53 therefore with the spool valve 107 in the position shown in fig5 the motor operates in the normal low speed high torque mode in which high pressure is communicated to all of the expanding volume chambers 29e and low pressure is exhausted from all of the contracting volume chambers 29c referring now to fig6 in conjunction with other drawing figures another important aspect.