2 so as to come into contact with the face 34 a of the base 34 the portions of the extended plate 57 2 corresponding to the screw holes 60 1 extend to the outside one end of a cylindrical projection 58 2 is integrally formed in the extended plate 57 1 the fastening bolt 61 to be screwed into the screw hole 60 1 is inserted into the cylindrical projection 58 2 the lock head 61 a of the fastening bolt 61 engages with the other side of the cylindrical projection 58 2 the cover 47 includes an arm 59 2 which covers the extended plate 57 2 and the cylindrical projection 58 2 in order to make it possible to insert the fastening bolts 61 into the cylindrical projection 58 2 from above as well as to engage the lock head 61 a of the fastening bolt 61 with the other side of the cylindrical projection 58 2 even in the third embodiment the same effects as those obtained in the first embodiment can be obtained fig1 and 13 show a brake hydraulic controller according to a fourth embodiment of the present invention the same reference numerals are used to designate the corresponding elements in each of the previous embodiments in fig1 a seal groove 483 having a substantially u shaped cross section is formed along the entire circumference of the.