UPPERSTRUCTURE / Control Valve 12. Clamp spool (54) in a vise by using wooden pieces. Install O-ring (56) and backup ring (55) to spool (57). Install spool (57) to spool (54). Install spool (54) and spring (58) to housing (1). 13. Install the spools (51, 50, 47, 37) assembly, O-rings (59) (4 used) and (4) to housing (1). Install cap (62) to housing (1) with socket bolts (63) (6 used). : 42 N m (4.3 kgf m. 31 lbf ft) 14. Install O-ring (60) to plug (61). Install plug (61) to cap (62). : 8 mm : 54 N m (5.5 kgf m, 40 lbf ft) 15. Install O-ring (65) to plug (66). Install plug (66) to cap (64). : 21 mm : 19 N m (2.0 kgf m, 14 lbf ft) W2-5-25