HYDRAULICS 1.79 SINGLE BRAKE VALVE (MICO) (10) - Servicing 9. Remove O-ring (8*) and cup (10*) (note orientation) from spacer (11). Remove O-ring (8*) and O-rings (6*) from sleeve (7). NOTE : Up to Machines S/No.51200471 only. Servicing is normally restricted to the replacement of seals. When the bore of the cylinder or the piston is scored, the brake valve must be replaced. Dismantling 1. Make sure all the blanks are secure in the ports then clean any dirt off the assembly before dismantling. 2. Remove boot (20*) from piston (19). 3. Remove piston (19), springs (15**), (16), (17) and shims (14) from housing bore. NOTE: Some models also use a 6.35 mm (0.25 in.) spacer with shims.
Note the number of shims removed from housing. 4. Examine bearing ( 18) for wear or damage, only remove if necessary. NOTE: Excessive wear on bearing (18) and piston (19) require replacement. 1. Nut 11. Spacer 2. Washer 12. Housing 3*. O-ring 13. Retainer assembly 4. End plug 14. Shim(s) 5. Spring 15.** Spring 6*. O-ring 16. Spring 7. Sleeve 17. Spring 8*. O-ring 18. Bearing 9. Spool 19. Piston 10.* Cup 20*. Boot 5. Remove retainer assembly (13) from housing bore (a ball bearing is pressed into the retainer). 6. Loosen nut (1) and remove end plug (4) from housing. Remove spring (5), nut (1), washer (2) and O-ring (3*) from end plug (4). 7.
Use a wooden dowel to remove spacer (11), sleeve (7) and spool (9) assembly from housing bore. * Included in repair kit ** Not used in all models NOTE: Take care not to scratch or mark sleeve (7) or housing bore.Sleeve (7) and spool (9) are a matched pair and must not be mixed with other parts. Excessive wear on sleeve or spool will require replacement. 8. Separate spacer (11) and spool (9) from sleeve (7). NOTE: Take care not to damage cup or O-ring grooves or bore.