10 A Foreword – Reading instructions 1. Hydraulic force (solid double line) 2. Flag pressure check connection (Check point), indicates that there is pressure check connection for checking pressure signal 3. Flag diagnostic test, indicates that signal can be checked with diagnostic test, see section 8 Control system, group 8.4 Diag- nostics 4. Illustration of function, (applied brake) 5. Component list 6. Position number in illustration, reference to component list 7. Electric power (solid single line) UDRF01.04GB Maintenance manual DRF 400–450