198001728 - G001 HANDBRAKE NOT EFFICIENT

When the handbrake is operated the rear wheels are not locked. (A handbrake that is working properly should, when fully engaged, prevent the "take off" of the vehicle from stationary)
Test results
1HANDBRAKE ADJUSTMENT CHECKAll OKProblems encounteredOperation
Check that the handbrake is correctly adjustedMove on to Step 2Adjustment incorrectRestore the correct handbrake adjustment    Op. 3380A04 HANDBRAKE - ADJUST TRAVEL
2CONTROL CABLES CHECKAll OKProblems encounteredOperation
Check:- that the handbrake control cables are correctly fastened;- the condition of the actual cables.Move on to Step 31. Cable fastening slack.2. Cables damaged or broken.3. Rod damaged or broken1. Restore correct fastenings2. Replace the cables involved    Op. 3380A36 LEFT HANDBRAKE CONTROL CABLE - R.R.    Op. 3380A37 RIGHT HANDBRAKE CONTROL CABLE - R.R.3. Replace the rods involved
3BRAKE CALIPER CHECKAll OKProblems encounteredOperation
Check the condition of the rear brake caliper pistonsMove on to Step 4Pistons worn or seizedReplace the rear brake caliper involved    Op. 3310B36 REAR BRAKE CALIPER (ONE), LEFT OR RIGHT - R.R
4CORRECT OPERATION CHECKAll OKProblems encounteredOperation
Check that the fault is no longer presentEnd of diagnosisFault persistsSearch for the problem starting from another symbol