Parking Brake System: Adjustments
34 10 014 Adjusting handbrakeSpecial tools required:
^ 32 1 030
Perform inspection in the following manner:
When 1st ratchet is engaged, no braking force should be exerted.
The difference in wheel circumferential forces between the left and right wheels may deviate by max. 30 % from the greater value (measured on brake analyzer).
The handbrake must be readjusted in the event of greater deviations in the wheel circumferential force!
It must be possible to brake with locked wheels with the handbrake.
The handbrake must be readjusted whenever the actuation stroke is greater than 10 teeth.
Note:
The handbrake can only be adjusted correctly when the parking brake Bowden cables and all moving handbrake parts are free to move and fully operational.
Basic handbrake adjustment is necessary:
^ When replacing parking brake shoes.
^ When replacing brake disks.
^ In event of excessive actuation stroke (10 teeth).
^ When replacing parking brake Bowden cables
1. Setting instruction for brake shoes (basic setting)
Unclip handbrake lever trim (1) at rear and tilt forwards.
Lock adjuster unit (ASZE).
Using special tool 3210307 press stop (2) of adjusting spring back to such an extent that retaining hook (3) engages in stop (2).
Completely unscrew one wheel stud on each rear wheel.
Installation: Tightening torque 3610 lAZ.
Turn wheel until adjustment screw is visible in tapped hole.
Turn adjusting screw with a screwdriver until the wheel is no longer able to turn.
Then unfasten the adjusting screw 8 notches.
Unlock adjuster unit (ASZE).
Lever restraint hook (2) outwards with a suitable screwdriver (1).
Restraint hook (2) must disengage from stop of adjusting spring.
2. Setting instruction for parking brake Bowden cables
The handbrake lever must be applied 5 times to approximately 400N actuating force.
2.1. On brake analyzer
0th tooth (handbrake released
Vehicles with manual transmission: Shift lever in neutral position.
Vehicles with automatic transmission: Selector lever in N"" position.
^ Without locking differential <150 N.
^ With locking differential < 200 N (possibly odd display).
1st tooth:
No increase in braking force with regard to 0th tooth. Indicator lamp can be lit.
2nd tooth: An increase in braking force must take place, indicator lamp must be lit.
3rd tooth: Increase in braking force.
4th tooth: The brake force display must have reached > tooth: 500 N.
3. Braking in the duo-servo parking brake
The following braking-in procedures are applicable in case of insufficient braking effect or after replacing brake disks and/or brake shoes.
3.1. On brake analyzer
Apply handbrake lever until wheel circumferential force on first wheel is 800 N.
Lock lever in next lower tooth.
Release handbrake lever after approximately 2 minutes.
3.2. When driving on road
(If possible inside the company grounds or on an unused road)
At approximately 40 km/h, apply handbrake lever until braking action can be felt.
Pull up handbrake lever into next notch and drive on for approximately 400 m.
A basic requirement is that handbrake is adjusted uniformly.
Note: Repeat braking-in procedure if necessary; allow brake to cool down sufficiently.