DISASSEMBLY AND REASSEMBLY


caution Use the special tool power piston replacer (MB992328) to hold the HBB, otherwise its component will be deformed or damaged due to its own weight.




Disassembly steps
<<A>>
·
 Holding the HBB


1.
 Clevis


2.
 Nut


3.
 Boot
<<B>>
 >>B<<
 4.
 Snap ring
<<C>>
 >>B<<
 5.
 Power piston assembly (including brake booster inner plug)
<<C>>
 >>B<<
 6.
 Brake booster inner plug
<<C>>
 >>B<<
 7.
 Power piston assembly
<<D>>
 >>B<<
 8.
 Master cylinder piston assembly


9.
 Filler cap


10.
 Reservoir assembly


11.
 Grommet
<<E>>
 >>A<<
 12.
 Accumulator


13.
 O-ring


14.
 Spring


15.
 Silencer tube


16.
 Hose


17.
 Hose clip


18.
 Tube


19.
 Brake booster inner clamp


20.
 Lead wire


21.
 Bracket


22.
 Pump motor assembly


23.
 Master cylinder and hydraulic unit assembly

DISASSEMBLY SERVICE POINTS

<<A>> HBB FIXING
1.Fix the special tool power piston replacer (MB992328) to the vice.



2.
caution When handling the HBB, hold the stud bolt or the aluminium body at the front or rear end.
Fix the HBB to the special tool power piston replacer (MB992328) by using the HBB mounting nut as shown in the figure.

<<B>> SNAP RING REMOVAL

1.
caution Do not turn the bolt of the special tool power piston replacer (MB992328) with a tool. Turn the bolt by hand.
Place the piston of the special tool power piston replacer (MB992328) against the end of the brake booster inner plug as shown in the figure. Turn the bolt by hand, and press the brake booster inner plug into the aluminium body.

2.Insert a precision screwdriver (A) through the hole on the lower side of the aluminium body. While pressing the snap ring, remove the snap ring using another precision driver (B).
3.Remove the piston of the special tool power piston replacer (MB992328).

<<C>> BRAKE BOOSTER INNER PLUG/POWER PISTON ASSEMBLY REMOVAL
1.Install the clevis locking nut to the thread of the power piston assembly.

2.Connect the bolt of the special tool power piston replacer (MB992328) and the power piston assembly as shown in the figure, and fix them with the clevis locking nut.

3.
caution Do not turn the bolt of the special tool power piston replacer (MB992328) with a tool. Turn the bolt by hand.
Turn the bolt anti-clockwise, and pull out the power piston assembly and the brake booster inner plug from the aluminium body.

<<D>> MASTER CYLINDER PISTON ASSEMBLY REMOVAL
caution Do not use a tool, since the inner side of the cylinder may be damaged.
Pull out the master cylinder piston assembly from the aluminium body with fingers.

<<E>> ACCUMULATOR REMOVAL
caution When removing the accumulator, use a rag to prevent the brake fluid from dripping on the pump motor.

Remove the accumulator with the special tool accumulator wrench (MB991926) as shown in the figure.
note For how to discard the accumulator, refer to .

REASSEMBLY SERVICE POINTS

>>A<< ACCUMULATOR INSTALLATION

caution Before installing the accumulator, make sure that the spring has not fallen off. If the accumulator is installed without the spring, it may be damaged.

Using the special tool accumulator wrench (MB991926), install the accumulator as shown in the figure.

>>B<< MASTER CYLINDER PISTON ASSEMBLY/POWER PISTON ASSEMBLY/BRAKE BOOSTER INNER PLUG/SNAP RING INSTALLATION

1.Insert the master cylinder piston assembly into the aluminium body.

2.
caution An adequate amount of special grease is applied to the inner diameter of the accessory brake booster inner plug. Do not touch the inner diameter of the brake booster inner plug, because the HBB failure will result.
Install the brake booster inner plug to the power piston assembly. Insert the power piston assembly (including brake booster inner plug) into the aluminium body to the position shown in the figure.

3.
caution Do not turn the bolt of the special tool power piston replacer (MB992328) with a tool. Turn the bolt by hand.
Place the piston of the power piston replacer (special tool: MB992328) against the end of the brake booster inner plug. Turn the bolt by hand, and insert the power piston assembly (including brake booster inner plug) into the aluminium body.
note Install the snap ring to the piston of the special tool power piston replacer (MB992328) before insertion.
4.Install the snap ring to the aluminium body as described in Step 3.
5.Remove the piston of the special tool power piston replacer (MB992328).