34 21 200 Removing and installing/replacing both rear disc brakes

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IMPORTANT:

Brake pad wear sensor: after removal it must be replaced (brake pad wear sensor loses its retention capability in the brake pad).
Retaining pins and expanding spring: for vehicles older than 48 months it is recommended to replace the retaining spring!

So as not to damage the surface coating, if possible do not mechanically clean the guide surfaces for the brake pads on the brake caliper mounting bracket. Instead, clean with brake cleaner BMW part no. 83 19 2 154 780 and apply a thin coating of brake pad paste BMW part no. 83 19 2 158 851 (3 g) or 83 19 2 158 852 (100 g).

Spread brake pad paste onto the marked surfaces using a brush!

Observe instructions for APPLYING BRAKE PAD PASTE ON BRAKE PADS AND BRAKE ANCHOR PLATE !

Necessary preliminary tasks:

Remove WHEELS .
Remove BRAKE PAD WEAR SENSOR

NOTE: After completing repair work:

Fully depress brake pedal several times so that brake pads contact brake discs.
When installing new brake pads at front and rear axles, brake fluid level must be brought up to "MAX" marking.
Read and comply with notes on BREAKING-IN NEW BRAKE DISCS/BRAKE PADS .
If necessary, when replacing pads, reset CBS display in accordance with factory specification.

Lift out retaining spring (1).

Fig 1: Identifying Retaining Spring

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Remove cover plug (1).

Fig 2: Identifying Cover Plug

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Unscrew guide bolts (1).

Withdraw brake caliper backwards.

IMPORTANT: Tie brake caliper back and do not allow to hang from brake hose.

Installation note:

Tightening torque 34 21 4AZ .

Clean guide screws only; do not grease.

Check threads.

Fig 3: Identifying Guide Bolts

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Replace all guide bolts which are not in perfect condition.

IMPORTANT: When pressing down piston, note brake fluid level in expansion tank.
Overflowing brake fluid will damage the paintwork.

Turn piston back fully with special tool 34 1 050 .

Fig 4: Turning Piston Back Fully Using Special Tool (34 1 050)

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IMPORTANT: Mark any worn brake pads.

In the event of one-sided brake pad wear, do not change brake pads round.

Remove outer brake pad.

Inner brake pad is located with its spring in the piston.

Clean brake pads.

Do not grease backs of brake pads sleeve.

Fig 5: Removing Outer Brake Pad

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Check minimum brake disc thickness:

Position special tool 34 1 280 at three measuring points in area (1) and measure.
Compare measurement result and lowest value with SETPOINT VALUE .

Fig 6: Checking Brake Disc Thickness Using Special Tool (34 1 280)
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IMPORTANT: New brake pads may only be fitted if the brake disc thickness is greater than the MINIMUM BRAKE DISC THICKNESS (MIN TH) .

Check dust boot for damage and replace if necessary.

Clean contact surface (1) of brake piston with brake cleaner and apply a thin coating of brake pad paste.

IMPORTANT: Dust boot must not come into contact with brake pad paste as this may cause the dust boot to swell.

Fig 7: Identifying Brake Piston Contact Surface

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Clean contact surfaces (1) of T-heads/brake caliper housing with brake cleaner and apply a thin coating of brake pad paste.

Fig 8: Identifying Contact Surfaces Of T-Heads/Brake Caliper Housing - Continental Teves 2-Piston Floating Caliper

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Clean contact surface (1) of brake caliper with brake cleaner and apply a thin coating of brake pad paste.

Fig 9: Identifying Contact Surface Of Brake Caliper

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So as not to damage the surface coating, if possible do not mechanically clean the guide surfaces (1) for the brake pads on the brake caliper mounting bracket. Clean guide surfaces (1) with brake cleaner and apply a thin coating of brake pad paste.

Fig 10: Identifying Guide Surfaces For Brake Pads On Brake Caliper Mounting Bracket

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So as not to damage the surface coating, if possible do not mechanically clean the guide surfaces (1 and 2) for the brake pads on the brake caliper mounting bracket. Clean guide surfaces (1 and 2) with brake cleaner and apply a thin coating of brake pad paste.

Fig 11: Identifying Guide Surfaces For Brake Pads On Brake Caliper Mounting Bracket - Continental Teves 2-Piston Floating Caliper

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Lightly coat the T-head of the inner brake pad with brake pad paste in area (1 and 2).

Fig 12: Identifying Areas On T-Head Of Inner Brake - Continental Teves 2-Piston Floating Caliper

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Lightly coat the T-head of the outer brake pad with brake pad paste in area (1 and 2).

Fig 13: Identifying Areas On T-Head Of Outer Brake - Continental Teves 2-Piston Floating Caliper

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