Measure no. Subject

US 60830088-07 Rear brake - soft pressure point

Status date (mm/dd/yy) Status Organization

7/31/18 Accepted US, MOT

Date created (mm/dd/yy) Created by PQM Problem reference
7/31/18 Hans-Juergen Jahreiss

Release date (mm/dd/yy) Approved by Dealer release

Allow automatic release

Vehicles affected

E series Engine Body
K42 K46 K46/11 K46/12 K46/13

K47 K47/11 K50 K50/11 K51

K52 K53 K54

Production period (from/to) Feedback (all cases relating to
(mm/dd/yy) Comment on production period measure up to) (mm/dd/yy)
9/1/09 /

Complaint

For exclusive operation of the rear wheel brake with the footbrake lever the driver feels a
soft pressure point or a lengthy brake pedal travel.
The conventional bleeding of the rear brake circuit temporarily alleviates the condition.

With increasing usage, little by little the phenomenon may again occur.

Cause

Due to unknown influencing variables, small amounts of air enter into the control
circuit of the rear wheel brake. With increasing usage this air can, over time and
with exclusive operation of the rear wheel brake using the footbrake lever, be

perceived by the rider as a “soft pressure point” or a “lengthy lever travel”.

Note:

For partial integral brake systems the pressure for the rear wheel brake is generated
by a pump in the ABS modulator through operation of the footbrake lever. If there is
air in the rear control circuit (between the rear tandem brake master cylinder and the

ABS modulator), the pressure build-up is not influenced by the integral function.

If there is air in the rear wheel circuit (between the ABS modulator and the rear brake
caliper), the pump in the ABS modulator can compress small amounts of air in such a
way that there are no tangible functional changes for the rider. The phenomenon is only

detectable during exclusive operation with the footbrake lever.

The very complex influencing factors are currently being determined through extensive

and time-consuming trials in the braking development department.

Note:

With operation of the hand brake lever for the front wheel brake, the vehicle can be
braked within the limits of the legally required deceleration values and safely brought

to a standstill. Because of the dynamic wheel load distribution, the rear wheel brake
plays a lesser role for dynamic braking. In the case of emergency braking (panic braking),

the braking power is almost exclusively transmitted through the front wheel brake.

Measure

Bleed the rear brake circuit manually in accordance with the specifications in the
Maintenance Instructions.

Then call up the following service program and work through it:

Select the fault pattern “Brake system: soft pressure point”, calculate the test plan and
perform the service program "Check the brake pressure point“. You can find a detailed
description of this in the attachment.

Please bleed the affected brake circuit thoroughly over ISTA (incl. modulator). Carry out
the routine at least 2 times. This may have to be repeated depending on the amount of
air ingress.

After the break bleed process, apply pressure overnight to the rear brake circuit.

To do this, a weight 10-15 kg (22-33 Ibs) can be attached to the footbrake lever.

Then flush the system again (at least twice the contents of the reservoir).

The repair tasks can also be invoiced under warranty after expiration of the warranty

period using the defect code 34 00 90 72 00 "Rear brake system not adequately bled".

Complaint
Fault location Fault type Fault place

Brakes Too soft Rear

Cause

# Fault location Fault type Fault place
. 1 34/51 ABS 2 modulator Pressure not OK
Repair Task Special Clearance Area
Checking, repairing, No Chassis and Suspension
replacing
# Fault location Fault type Fault place
, 2 34/21 Rear brake Pressure drop / loss
Repair Task Special Clearance Area
Checking, repairing, No Chassis and Suspension
replacing
# Fault location Fault type Fault place
. 3 34/31 Brake master Malfunction
cylinder
Repair Task Special Clearance Area
Checking, repairing, No Chassis and Suspension
replacing
Fault code
Progman / DIS / ISTA /ISTA/P.
System State Version

© 2002-2018 BMW OF NORTH AMERICA, LLC. ALL RIGHTS RESERVED.

Check the brake pressure point

1. Identify motorcycle, start vehicle test

SS 4) | DI

VIN: 7183019

FACAN —

Fault memory Not existent [©] Ecu responding [@]Ecunotresponding [6] Ecu siate unknown

2. Select fault pattern

2.1. Select Main group [002 Chassis and suspension]

x

KL15: 13.9V KL30: 13.9V

Text Search Input fault code
eS eres
z Layer 1:
001 Drive Perceived symptoms (old)
002 Chassis and suspension
003 Electrical system

Number of fault memories: 0/0 No. fault pattems: 0

Undo all Undo ‘Add fault pattem

2. Select fault pattern

2.2. Select Main group [Antilock braking system ABS]

Intgrated Service Tecnica al x

VIN: 2183019 i AOA KL15: 39V KL30: 13.9V

Electronic suspensidh adjustment

RDC tyre pressure control

Number of fault memories: 0/0 No. fault patterns: 0

Undo all, Undo ‘Add fault patiem = Shiow ull pation late test pian

2. Select fault pattern

2.3. Select the fault pattern [Brake system: soft pressure point], then push button “Add fault pattern”

il 4 0)

Vehicle: RIK50/R 1200 GS/USA0A11/2012/05

Insufficient venting of pressure modulator

No ABS release after driving off

Number of fault memories: 0/0 — No. fault pattems: 0

Undo all Undo ‘Add fault pattem |) Show fu pattem

Calculate test pkan

3. Calculate test plan

2] &

KL15: 139V KL30: 139V

Deed

Perceived symptoms (old)

Number of fault memories: 0/0 | No. fault pattems: 1

Undo a undo fe ult paliem Show fault pater Caleutat tt plan

|

Note: fault pattern selected

4. Operate serviceprogram

etcaon fal 1 8 D|

Vehicle: RUKSO/R 1200 GS/USA/0A11/2012/05 KL15: 13.9V KL30: 139V

Cenc

ro essure point

Hits: 111 Filler Default [Not called [8] Periormed [6] Minimized [®] Canceled _[@] Suspected

Back Filters ‘Sbowsymptoms Collapse /expand _Set standard filter Display

lp

4. Operate serviceprogram
4.1. choose brake circuit

VIN: 2183019 Vehicle: R/KBOIR 1200 GS/USA/0A11/2012/05 KL15: 139V KL30: 13.9V

BMW Motorrad Integral ABS IV

‘The BMW Motorrad Integral ABS IV is based on the tried-and-tested MK100 from
Continental-Teves and Is adapted to the special requirements and functions in
Motorrad.

Front brake circuit ‘The ABS control operation is effected separately for the front and rear wheel (2-channal
ABS).

Rear brake circuit

Brief component description

‘The ABS control unit (HECU) is made up of the hydraulic unit (HCU), the contol unit
(ECU) and the electrical pump motor.

4. Operate serviceprogram
4.2. Notice instructions

ean oan El x