Integrated Control Unit - MK25: Removal

Disconnect negative (-) battery cable from battery post and isolate.

CAUTION: Vacuum in power brake booster must be pumped down (removed) before removing master cylinder from power brake booster. This is necessary to prevent power brake booster from sucking in any contamination as master cylinder is removed. This can be done simply by pumping brake pedal, with vehicle's engine not running, until a firm feeling brake pedal is achieved.

With engine not running, pump brake pedal until a firm pedal is achieved (4-5 strokes).
Remove nuts fastening coolant recovery bottle in place and reposition bottle with hoses attached out of way. (Refer to COOLING/ENGINE/COOLANT RECOVERY PRESS CONTAINER - REMOVAL)

CAUTION: Before removing master cylinder from power brake vacuum booster, master cylinder and vacuum booster must be thoroughly cleaned. This must be done to prevent dirt particles from falling into power brake vacuum booster.

Thoroughly clean all surfaces of brake fluid reservoir and master cylinder, paying special attention to area where master cylinder attaches to power brake booster. Use only Mopar(R) Brake Parts Cleaner or equivalent.

Disconnect wiring harness connector from brake fluid level switch in master cylinder brake fluid reservoir. See Fig 1.

Fig 1: Brake Fluid Level Switch Connector

Courtesy of DAIMLERCHRYSLER CORP.

1 - MASTER CYLINDER RESERVOIR

2 - WIRING CONNECTOR

3 - ABS ICU

4 - BRAKE FLUID LEVEL SWITCH

Disconnect primary and secondary brake tubes coming from master cylinder at ABS ICU. See Fig 2. Cap off brake tubes and install sealing plugs in open brake tube outlet ports of ICU.

Fig 2: Primary And Secondary Brake Tubes At ICU

Courtesy of DAIMLERCHRYSLER CORP.

1 - MASTER CYLINDER

2 - PRIMARY BRAKE TUBE NUT

3 - ABS ICU

4 - SECONDARY BRAKE TUBE NUT

Remove two nuts attaching master cylinder to power brake booster. See Fig 3.

Fig 3: Master Cylinder Mounting

Courtesy of DAIMLERCHRYSLER CORP.

1 - ENGINE INTAKE MANIFOLD

2 - BOOSTER VACUUM HOSE

3 - POWER BRAKE BOOSTER

4 - MASTER CYLINDER

5 - PRIMARY BRAKE TUBE

6 - SECONDARY BRAKE TUBE

7 - ABS ICU

8 - MASTER CYLINDER MOUNTING NUT (2)

Slide master cylinder straight out of power brake booster.

CAUTION: Seal on rear of master cylinder is used to create seal for holding vacuum in power brake vacuum booster. Vacuum seal on master cylinder MUST be replaced whenever master cylinder is removed from power brake vacuum booster.

Remove vacuum seal located on mounting flange of master cylinder. Vacuum seal is removed from master cylinder by carefully pulling it off rear of master cylinder. Do not attempt to pry seal off master cylinder by inserting a sharp tool between seal and master cylinder casting.

Disconnect four Chassis brake tubes at ABS ICU. See Fig 4. Cap off brake tubes and install sealing plugs in open brake tube outlet ports of ICU.

Fig 4: Chassis Brake Tubes At ICU

Courtesy of DAIMLERCHRYSLER CORP.

1 - L.F. BRAKE TUBE NUT

2 - R.F. BRAKE TUBE NUT

3 - L.R. BRAKE TUBE NUT

4 - R.R. BRAKE TUBE NUT

5 - ICU

Disconnect 47-way wiring connector at CAB. See Fig 5.

Loosen 2 bolts fastening ABS ICU bracket to frame rail. See Fig 5.

Fig 5: CAB Wiring Connector

Courtesy of DAIMLERCHRYSLER CORP.

1 - ICU MOUNTING BOLTS ON FRAME RAIL

2 - HARNESS (CAB) WIRING CONNECTOR

3 - CAB MOUNTED TO ICU

Lift ICU off frame rail bolts and remove from vehicle.
If CAB and HCU need to be separated, (Refer to BRAKES/HYDRAULIC/MECHANICAL/ICU (INTEGRATED CONTROL UNIT - DISASSEMBLY)