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Hydraulic Control Assembly - Antilock Brakes

Brakes and Traction Control › Antilock Brakes / Traction Control Systems
Unified entry — merged from multiple cross-listed pages in the original manual.

Labor

Replace — Hydraulic Unit1.6 hr
Warranty 0.0 hrSkill B
Replace — Hydraulic Unit1.6 hr
Warranty 0.0 hrSkill B
Procedures
Overhaul — Hydraulic Control unit (HCU) - Disassembly3 steps
△ CAUTION
When removing ABM from HCU, be sure to completely separate the two components (approximately 38 mm (1.5 inches)) before removing ABM. Otherwise, damage to the pressure sensor will result requiring HCU replacement.
Fig. 1
Fig. 1
Fig. 2
Fig. 2
Fig. 3
Fig. 3
  1. If the mounting bracket (2) needs to be removed from the HCU, loosen the two mounting nuts (1), then slide the mounting bracket off the two grommets and mounting pin (3).
  2. Remove four screws (1) attaching antilock brake module (ABM) (2) to hydraulic control unit (HCU).
  3. Slide ABM (1) off HCU (2).
Overhaul — Hydraulic Control unit (HCU) - Assembly5 steps
△ CAUTION
Inspect seal around mating edge of ABM to ensure seal is in good shape.
△ CAUTION
When installing ABM to HCU, care must be taken not to damage the pressure sensor. If damaged, HCU replacement is necessary.
Fig. 1
Fig. 1
Fig. 2
Fig. 2
Fig. 3
Fig. 3
  1. Clean any debris off the mating surfaces of the antilock brake module (ABM) and hydraulic control unit (HCU).
  2. Align ABM (1) solenoids and pump/motor wiring with HCU (2) valves and wiring passage. Slide ABM onto HCU.
  3. Install four screws (1) attaching ABM to HCU. Tighten mounting screws to 6 Nm (53 in. lbs.).
  4. If the mounting bracket (2) needs to be installed on the HCU, slide the mounting bracket grommet over the mounting pin (3) and two grommet cutouts over the grommets on the HCU mounted studs. Tighten the mounting nuts to 8 Nm (71 in. lbs.)
  5. Install the HCU in the vehicle. Hydraulic Control unit (HCU) - Installation
Hydraulic Control unit (HCU) - Installation6 steps
Fig. 1
Fig. 1
Fig. 2
Fig. 2
  1. Install ABM (2) on the mounting bracket rubber pockets (1).
  2. Install brake lines to the ABM (2) and tighten to 20 Nm (180 in. lbs.).
  3. Install wiring harness connector to the ABM and push down on the release to secure the connector.
  4. Install negative battery cable to the battery.
  5. Bleed ABS brake system Service and Repair.
  6. Connect the scan tool and initialize the ABM by performing the ABS Verification Test ABS Verification Test.
Hydraulic Control unit (HCU) - Removal5 steps
Fig. 1
Fig. 1
Fig. 2
Fig. 2
  1. Install prop rod on the brake pedal to keep pressure on the brake system.
  2. Remove negative battery cable from the battery.
  3. Pull up on the ICU harness connector release and remove connector.
  4. Remove brake lines (1) from the ICU (2).
  5. Remove the bolt attaching the bracket to the ICU unit (2) by pulling the unit from the bracket (1).
Overhaul — Hydraulic Control unit (HCU) - Disassembly3 steps
△ CAUTION
When removing ABM from HCU, be sure to completely separate the two components (approximately 38 mm (1.5 inches)) before removing ABM. Otherwise, damage to the pressure sensor will result requiring HCU replacement.
Fig. 1
Fig. 1
Fig. 2
Fig. 2
Fig. 3
Fig. 3
  1. If the mounting bracket (2) needs to be removed from the HCU, loosen the two mounting nuts (1), then slide the mounting bracket off the two grommets and mounting pin (3).
  2. Remove four screws (1) attaching antilock brake module (ABM) (2) to hydraulic control unit (HCU).
  3. Slide ABM (1) off HCU (2).
Overhaul — Hydraulic Control unit (HCU) - Assembly5 steps
△ CAUTION
Inspect seal around mating edge of ABM to ensure seal is in good shape.
△ CAUTION
When installing ABM to HCU, care must be taken not to damage the pressure sensor. If damaged, HCU replacement is necessary.
Fig. 1
Fig. 1
Fig. 2
Fig. 2
Fig. 3
Fig. 3
  1. Clean any debris off the mating surfaces of the antilock brake module (ABM) and hydraulic control unit (HCU).
  2. Align ABM (1) solenoids and pump/motor wiring with HCU (2) valves and wiring passage. Slide ABM onto HCU.
  3. Install four screws (1) attaching ABM to HCU. Tighten mounting screws to 6 Nm (53 in. lbs.).
  4. If the mounting bracket (2) needs to be installed on the HCU, slide the mounting bracket grommet over the mounting pin (3) and two grommet cutouts over the grommets on the HCU mounted studs. Tighten the mounting nuts to 8 Nm (71 in. lbs.)
  5. Install the HCU in the vehicle. Hydraulic Control unit (HCU) - Installation
Hydraulic Control unit (HCU) - Installation6 steps
Fig. 1
Fig. 1
Fig. 2
Fig. 2
  1. Install ABM (2) on the mounting bracket rubber pockets (1).
  2. Install brake lines to the ABM (2) and tighten to 20 Nm (180 in. lbs.).
  3. Install wiring harness connector to the ABM and push down on the release to secure the connector.
  4. Install negative battery cable to the battery.
  5. Bleed ABS brake system Service and Repair.
  6. Connect the scan tool and initialize the ABM by performing the ABS Verification Test ABS Verification Test.
Hydraulic Control unit (HCU) - Removal5 steps
Fig. 1
Fig. 1
Fig. 2
Fig. 2
  1. Install prop rod on the brake pedal to keep pressure on the brake system.
  2. Remove negative battery cable from the battery.
  3. Pull up on the ICU harness connector release and remove connector.
  4. Remove brake lines (1) from the ICU (2).
  5. Remove the bolt attaching the bracket to the ICU unit (2) by pulling the unit from the bracket (1).
Factory service manual
From the 2008 KK factory manual — descriptions, specs, torque & procedures for this part.
HYDRAULIC CONTROL UNIT
The HCU consists of a valve body, pump motor, and pressure sensor.
HYDRAULIC CONTROL UNIT
Accumulators in the valve body store extra fluid released to the system for ABS mode operation. The pump is used to clear the accumulators of brake fluid and is operated by a DC type motor. The motor is controlled by the
HYDRAULIC CONTROL UNIT📷 1
1. Install prop rod on the brake pedal to keep pressure on the brake system. 2. Remove negative battery cable from the battery. 3. Pull up on the ICU harness connector release and remove connector.
4. Remove brake lines (1) from the ICU (2).
5. Remove the bolt attaching the bracket to the ICU unit (2) by pulling the unit from the bracket (1).
figure
HYDRAULIC CONTROL UNIT📷 2
1. If the mounting bracket (2) needs to be removed from the HCU, loosen the two mounting nuts (1), then slide the mounting bracket off the two grommets and mounting pin (3).
2. Remove four screws (1) attaching antilock brake module (ABM) (2) to hydraulic control unit (HCU).
CAUTION: When removing ABM from HCU, be sure to completely separate the two components (approximately 38 mm (1.5 inches)) before removing ABM. Otherwise, damage to the pressure sensor will result requiring HCU replacement.
3. Slide ABM (1) off HCU (2).
figure
figure
HYDRAULIC CONTROL UNIT📷 2
CAUTION: Inspect seal around mating edge of ABM to ensure seal is in good shape.
1. Clean any debris off the mating surfaces of the antilock brake module (ABM) and hydraulic control unit
figure
figure
(HCU).📷 2
CAUTION: When installing ABM to HCU, care must be taken not to damage the pressure sensor. If damaged, HCU replacement is necessary.
2. Align ABM (1) solenoids and pump/motor wiring with HCU (2) valves and wiring passage. Slide ABM onto HCU.
3. Install four screws (1) attaching ABM to HCU. Tighten mounting screws to 6 N.m (53 in. lbs.).
4. If the mounting bracket (2) needs to be installed on the HCU, slide the mounting bracket grommet over the mounting pin (3) and two grommet cutouts over the grommets on the HCU mounted studs. Tighten the mounting nuts to 8 N.m (71 in. lbs.) 5. Install the HCU in the vehicle. Refer to INSTALLATION.
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HYDRAULIC CONTROL UNIT📷 3
NOTE: If the ABM module is being replaced with a new ABM module it must be
reprogrammed with the use of a scan tool.
1. Install ABM (2) on the mounting bracket rubber pockets (1).
2.   Install brake lines to the ABM (2) and tighten to 20 N.m (180 in. lbs.).
3.   Install wiring harness connector to the ABM and push down on the release to secure the connector.
4.   Install negative battery cable to the battery.
5.   Bleed ABS brake system. See STANDARD PROCEDURE.
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