torque LEXUS SC400 1991 Service Manual PDF

TRAC CONTROL SYSTEM BLEEDING
BR0EE±03
1. BLEED TRACTION CONTROL SYSTEMCAUTION:
w The fluid is under high pressure, and could spray out with
great force, so exercise caution.
w When repairing the brake master cylinder or TRAC
system, bleed the air out of the TRAC system.
(a) Connect a vinyl tube to the bleeder plug of accumulator, then
loosen the bleeder plug.
(b) Start the engine to allow the TRAC pump motor to operate
until all the air has been bled out of the fluid.
(c) Tighten the bleeder plug and stop the engine.
Torque: 8.3 N Vm (85 kgf Vcm, 74 in. Vlbf)
(d) C onnect a vinyl tube to the bleeder plug of the TRAC
actuator, then loosen the bleeder plug.
(e) Start the engine to allow the TRAC pump motor to operate
until all the air has been bled out of the fluid.
(f) Tighten the bleeder plug and stop the engine. Torque: 8.3 N Vm (85 kgf Vcm, 74 in. Vlbf)
(g) Check if any diagnostic trouble code is output which indicates
trouble. If there is, clear the diagnostic trouble code.
2. CHECK FLUID LEVEL IN RESERVOIR Check the fluid level and add fluid if necessary.
Fluid:
SAE J1703 or FMVSS NO. 116DOT3
HINT: Add fluid with the engine idling.
BR±10
±
BRAKE SYSTEM CHECK AND ADJUSTMENT
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PARKING BRAKE CHECK AND
ADJUSTMENT
BR03R±04
1. CHECK THAT PARKING BRAKE LEVER TRAVEL IS
CORRECT
Pull the parking brake lever all the way up, and count the
number of clicks.
Parking brake lever travel at 196 N (20 kgf, 44.1 lbf):
5±8 clicks
If incorrect, adjust the parking brake.
2. IF NECESSARY, ADJUST PARKING BRAKE HINT: Before adjusting the parking brake, make sure that the
rear brake shoe clearance has been adjusted.
For shoe clearance adjustment, see page BR±49.
(a) Remove the cup holder.
(b) Using a socket driver and spanner wrench, remove the adjusting lock nut.
HINT: Tape the socket driver before use.
(c) Turn the adjusting nut until the lever travel is correct.
(d) Install the adjusting lock nut.
(e) Using a socket driver and s panner wrench, tighten the
adjusting lock nut.
Torque: 5.4 N Vm (55 kgf Vcm, 48 in. Vlbf)
(f) Install the cup holder.
±
BRAKE SYSTEM CHECK AND ADJUSTMENTBR±11
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MASTER CYLINDER ASSEMBLY
BR0EH±05
1. APPLY LITHIUM SOAP BASE GLYCOL GREASE TORUBBER PARTS INDICATED BY ARROWS
2. INSTALL PISTONS
NOTICE: Be careful not to damage the rubber lips on the pis-
tons.
(a) Insert the 2 pistons straight in, not at an angle.
NOTICE: If inserted at an angle, there is a possibility that the
cylinder bore could be damaged.
(b) Push in the piston with a screwdriver and install the snap ring
with snap ring pliers.
HINT: Tape the screwdriver tip before use.
3. w/ TRAC: INSTALL NO. 1 PISTON STOPPER BOLT
Using a screwdriver, push the piston in all the way and install
the No. 1 piston stopper bolt over a new gasket.
Torque: 10 N Vm (100 kgf Vcm, 7 ft Vlbf)
4. INSTALL NO. 2 PISTON STOPPER BOLT
Using a screwdriver, push the piston in all the way and install
the No. 2 piston stopper bolt over a new gasket.
Torque: 10 N Vm (100 kgf Vcm, 7 ft Vlbf)
5. INSTALL 2 GROMMETS
6. INSTALL RESERVOIR
(a) Install the strainer to the reservoir.
(b) Push the reservoir onto the cylinder.
(c) Install the set screw while pushing on the reservoir.
Torque: 1.7 N Vm (17.5 kgf Vcm, 15.2 in. Vlbf)
7. INSTALL RESERVOIR CAP
(a) Align the matchmark on the reservoir cap with the matchmark
on the ªopenº side of reservoir.
(b) Push down on the reservoir cap and turn it clockwise until it locks.
(c) Check that the matchmark on the reservoir cap is now aligned with the matchmark on the ªcloseº side of the
reservoir.
BR±16
±
BRAKE SYSTEM MASTER CYLINDER
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8. INSTALL MASTER CYLINDER BOOTWith the UP mark on the master cylinder boot facing up-
wards, install the cylinder boot on the master cylinder.
MASTER CYLINDER INSTALLATION
BR0EJ±05
1. ADJUST LENGTH OF BRAKE BOOSTER PUSH RODBEFORE INSTALLING MASTER CYLINDER
(See page
BR±19)
2. INSTALL MASTER CYLINDER Install the master cylinder and a new gasket on the brake
booster with 3 nuts.
Torque: 13 N Vm (130 kgf Vcm, 9 ft Vlbf)
3. CONNECT BRAKE LINES
Using SST, connect the brake lines to the master cylinder.
Torque the union nuts.
SST 09023±00100
Torque: 12 N Vm (125 kgf Vcm, 9 ft Vlbf)
4. CONNECT LEVEL WARNING SWITCH CONNECTOR
5. FILL BRAKE R ESERVOIR WITH BRAKE FLUID AND
BLEED BRAKE SYSTEM
(See page BR±8)
6. w/ TRAC:
BLEED TRAC SYSTEM
(See page BR±10)
7. CHECK FOR FLUID LEAKAGE
8. CHECK AND ADJUST BRAKE PEDAL (See page BR±7 )
±
BRAKE SYSTEM MASTER CYLINDERBR±17
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3. REMOVE BRAKE BOOSTER
(a) Remove the booster installation nuts.
(b) Remove the booster and gasket.
BRAKE BOOSTER INSTALLATION
BR03Z±08
1. INSTALL BRAKE BOOSTER
(a) Install the booster and gasket.
(b) Install and torque the booster installation nuts.
Torque: 12 NVm (125 kgf Vcm, 9 ft Vlbf)
(c) Insert the clevis pin into the clevis and brake pedal, and install
the clip to the clevis pin.
(d) Install the pedal return spring.
2. ADJUST LENGTH OF BOOSTER PUSH ROD
(a) Install the gasket on the master cylinder.
(b) Set the SST on the gasket, and lower the pin until its tip slightly touches the piston.
SST 09737±00010
(c) Turn the SST upside down, and set it on the booster. SST 09737±00010
(d) Measure the clearance between the booster push rod and
pin head (SST).
Clearance:
0 mm (0 in.)
(e) Adjust the booster push rod length until the push rod lightlytouches the pin head.
HINT: When adjusting the push rod, depress the brake pedal
enough so that the push rod sticks out.
3. INSTALL FOLLOWING PARTS: wVacuum hose
w Master cylinder
(See page BR±12)
w w/ TRAC:
TRAC pump assembly
(See page BR±162)
±
BRAKE SYSTEM BRAKE BOOSTERBR±19
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3. LIFT UP CALIPER
(a) Hold the sliding pin on the bottom and loosen the installationbolt.
(b) Remove the installation bolt.
(c) Lift up and suspend the caliper.
HINT: Do not disconnect the flexible hose from the caliper.
4. REMOVE FOLLOWING PARTS:
(a) 2 anti±squeal springs
(b) 2 brake pads
(c) 4 anti±squeal shims
(d) 4 pad support plates
5. CHECK DISC THICKNESS AND RUNOUT (See page BR±33 )
6. INSTALL UNDER SIDE PAD SUPPORT PLATES
7. INSTALL UPPER SIDE PAD SUPPORT PLATES
(a) Using cleaner, wipe off dust, water, oil, etc. from the pad support plate contact area of the torque plate.
(b) Remove the pad support cover sheets from new pad support plate.
BR±30
±
BRAKE SYSTEM FRONT BRAKE (SC400)
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(c) Install the new pad support plates.
8. INSTALL NEW PADS
(a) Apply disc brake grease to both sides of the inner anti±squeal
shim.
(b) Install the 2 anti±squeal shims on each pad.
(c) Install inner pad with the pad wear indicator plates facing downward.
(d) Install the outer pad.
NOTICE: There should be no oil or grease adhering to the fric-
tion surfaces of the pads or the disc.
(e) Install the 2 anti±squeal springs.
9. INSTALL CALIPER
(a) Draw out a small amount of brake fluid from the reservoir.
(b) P re ss in th e pisto n with wa te r pu mp plie rs or simila r
implement.
HINT: If the piston is difficult to push in, loosen the bleeder
plug and push in the piston while letting some brake fluid es-
cape.
(c) Install the caliper.
(d) Hold the sliding pin and torque the installation bolt.
Torque: 34 N Vm (350 kgf Vcm, 25 ft Vlbf)
10. INSTALL FRONT WHEEL
11. CHECK THAT FLUID LEVEL IS AT MAX LINE
CALIPER REMOVAL
BR042±0C
1. DISCONNECT FLEXIBLE HOSE
(a) Remove the union bolt and 2 gaskets from the caliper, then
disconnect the flexible hose from the caliper.
(b) Use a container to catch the brake fluid as it drains out.
±
BRAKE SYSTEM FRONT BRAKE (SC400)BR±31
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2. REMOVE CALIPER
(a) Hold the sliding pin and loosen the 2 installation bolts.
(b) Remove the 2 installation bolts.
(c) Remove the caliper from the torque plate.
3. REMOVE FOLLOWING PARTS:
(a) 2 anti±squeal springs
(b) 2 brake pads
CALIPER DISASSEMBLY
BR043±0B
1. REMOVE CYLINDER BOOT SET RINGS AND CYLINDERBOOT
Using a screwdriver, remove the 2 cylinder boot set rings and
cylinder boots from the caliper.
2. REMOVE PISTONS
(a) Place a piece of cloth or similar article between the piston and
the caliper.
(b) Use compressed air to remove the pistons from the caliper.
CAUTION: Do not place your fingers in front of the piston when
using compressed air.
3. REMOVE PISTON SEALS Using a screwdriver, remove the piston seal from the caliper.
BR±32
±
BRAKE SYSTEM FRONT BRAKE (SC400)
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4. REMOVE SLIDING PINS AND DUST BOOTS
(a) Remove the 2 sliding pins from the torque plate.
(b) Using a screwdriver and hammer, tap out the 2 dust boots.
FRONT BRAKE COMPONENTS
INSPECTION AND REPAIR
BR044±08
1. MEASURE PAD LINING THICKNESSUsing a ruler, measure the pad lining thickness.
Standard thickness:
11.0 mm (0.433 in.)
Minimum thickness: 1.0 mm (0.039 in.)
Replace the pad if the pad's thickness is at the minimum
thickness or less, or if the pad has severely uneven wear.
2. MEASURE DISC THICKNESS Using a micrometer, measure the disc thickness.
Standard thickness:
32 mm (1.260 in.)
Minimum thickness: 30 mm (1.181 in.)
Replace the disc if the thickness of the disc is at the minimum
thickness or less. Replace the disc or grind it on a lathe if it
is scored or is worn unevenly.
±
BRAKE SYSTEM FRONT BRAKE (SC400)BR±33
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3. MEASURE DISC RUNOUTUsing a dial indicator, measure the disc runout at a position
10 mm (0.39 in.) from the outside edge.
Maximum disc runout:
0.05 mm (0.0020 in.)
If the disc's runout is at the maximum value or greater, check
the bearing play in the axial direction and check the axle hub
runout (See page SA±30). If the bearing play and axle hub
runout are not abnormal, adjust the disc runout.
4. IF NECESSARY, ADJUST DISC RUNOUT
(a) Remove the 2 bolts and torque plate from the knuckle.
(b) Remove the hub nuts and the disc. Reinstall the disc 1/5 of a turn round from its original position on the hub. Install and
torque the hub nuts.
Torque: 103 N Vm (1,050 kgf Vcm, 76 ft Vlbf)
Remeasure the disc runout. Make a not of the runout and
disc's position on the hub.
(c) Repeat (b) until the disc has been install on the 3 remaining hub position.
(d) If the minimum runout recorded in (b) and (c) is less than 0.05
mm (0.0020 in.), install the disc in that position.
(e) If the minimum runout recorded in (b) and (c) is greater than
0.05 mm (0.0020 in.), replace the disc and repeat step 3.
(f) Install the torque plate and torque the 2 bolts.
Torque: 118 N Vm (1,200 kgf Vcm, 87 ft Vlbf)
CALIPER ASSEMBLY
BR045±0B
1. APPLY LITHIUM SOAP BASE GLYCOL GREASE TO
PARTS INDICATED WITH ARROWS
BR±34
±
BRAKE SYSTEM FRONT BRAKE (SC400)
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