1991 LEXUS SC400 brake

4. REMOVE SHOE RETURN SPRINGSUsing needle±nose pliers, remove the 2 shoe return springs.
5. REMOVE SHOE STRUT WITH SPRING
6. REMOVE FRONT SHOE ADJUSTER AND TENSION SPRING
(a) Slide out the front shoe and remove the shoe adjuster.
(b) Disconnect the tension spring and remove the front shoe.
7. REMOVE REAR SHOE
(a) Slide out the rear shoe.
(b) Remove the tension spring from the rear shoe.
(c) Disconnect the parking brake cable from the parking brake
shoe lever.
(d) Remove the shoe hold±down spring cups, springs and pins.
±
BRAKE SYSTEM REAR BRAKE (Parking Brake)BR±45
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PARKING BRAKE COMPONENTS
INSPECTION AND REPAIR
BR04G±0B
1. INSPECT DISASSEMBLED PARTSInspect the disassembled parts for wear, rust or damage.
2. MEASURE BRAKE SHOE LINING THICKNESS Using a scale, measure the thickness of the shoe lining.
Standard thickness:
2.5 mm (0.098 in.)
Minimum thickness: 1.0 mm (0.039 in.)
If the lining thickness is at the minimum thickness or less, or
if there is extremely uneven wear, replace the brake shoe.
3. MEASURE BRAKE DISC INSIDE DIAMETER Using a vernier caliper, measure the inside diameter of the
disc.
Standard inside diameter:
190 mm (7.48 in.)
Maximum inside diameter: 191 mm (7.52 in.)
Replace the disc if the inside di ameter is at the maximum val-
ue or more. Replace the disc or grind it with a lathe if the disc
is scored or is worn unevenly.
4. INSPECT P ARKING BRAKE LINING AND DISC FOR
PROPER CONTACT
Apply chalk to the inside surface of the disc, then grind down
the brake shoe lining to fit. If the contact between the disc and
the brake shoe lining is improper, repair it using a brake shoe
grinder or replace the brake shoe assembly.
5. MEASURE CLEARANCE BETWEEN PARKING BRAKE SHOE AND LEVER
Using a feeler gauge, measure the clearance.
Standard clearance:
Less than 0.35 mm (0.0138 in.)
If the clearance is not within the specification, replace the
shim with one of the correct size.
BR±46
±
BRAKE SYSTEM REAR BRAKE (Parking Brake)
WhereEverybodyKnowsYourName

 
Thickness mm(in.) Thickness mm(in.)
 0.3 (0.012) 0.9 (0.035)
 

0.6 

(0.024) 


 


6. IF NECESSARY, REPLACE SHIM
(a) Remove the parking brake shoe lever, and install the correct
size shim.
(b) Install the parking brake shoe lever with a new Cwasher.
(c) Remeasure the clearance.
PARKING BRAKE ASSEMBLY
BR0ES±04
HINT: Assemble the parts in the correct direction, as shown.
1. APPLY HIGH TEMPERATURE GREASE ON BACK± ING PLATE
±
BRAKE SYSTEM REAR BRAKE (Parking Brake)BR±47
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2. APPLY HIGH TEMPERATURE GREASE TO ADJUSTER
3. CONNECT PARKING BRAKE CABLE TO PARKINGBRAKE LEVER
(a) Install the shoe hold±down springs, cups and pins.
(b) Connect the parking brake cable to the parking brake shoe
lever of the rear shoe.
4. INSTALL REAR SHOE Slide in the rear shoe between the shoe hold±down spring
cup and the backing plate.
NOTICE: Do not allow oil or grease to get on the rubbing face.
5. INSTALL TENSION SPRING, FRONT SHOE ANDADJUSTER
(a) Install the tension spring on the rear shoe.
(b) Install the front shoe on the tension spring.
(c) Install the adjuster between the front and rear shoes.
(d) Slide in the front shoe between the shoe hold±down spring
cup and the backing plate.
BR±48
±
BRAKE SYSTEM REAR BRAKE (Parking Brake)
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6. INSTALL SHOE STRUT WITH SPRINGInstall the strut with the spring forward.
7. INSTALL SHOE RETURN SPRINGS Using needle±nose pliers, install the front shoe return spring
and then install the rear shoe return spring.
8. INSTALL DISC
(a) Before installing, polish the disc and shoe surfaces with sandpaper.
(b) Align the matchmarks and install the disc. HINT: If there are no matchmarks, temporarily install the disc,
then measure the disc runout and install the disc in the posi-
tion.
(See page BR±41)
9. ADJUST PARKING BRAKE SHOE CLEARANCE
(a) Temporarily install the hub nuts.
(b) Remove the hole plug.
(c) Turn the adjuster and expand the shoes until the disc locks.
(d) Return the adjuster 8 notches.
(e) Install the hole plug.
10. INSTALL REAR DISC BRAKE ASSEMBLY Install the disc brake assembly and torque the 2 mounting
bolts.
Torque: 104 N Vm (1,065 kgf Vcm, 77 ft Vlbf)
11. INSTALL REAR WHEEL
±
BRAKE SYSTEM REAR BRAKE (Parking Brake)BR±49
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12. SETTLING PARKING BRAKE SHOES AND DISC
(a) Drive the vehicle at about 50 km/h (31 mph) on a safe, leveland dry road.
(b) With the parking brake release button pushed in, pull on the
lever with 88 N (9 kgf, 19.8 lbf) of force.
(c) Drive the vehicle for about 400 meters (0.25 mile) in this condition.
(d) Repeat this procedure 2 or 3 times.
13. CHECK AND ADJUST PARKING BRAKE LEVER TRAVEL
BR±50
±
BRAKE SYSTEM REAR BRAKE (Parking Brake)
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PROPORTIONING AND BY±PASS
VALVE (P & B VALVE)
FLUID PRESSURE INSPECTION
BR0ET±01
1. INSTALL LSPV GAUGE (SST) AND BLEED AIRSST 09709±29017
2. RAISE MASTER CYLINDER PRESSURE AND CHECKREAR WHEEL CYLINDER PRESSURE
 Master cylinder pressure Rear wheel cylinder pressure
 1,961 kPa 1,961 kPa 

(20 kgf/cm2, 284 psi) 

(20 kgf/cm2, 284 psi)
 7,845 kPa5,492 kPa
 (80 kgf/cm2, 1,138 psi) (56 kgf/cm2, 796 psi)
Specifications: If the rear wheel cylinder pressure is in-
correct, replace the master cylinder.
3. BLEED BRAKE SYSTEM
4. CHECK FOR FLUID LEAKAGE
±
BRAKE SYSTEM PROPORTIONING AND BY±PASS VALVE (P & B
VALVE)BR±51
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ANTI±LOCK BRAKE SYSTEM (ABS)
BR0EU±04
DESCRIPTION

ABS is a brake system which controls the brake cylinder hydraulic pressure \
to all 4 wheels during sudden
braking and braking on slippery road surfaces, preventing the wheels from locki\
ng. ABS provides the
following benefits:
(1) Enables steering round an obstacle with a greater degree of certai\
nty even when panic braking.
(2) Enables stopping during panic braking while keeping the effect upon stability and steerability to a mini-
mum, even on curves.

In case a malfunction occurs, a diagnosis function and fail±safe system have been adopted for the ABS.
SYSTEM PARTS LOCATION
BR02L±05
BR±52±
BRAKE SYSTEM ANTI±LOCK BRAKE SYSTEM (ABS)
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