warning YAMAHA YZ85 2003 Owner's Manual

5 - 9
CHASFRONT BRAKE AND REAR BRAKE
EC5A0000
FRONT BRAKE AND REAR BRAKE
EC5A8000
FRONT BRAKE
5PA50250
Extent of removal:
1 Brake hose removal
2 Brake caliper removal
3 Brake master cylinder removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removalFRONT BRAKE REMOVAL
Hold the machine by placing the
suitable stand under the engine.
WARNING
Support the machine securely so there is no
danger of it falling over.
Drain the brake fluid. Refer to “REMOVAL POINTS”.
1 Protector 1
2 Brake hose holder 1
3 Union bolt 2
4 Brake hose 1
5 Brake caliper support bolt 1
6 Brake caliper 1 Refer to “REMOVAL POINTS”.
7Brake lever 1
8 Brake master cylinder bracket 1
9 Brake master cylinder 1
2
3
132

5 - 10
CHAS
EC5A8100
REAR BRAKE
5PAR0016
Extent of removal:
1 Brake caliper removal
2 Brake hose removal
3 Brake master cylinder removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removalREAR BRAKE REMOVAL
Hold the machine by placing the
suitable stand under the engine.
WARNING
Support the machine securely so there is no
danger of it falling over.
Drain the brake fluid. Refer to “REMOVAL POINTS”.
1 Protector 1
2 Pad pin 2 Loosen when disassembling the caliper.
3 Brake caliper 1
4 Brake hose holder 2
5 Union bolt 2
6 Brake hose 1
7 Brake pedal 1
8 Reservoir tank 1
9 Reservoir hose 1
10 Brake master cylinder 1
3
1
321
FRONT BRAKE AND REAR BRAKE

5 - 14
CHAS
Brake caliper piston
1. Remove:

Brake caliper piston
Use compressed air and proceed carefully.
WARNING

Cover piston with rag and use extreme
caution when expelling piston from cylin-
der.

Never attempt to pry out piston.
ÈFront
ÉRear
Caliper piston removal steps:

Insert a piece of rag into the brake caliper
to lock one brake caliper.

Carefully force the piston out of the brake
caliper cylinder with compressed air.
È
5PA50330
5PA50340
Brake caliper piston seal kit
1. Remove:

Dust seal 1

Piston seal 2
NOTE:
Remove the piston seals and dust seals by
pushing them with a finger.
CAUTION:
Never attempt to pry out piston seals and
dust seals.
WARNING
Replace the piston seals and dust seals
whenever a caliper is disassembled.
ÈFront
ÉRear
È
5PA50350
É
5PA50360
É
FRONT BRAKE AND REAR BRAKE

5 - 15
CHAS
EC5A4000
INSPECTION
Brake master cylinder
1. Inspect:

Brake master cylinder inner surface a
Wear/scratches → Replace master cylin-
der assembly.
Stains → Clean.
WARNING
Use only new brake fluid.
ÈFront
ÉRear
2. Inspect:

Diaphragm 1
Crack/damage → Replace.
ÈFront
ÉRear
È
É
5PA50370
È
É
5PA50380
3. Inspect:

Brake master cylinder piston 1

Brake master cylinder cup 2
Wear/damage/score marks → Replace
brake master cylinder kit.
ÈFront
ÉRear
É È
5PA50390
Brake caliper
1. Inspect:

Brake caliper cylinder inner surface a
Wear/score marks → Replace brake cali-
per assembly.
ÈFront
ÉRear
È
5PA50400
É
2. Inspect:

Brake caliper piston 1
Wear/score marks → Replace brake cali-
per piston assembly.
WARNING
Replace the piston seals and dust seals 2
whenever a caliper is disassembled.
5PA50410
FRONT BRAKE AND REAR BRAKE

5 - 16
CHAS
3. Inspect: (only front brake caliper)

Brake caliper bracket 1
Cranks/damage → Replace the brake cali-
per assembly.

Guide pin 2
Rust/damage → Replace the brake caliper
assembly.

Sleeve boot 3

Pin boot 4
Wear/damage → Replace.5PA50420
4. Inspect: (only front brake caliper)

Brake caliper support bolt 1
Scorches/rust/damage → Replace.
5PA50430
EC534301
Brake hose
1. Inspect:

Brake hose 1
Crack/damage → Replace.
5PA50440
EC5A5000
ASSEMBLY AND INSTALLATION
WARNING

All internal parts should be cleaned in
new brake fluid only.

Internal parts should be lubricated with
brake fluid when installed.

Replace the piston seals and dust seals
whenever a caliper is disassembled.
Brake caliper piston
1. Clean:

Brake caliper

Piston seal

Dust seal

Brake caliper piston
Clean them with brake fluid.
FRONT BRAKE AND REAR BRAKE

5 - 17
CHAS
2. Install:

Piston seal 1

Dust seal 2
WARNING
Always use new piston seals and dust
seals.
NOTE:
Fit the piston seals and dust seals onto the slot
on brake caliper correctly.
ÈFront
ÉRear
È
5PA50450
É
5PA50460
3. Install:

Brake caliper piston 1
NOTE:
Apply the brake fluid on the brake caliper pis-
ton wall.
CAUTION:

For the front brake caliper, install the pis-
ton with its shallow depressed side
a
facing the caliper. For the rear brake cali-
per, install the piston with its depressed
side
b facing the brake caliper.

Never force to insert.
ÈFront
ÉRear
È
5PA50470
É
5PA50480
Front brake caliper
1. Install:

Sleeve boot 1
On brake caliper bracket 2.
5PA50490
FRONT BRAKE AND REAR BRAKE

5 - 19
CHAS
2. Install:

Brake caliper 1

Bolt (brake caliper front side) 2

Bolt (brake caliper rear side) 3

Plate

Protector 4

Bolt (protector) 5
3. Tighten

Pad pin 6
Brake master cylinder kit
1. Clean:

Brake master cylinder

Brake master cylinder kit
Clean them with brake fluid.
5PA50550
T R..23 Nm (2.3 m · kg, 17 ft · lb)
T R..23 Nm (2.3 m · kg, 17 ft · lb)
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
T R..18 Nm (1.8 m · kg, 13 ft · lb)
2. Install:

Brake master cylinder cup (primary) 1

Brake master cylinder cup (secondary) 2
To brake master cylinder piston 3.
NOTE:
Apply the brake fluid on the brake master cylin-
der cup.
WARNING
After installing, cylinder cup should be
installed as shown direction. Wrong instal-
lation cause improper brake performance.
ÈFront
ÉRear
ÈÉ
5PA50560
ÈÉ
5PA50570
3. Install:

Spring 1
To brake master cylinder piston 2.
NOTE:
Install the spring at the smaller dia. side.
ÈFront
ÉRear
ÈÉ
5PA50580
FRONT BRAKE AND REAR BRAKE

5 - 22
CHAS
Front brake hose
1. Install:

Copper washer 1

Brake hose 2

Union bolt 3
WARNING
Always use new copper washers.
CAUTION:
Install the brake hose so that its pipe por-
tion a directs as shown and lightly
touches the projection b on the brake
master cylinder.
5PA50660
T R..30 Nm (3.0 m · kg, 22 ft · lb)
5PA50670
2. Install:

Protector 1

Bolt (protector) 2
NOTE:
Fit the brake hose into the guides a of the pro-
tector.
5PA50680
T R..7 Nm (0.7 m · kg, 5.1 ft · lb)
3. Install:

Brake hose holder 1

Bolt (brake hose holder) 2
NOTE:

Align the brake hose holder with the projec-
tion a on the front fork and clamp the brake
hose.

Pass the brake hose behind the rib b on the
front fork.
5PA50690
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
FRONT BRAKE AND REAR BRAKE

5 - 23
CHAS
4. Install:

Copper washer 1

Brake hose 2

Union bolt 3
WARNING
Always use new copper washers.
CAUTION:
Install the brake hose so that its pipe por-
tion a lightly touches the projection b on
the brake caliper.
5PA50700
5PA50710
T R..26 Nm (2.6 m · kg, 19 ft · lb)
Rear brake hose
1. Install:

Copper washer 1

Brake hose 2

Union bolt 3
WARNING
Always use new copper washers.
CAUTION:
Install the brake hose so that its pipe por-
tion a directs as shown and lightly
touches the projection b on the brake
master cylinder.
5PA50720
5PA50730
T R..26 Nm (2.6 m · kg, 19 ft · lb)
FRONT BRAKE AND REAR BRAKE

5 - 24
CHAS
2. Install:

Copper washer 1

Brake hose 2

Union bolt 3
WARNING
Always use new copper washers.
CAUTION:
Install the brake hose so that its pipe por-
tion a lightly touches the projection b on
the brake caliper.
5PA50740
5PA50750
T R..26 Nm (2.6 m · kg, 19 ft · lb)
3. Install:

Brake hose holder 1

Screw (brake hose holder) 2
5PA50760
T R..1 Nm (0.1 m · kg, 0.7 ft · lb)
FRONT BRAKE AND REAR BRAKE