2003 YAMAHA YZ85 boot

IMPORTANT NOTICE
THIS MACHINE IS DESIGNED STRICTLY
FOR COMPETITION USE, ONLY ON A
CLOSED COURSE. It is illegal for this
machine to be operated on any public street,
road, or highway. Off-road use on public lands
may also be illegal. Please check local regula-
tions before riding.
1. THIS MACHINE IS TO BE OPERATED
BY AN EXPERIENCED RIDER ONLY.
Do not attempt to operate this
machine at maximum power until you
are totally familiar with its character-
istics.
2. THIS MACHINE IS DESIGNED TO BE
RIDDEN BY THE OPERATOR ONLY.
Do not carry passengers on this
machine.
3. ALWAYS WEAR PROTECTIVE
APPAREL.
When operating this machine, always
wear an approved helmet with gog-
gles or a face shield. Also wear heavy
boots, gloves, and protective cloth-
ing. Always wear proper fitting cloth-
ing that will not be caught in any of
the moving parts or controls of the
machine.
4. ALWAYS MAINTAIN YOUR MACHINE
IN PROPER WORKING ORDER.
For safety and reliability, the machine
must be properly maintained. Always
perform the pre-operation checks
indicated in this manual. Correcting a
mechanical problem before you ride
may prevent an accident.
5. GASOLINE IS HIGHLY FLAMMABLE.
Always turn off the engine while refu-
eling. Take care to not spill any gaso-
line on the engine or exhaust system.
Never refuel in the vicinity of an open
flame, or while smoking.
SAFETY INFORMATION

5 - 11
CHAS
BRAKE CALIPER DISASSEMBLY
5PA50270
ÈFront
ÉRear
Extent of removal:
1 Front brake caliper disassembly
2 Rear brake caliper disassembly
Extent of removal Order Part name Q’ty Remarks
BRAKE CALIPER DISASSEM-
BLY
1 Brake pad 2
2 Brake caliper bracket 1
3 Brake caliper piston 2 Refer to “REMOVAL POINTS”.
4 Dust seal 2
Refer to “REMOVAL POINTS”.
5 Piston seal 2
6 Pin boot 1
7 Sleeve boot 1
8 Pad pin 2
9 Brake pad 2
0 Brake caliper piston 1 Refer to “REMOVAL POINTS”.
A Dust seal 1
Refer to “REMOVAL POINTS”.
B Piston seal
1
2
1
FRONT BRAKE AND REAR BRAKE

5 - 12
CHAS
BRAKE MASTER CYLINDER DISASSEMBLY
5PA50280
ÈFront
ÉRear
Extent of removal:
1 Front brake master cylinder disassembly
2 Rear brake master cylinder disassembly
Extent of removal Order Part name Q’ty Remarks
BRAKE MASTER CYLINDER
DISASSEMBLY
1 Brake master cylinder cap 1
2 Diaphragm 1
3 Brake master cylinder boot 1
4 Circlip 1 Use a long nose circlip pliers.
5 Washer 1
6 Push rod 1
7 Brake master cylinder kit
1
12
21
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 - 18
CHAS
2. Install:

Pin boot 1
On brake caliper 2.
NOTE:
Apply the lithium soap base grease on the pin
boot inner surface.
5PA50500
3. Install:

Brake caliper bracket 1

Bolt (brake caliper bracket) 2

Brake pad 3
5PA50510
T R..30 Nm (3.0 m · kg, 22 ft · lb)
4. Install:

Brake caliper 1
NOTE:

Apply the lithium soap base grease on the
guide pin 2.

Install the brake caliper into the guide pin
and turn it clockwise.
5PA50520
5. Install:

Brake caliper support bolt 1
NOTE:
Apply the lithium soap base grease on the
brake caliper support bolt.
Rear brake caliper
1. Install:

Pad support 1

Brake pad 2

Pad pin 3
NOTE:

Install the brake pad fitted with brake pad
shim 4 on the brake caliper piston side.

Temporarily tighten the pad pins at this point.
5PA50530
T R..23 Nm (2.3 m · kg, 17 ft · lb)
5PA50540
FRONT BRAKE AND REAR BRAKE

5 - 20
CHAS
4. Install:
[Front]

Brake master cylinder kit 1

Washer 2

Circlip 3

Brake master cylinder boot 4
To brake master cylinder 5.
[Rear]

Brake master cylinder kit 1

Push rod 2

Circlip 3

Brake master cylinder boot 4
To brake master cylinder 5.
NOTE:

Apply the brake fluid on the brake master cyl-
inder kit.

Apply the lithium soap base grease on the tip
of the push rod.

When installing the circlip, use a long nose
circlip pliers.
ÈFront
ÉRear
È
5PA50590
É
5PA50600
Front brake master cylinder
1. Install:

Brake master cylinder 1

Brake master cylinder bracket 2

Bolt (brake master cylinder bracket) 3
NOTE:

Install the bracket so that the arrow mark
a
face upward.

First tighten the bolts on the upper side of the
brake master cylinder bracket, and then
tighten the bolts on the lower side.
T R..9 Nm (0.9 m · kg, 6.5 ft · lb)
5PA50610
FRONT BRAKE AND REAR BRAKE