2004 YAMAHA YZ85 brake

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 nodanger 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 - 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 Reservoir float 1
4 Brake master cylinder boot 1
5 Circlip 1 Use a long nose circlip pliers.
6 Washer 1
7 Push rod 1
8Brake master cylinder kit 1
1
2
21
FRONT BRAKE AND REAR BRAKE

5 - 13
CHAS
EC5A3000
REMOVAL POINTS
Brake fluid
1. Remove:
[Front]

Brake master cylinder cap 1
[Rear]

Reservoir tank cap 1
NOTE:
Do not remove the diaphragm.
ÈFront
ÉRear
È
5PA50290
É
5PA50300
2. Connect the transparent hose 2 to the
bleed screw 1 and place a suitable con-
tainer under its end.
ÈFront
ÉRear
3. Loosen the bleed screw and drain the
brake fluid while pulling the lever in or
pushing down on the pedal.
CAUTION:

Do not reuse the drained brake fluid.

Brake fluid may erode painted surfaces or
plastic parts. Always clean up spilled
fluid immediately.
ÈÉ
5PA50310
Front brake caliper
1. Remove:

Brake caliper 1
NOTE:
Turn the brake caliper counterclockwise and
pull out it from the guide pin 2 on the brake
caliper bracket.
5PA50320
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: (only front brake master cylinder)

Reservoir float 1
Damage → Replace.
5PA50380
4. 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
FRONT BRAKE AND REAR BRAKE

5 - 16
CHAS
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
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.
FRONT BRAKE AND REAR BRAKE

5 - 17
CHAS
Brake caliper piston
1. Clean:

Brake caliper

Piston seal

Dust seal

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