brake YAMAHA YZ426F 2000 Service Manual

5 - 14
CHASFRONT BRAKE AND REAR BRAKE
EC5A3000
REMOVAL POINTS
EC5A3100
Brake fluid
1. Remove:
[Front]
lMaster cylinder cap 1
[Rear]
lMaster cylinder guard 1
lReservoir tank cap 2
NOTE:
Do not remove the diaphragm.
Front
õRear
2. Connect the transparent hose 1 to the
bleed screw 2 and place a suitable con-
tainer under its end.
Front
õRear
3. Loosen the bleed screw and drain the
brake fluid while pulling the lever in or
pushing down on the pedal.
ACHTUNG:CAUTION:
lDo not reuse the drained brake fluid.
lBrake fluid may erode painted surfaces or
plastic parts. Always clean up spilled
fluid immediately.

õ
õ
EC533301
Caliper piston
1. Remove:
lCaliper piston
Use compressed air and proceed care-
fully.
WARNING
lCover piston with rag and use extreme
caution when expelling piston from cylin-
der.
lNever attempt to pry out piston.
Front
õRear
Caliper piston removal steps:
lInsert a piece of rag into the caliper to lock
one caliper.
lCarefully force the piston out of the caliper
cylinder with compressed air.

õ

5 - 15
CHASFRONT BRAKE AND REAR BRAKE
EC533402
Piston seal kit
1. Remove:
lDust seal 1
lPiston seal 2
NOTE:
Remove the piston seals and dust seals by
pushing them with a finger.
ACHTUNG:CAUTION:
Never attempt to pry out piston seals and
dust seals.
WARNING
Replace the piston seals and dust seals
whenever a caliper is disassembled.
Front
õRear
õ
EC5A4000
INSPECTION
EC534112
Master cylinder
1. Inspect:
lMaster cylinder inner surface a
Wear/scratches ® Replace master cyl-
inder assembly.
Stains ® Clean.
WARNING
Use only new brake fluid.
Front
õRear
2. Inspect:
lDiaphragm 1
Crack/damage ® Replace.
Front
õRear
õ

õ

3. Inspect:
lMaster cylinder piston 1
lMaster cylinder cup 2
Wear/damage/score marks ® Replace
master cylinder kit.
Front
õRear
õ

5 - 16
CHAS
EC534214
Caliper
1. Inspect:
lCaliper cylinder inner surface a
Wear/score marks ® Replace caliper
assembly.
Front
õRear
õ
2. Inspect:
lCaliper piston 1
Wear/score marks ® Replace caliper
piston assembly.
WARNING
Replace the piston seals and dust seals 2
whenever a caliper is disassembled.
EC534301
Brake hose
1. Inspect:
lBrake hose 1
Crack/damage ® Replace.
EC5A5000
ASSEMBLY AND INSTALLATION
WARNING
lAll internal parts should be cleaned in
new brake fluid only.
lInternal parts should be lubricated with
brake fluid when installed.
lReplace the piston seals and dust seals
whenever a caliper is disassembled.
EC5A5800
Caliper piston
1. Clean:
lCaliper
lPiston seal
lDust seal
lCaliper piston
Clean them with brake fluid.
FRONT BRAKE AND REAR BRAKE

5 - 17
CHAS
2. Install:
lPiston seal 1
lDust seal 2
WARNING
Always use new piston seals and dust
seals.
NOTE:
Fit the piston seals and dust seals onto the slot
on caliper correctly.
Front
õRear

New
New
õ
3. Install:
lCaliper piston 1
NOTE:
Apply the brake fluid on the piston wall.
ACHTUNG:CAUTION:
lFor the front caliper, install the piston
with its depressed side a facing the cali-
per. For the rear caliper, install the piston
with its shallow depressed side b facing
the caliper.
lNever force to insert.
Front
õRear

õ
EC5A5700
Front caliper
1. Install:
lPad support 1
lBrake pad 2
lPad pin 3
NOTE:
lInstall the brake pads with their projections
a into the caliper recesses b.
lTemporarily tighten the pad pin at this point.
FRONT BRAKE AND REAR BRAKE

5 - 18
CHASFRONT BRAKE AND REAR BRAKE
2. Install:
lCopper washer 1
lUnion bolt 2
WARNING
Always use new copper washers.
ACHTUNG:CAUTION:
Install the brake hose so that its pipe por-
tion a directs as show and lightly touches
the projection b on the caliper.
New
T R..30 Nm (3.0 m · kg, 22 ft · lb)
3. Install:
lBrake hose holder 1
lCaliper 2
lBolt (caliper) 3
NOTE:
Fit the brake hose holder cut a over the pro-
jection b on the front fork and clamp the brake
hose.
4. Tighten:
lPad pin 4
5. Install:
lPad pin plug 5
T R..23 Nm (2.3 m · kg, 17 ft · lb)
T R..18 Nm (1.8 m · kg, 13 ft · lb)
T R..3 Nm (0.3 m · kg, 2.2 ft · lb)
EC5A5100
Rear caliper
1. Install:
lPad support 1
lBrake pad 2
lPad pin 3
NOTE:
lInstall the brake pads with their projections
a into the caliper recesses b.
lTemporarily tighten the pad pin at this point.

5 - 19
CHASFRONT BRAKE AND REAR BRAKE
2. Install:
lBrake disc protector 1
lBolt (protector) 2
T R..7 Nm (0.7 m · kg, 5.1 ft · lb)
3. Install:
lCopper washer 1
lBrake hose 2
lUnion bolt 3
WARNING
Always use new copper washers.
ACHTUNG:CAUTION:
Install the brake hose to the caliper with the
paint a on the pipe facing the caliper and
with the pipe contacting the caliper projec-
tion b.
New
T R..30 Nm (3.0 m · kg, 22 ft · lb)
4. Install:
lCaliper 1
lRear wheel 2
Refer to “FRONT WHEEL AND REAR
WHEEL” section.
5. Tighten:
lPad pin 3
6. Install:
lPad pin plug 4
T R..18 Nm (1.8 m · kg, 13 ft · lb)
T R..3 Nm (0.3 m · kg, 2.2 ft · lb)

5 - 20
CHASFRONT BRAKE AND REAR BRAKE
EC5A5200
Master cylinder kit
1. Clean:
lMaster cylinder
lMaster cylinder kit
Clean them with brake fluid.
2. Install:
lMaster cylinder cup (primary) 1
lMaster cylinder cup (secondary) 2
To master cylinder piston 3.
NOTE:
Apply the brake fluid on the master cylinder
cup.
WARNING
After installing, cylinder cup should be
installed as shown direction. Wrong instal-
lation cause improper brake performance.
Front
õRear
õ
õ
3. Install:
lSpring 1
To master cylinder piston 2.
NOTE:
Install the spring at the smaller diameter side.
Front
õRear
õ

5 - 21
CHAS

FRONT BRAKE AND REAR BRAKE
4. Install:
[Front]
l
Master cylinder kit
1

l
Push rod
2

l
Plain washer
3

l
Circlip
4

l
Master cylinder boot
5

l
Locknut
6

To master cylinder
7
.
[Rear]
l
Master cylinder kit
1

l
Push rod
2

l
Circlip
3

l
Master cylinder boot
4

l
Locknut
5

To master cylinder
6
.
NOTE:

l
Apply the brake fluid on the master cylinder
kit.
l
Apply the lithium soap base grease on the tip
of the push rod.
l
When installing the circlip, use a long nose
circlip pliers.

Front
õ
Rear
EC5A5300
Front master cylinder
1. Install:
l
Master cylinder
1

l
Master cylinder bracket
2

l
Bolt (master cylinder bracket)
3

NOTE:

l
Install the bracket so that the arrow mark
a
face upward.
l
First tighten the bolts on the upper side of the
master cylinder bracket, and then tighten the
bolts on the lower side.
WARNING

Install the master cylinder so that the gaps
b
and
c
between the bolt (grip cap)
4
and
push rod
5
are equal. If you make a mis-
take in the master cylinder installation
position, the brake lever may contact the
grip cap, resulting in poor brake perfor-
mance.

õ
T R..9 Nm (0.9 m · kg, 6.5 ft · lb)

5 - 22
CHAS

FRONT BRAKE AND REAR BRAKE
2. Install:
l
Brake lever
1

l
Bolt (brake lever)
2

l
Nut (brake lever)
3

NOTE:

Apply the lithium soap base grease on the bolt.
T R..7 Nm (0.7 m · kg, 5.1 ft · lb)
T R..7 Nm (0.7 m · kg, 5.1 ft · lb)

3. Install:
l
Locknut
1

l
Circlip
2

NOTE:

l
Make sure the circlip is installed into the
groove
a
of the push rod.
l
After installing, check the brake lever posi-
tion. Refer to “FRONT BRAKE ADJUST-
MENT” section in the CHAPTER 3.
T R..7 Nm (0.7 m · kg, 5.1 ft · lb)
New
EC5A5400
Rear master cylinder
1. Install:
lReservoir hose 1
lReservoir tank 2
2. Install:
lMaster cylinder 1
lBolt (master cylinder) 2

5 - 23
CHASFRONT BRAKE AND REAR BRAKE
3. Install:
lSpring 1
lBrake pedal 2
lO-ring 3
lBolt (brake pedal) 4
lClip 5
NOTE:
lApply the lithium soap base grease on the
bolt, O-ring and brake pedal bracket.
lInstall the clip with its stopper portion a fac-
ing inward.
New
T R..19 Nm (1.9 m · kg, 13 ft · lb)
4. Install:
lPin 1
lPlain washer 2
lCotter pin 3
NOTE:
After installing, check the brake pedal height.
Refer to “REAR BRAKE ADJUSTMENT” sec-
tion in the CHAPTER 3.
New
EC5A5900
Front brake hose
1. Install:
lBrake hose 1
To brake hose holder 2.
NOTE:
Before tightening the bolt (brake hose holder),
pass the brake hose in front of the axle boss
a, then fit it into the hose groove b so that the
brake hose does not contact the nut (wheel
axle).
2. Install:
lHose cover 1
lPlain washer 2
lBolt [hose cover (M8)] 3
lBolt [hose cover (M6)] 4
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
T R..16 Nm (1.6 m · kg, 11 ft · lb)
T R..7 Nm (0.7 m · kg, 5.1 ft · lb)