2001 YAMAHA WR 426F brake fluid

5 - 12
CHAS
EC5A8100
REAR BRAKE
Extent of removal:1 Caliper removal2 Brake hose removal
3 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.
Rear wheel Refer to “FRONT WHEEL AND REAR
WHEEL” section.
Drain the brake fluid. Refer to “REMOVAL POINTS”.
1 Pad pin plug 1 Remove when loosening the pad pin.
2 Pad pin 1 Loosen when disassembling the caliper.
3 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
10Master cylinder
1
3
1
321
FRONT BRAKE AND REAR BRAKE

5 - 15
CHASFRONT BRAKE AND REAR BRAKE
EC5A3000
REMOVAL POINTS
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 2 to the
bleed screw 1 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.
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 - 16
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.
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 - 17
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 - 18
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
FRONT BRAKE AND REAR BRAKE
3. Install:
lCaliper piston 1
NOTE:
Apply the brake fluid on the piston wall.
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
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.

õ

5 - 21
CHASFRONT BRAKE AND REAR BRAKE
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 dia. side.
Front
õRear
õ

5 - 22
CHASFRONT BRAKE AND REAR BRAKE
4. Install:
[Front]
lMaster cylinder kit 1
lPlain washer 2
lCirclip 3
lMaster cylinder boot 4
To master cylinder 5.
[Rear]
lMaster cylinder kit 1
lPush rod 2
lCirclip 3
lMaster cylinder boot 4
To master cylinder 5.
NOTE:
lApply the brake fluid on the master cylinder
kit.
lApply the lithium soap base grease on the tip
of the push rod.
lWhen installing the circlip, use a long nose
circlip pliers.
Front
õRear

õ
EC5A5310
Front master cylinder
1. Install:
lMaster cylinder 1
lMaster cylinder bracket 2
lBolt (master cylinder bracket) 3
NOTE:
lInstall the bracket so that the arrow mark a
face upward.
lFirst tighten the bolts on the upper side of the
master cylinder bracket, and then tighten the
bolts on the lower side.
T R..9 Nm (0.9 m · kg, 6.5 ft · lb)

5 - 26
CHASFRONT BRAKE AND REAR BRAKE
2. Install:
lBrake hose holder 1
lScrew (brake hose holder) 2
CAUTION:
After installing the brake hose holders,
make sure the brake hose does not contact
the spring (rear shock absorber). If it does,
correct its twist.
T R..4 Nm (0.4 m · kg, 2.9 ft · lb)
Brake fluid
1. Fill:
lBrake fluid
Until the fluid level reaches “LOWER”
level line a.
WARNING
lUse only the designated quality brake
fluid:
otherwise, the rubber seals may deterio-
rate, causing leakage and poor brake per-
formance.
lRefill with the same type of brake fluid;
mixing fluids may result in a harmful chem-
ical reaction and lead to poor performance.
lBe careful that water does not enter the
master cylinder when refilling. Water will
significantly lower the boiling point of the
fluid and may result in vapor lock.
CAUTION:
Brake fluid may erode painted surfaces or
plastic parts. Always clean up spilled fluid
immediately.
Front
õRear
Recommended brake fluid:
DOT #4

õ