brake fluid YAMAHA YZ426F 2000 Owners Manual

SPEC
2 - 14
MAINTENANCE SPECIFICATIONS
Wheel:
Front wheel type Spoke wheel ----
Rear wheel type Spoke wheel ----
Front rim size/material 21 ´ 1.60/Aluminum ----
Rear rim size/material 19 ´ 2.15/Aluminum ----
Rim runout limit:
Radial ---- 2.0 mm (0.08 in)
Lateral ---- 2.0 mm (0.08 in)
Drive chain:
Type/manufacturer 520DM-DHA/DAIDO ----
Number of links 113 links + joint ----
Chain slack 40 ~ 50 mm (1.6 ~ 2.0 in) ----
Chain length (10 links) ----152.5 mm (6.00 in)
Front disc brake:
Disc outside dia. ´ Thickness 245 ´ 3.0 mm (9.65 ´ 0.12 in) 245 ´ 2.5 mm
(9.65 ´ 0.08 in)
Deflection limit ----0.15 mm (0.006 in)
Pad thickness 4.4 mm (0.17 in) 1 mm (0.04 in)
Master cylinder inside dia. 11.0 mm (0.433 in) ----
Caliper cylinder inside dia. 27.0 mm (1.063 in) ´ 2 ----
Brake fluid type DOT #4 ----
Rear disc brake:
Disc outside dia. ´ Thickness 240 ´ 4.0 mm (9.45 ´ 0.16 in) 240 ´ 3.5 mm
(9.45 ´ 0.14 in)
Deflection limit ----0.15 mm (0.006 in)
Pad thickness 6.4 mm (0.25 in) 1.0 mm (0.04 in)
Master cylinder inside dia. 12.7 mm (0.500 in) ----
Caliper cylinder inside dia. 27.0 mm (1.063 in) ´ 1 ----
Brake fluid type DOT #4 ----
Brake lever and brake pedal:
Brake lever position 82.5 mm (3.25 in) ----
Brake pedal height
(vertical height below footrest top)5 mm (0.20 in) ----
Clutch lever free play (at lever pivot) 2 ~ 4 mm (0.08 ~ 0.16 in) ----
Throttle grip free play 3 ~ 5 mm (0.12 ~ 0.20 in) ----Item Standard Limit

3 - 2
INSP
ADJ

MAINTENANCE INTERVALS
SHIFT FORK, SHIFT CAM, GUIDE BAR
Inspect
c
Inspect wear
ROTOR NUT
Retighten
cc
MUFFLER
Inspect
Clean
Replace
cc
cc
* Whichever comes first
CRANK
Inspect and clean
cc
CARBURETOR
Inspect, adjust and clean
cc
When using a high-pres-
sure washer, make sure
that water does not enter
the accelerator pump.
SPARK PLUG
Inspect and clean
Replace
cc
c
DRIVE CHAIN
Lubricate, slack, alignment
Replace
cc
c
Use chain lube
Chain slack: 40~50 mm
(1.6~2.0 in)
COOLING SYSTEM
Check coolant level and leakage
Check radiator cap operation
Replace coolant
Inspect hoses
cc
cc
c
Every two years
OUTSIDE NUTS AND BOLTS
Retighten
cc
Refer to “STARTING AND
BREAK-IN” section in the
CHAPTER 1.
AIR FILTER
Clean and lubricate
Replace
cc
c
Use foam air-filter oil
OIL STRAINER (frame)
Clean
c
FRAME
Clean and inspect
cc
FUEL TANK, COCK
Clean and inspect
cc
BRAKES
Adjust lever position and pedal height
Lubricate pivot point
Check brake disc surface
Check fluid level and leakage
Retighten brake disc bolts, caliper
bolts, master cylinder bolts and union
bolts
Replace pads
Replace brake fluid
c
c
c
c
cc
c
c
c
c
c
c
Every one year
FRONT FORKS
Inspect and adjust
Replace oil
Replace oil seal
c
cc
c
c
Suspension oil “01” ItemAfter
break-inEvery
race
Every
third
(or
500 km)Every
fifth
(or
1,000 km)
As re-
quiredRemarks
3

3 - 24
INSP
ADJ
CHASSIS/BRAKE SYSTEM AIR BLEEDING
EC360000
CHASSIS
EC361012
BRAKE SYSTEM AIR BLEEDING
WARNING
Bleed the brake system if:
lThe system has been disassembled.
lA brake hose has been loosened or
removed.
lThe brake fluid is very low.
lThe brake operation is faulty.
A dangerous loss of braking performance
may occur if the brake system is not prop-
erly bleed.
1. Remove:
lMaster cylinder cap
lDiaphragm
lProtector (rear brake)
2. Bleed:
lBrake fluid
Front
õRear
Air bleeding steps:
a. Add proper brake fluid to the reservoir.
b. Install the diaphragm. Be careful not to
spill any fluid or allow the reservoir to
overflow.
c. Connect the clear plastic tube 2 tightly
to the caliper bleed screw 1.
d. Place the other end of the tube into a
container.
e. Slowly apply the brake lever or pedal
several times.
f. Pull the lever in or push down on the
pedal. Hold the lever or pedal in position.
g. Loosen the bleed screw and allow the
lever or pedal to travel towards its limit.
h. Tighten the bleed screw when the lever
or pedal limit has been reached; then
release the lever or pedal.
T R..
Bleed screw:
6 Nm (0.6 m • kg, 4.3 ft • lb)
i. Repeat steps (e) to (h) until of the air
bubbles have been removed from the
system.

õ

3 - 25
INSP
ADJ
FRONT BRAKE ADJUSTMENT
3. Install:
lProtector (rear brake)
lDiaphragm
lMaster cylinder cap
NOTE:
If bleeding is difficult, it may be necessary to
let the brake fluid system stabilize for a few
hours. Repeat the bleeding procedure when
the tiny bubbles in the system have disap-
peared.
j. Add brake fluid to the level line on the
reservoir.
WARNING
Check the operation of the brake after
bleeding the brake system.
EC362031
FRONT BRAKE ADJUSTMENT
1. Check:
lBrake lever position a
Standard brake lever position a:
82.5 mm (3.25 in)
2. Adjust:
lBrake lever position
Loosen the locknuts 1, then adjust the
lever position by changing their tighten-
ing position.
3. Tighten:
lLocknut
CAUTION:
Be sure to tighten the locknuts, as it will
cause poor brake performance.
T R..7 Nm (0.7 m · kg, 5.1 ft · lb)

3 - 27
INSP
ADJ
FRONT BRAKE PAD INSPECTION AND REPLACEMENT
lLoosen the pad pin 2.
lRemove the brake hose holder 3 and cal-
iper 4 from the front fork.
lRemove the pad pin and brake pads 5.
lConnect the transparent hose 6 to the
bleed screw 7 and place the suitable con-
tainer under its end.
lLoosen the bleed screw and push the cali-
per piston in.
lTighten the bleed screw.
T R..
Bleed screw:
6 Nm (0.6 m • kg, 4.3 ft • lb)
lInstall the brake pads 8 and pad pin.
lInstall the brake hose holder 9 and cali-
per 0 and tighten the pad pin A.
T R..
Bolt (caliper):
23 Nm (2.3 m • kg, 17 ft • lb)
Pad pin:
18 Nm (1.8 m • kg, 13 ft • lb)
CAUTION:
Do not reuse the drained brake fluid.
NOTE:
lInstall the brake pads with their projec-
tions a into the caliper recesses b.
lTemporarily tighten the pad pin at this
point.
NOTE:
Fit the brake hose holder cut c over the
projection d on the front fork and clamp the
brake hose.

3 - 28
INSP
ADJ
REAR BRAKE PAD INSPECTION AND REPLACEMENT
3. Inspect:
lBrake fluid level
Refer to “BRAKE FLUID LEVEL
INSPECTION” section.
lInstall the pad pin plug B.
T R..
Pad pin plug:
3 Nm (0.3 m • kg, 2.2 ft • lb)
4. Check:
lBrake lever operation
A softy or spongy feeling ® Bleed
brake system.
Refer to “BRAKE SYSTEM AIR
BLEEDING” section.
EC366060
REAR BRAKE PAD INSPECTION AND
REPLACEMENT
1. Inspect:
lBrake pad thickness a
Out of specification ® Replace as a
set.
2. Replace:
lBrake pad
Brake pad thickness a:
Standard
6.4 mm (0.25 in) 1.0 mm (0.04 in)
Brake pad replacement steps:
lRemove the protector 1 and pad pin plug
2.
lLoosen the pad pin 3.
lRemove the rear wheel 4 and caliper 5.
Refer to “FRONT WHEEL AND REAR
WHEEL” section in the CHAPTER 5.

3 - 29
INSP
ADJ
REAR BRAKE PAD INSPECTION AND REPLACEMENT
lRemove the pad pin 6 and brake pads 7.
lConnect the transparent hose 8 to the
bleed screw 9 and place the suitable con-
tainer under its end.
lLoosen the bleed screw and push the cali-
per piston in.
lTighten the bleed screw.
T R..
Bleed screw:
6 Nm (0.6 m • kg, 4.3 ft • lb)
lInstall the brake pad 0 and pad pin A.
lInstall the caliper B and rear wheel C.
Refer to “FRONT WHEEL AND REAR
WHEEL” section in the CHAPTER 5.
lTighten the pad pin D.
T R..
Pad pin:
18 Nm (1.8 m • kg, 13 ft • lb)
lInstall the pad pin plug E and protector F.
T R..
Bolt (protector):
7 Nm (0.7 m • kg, 5.1 ft • lb)
CAUTION:
Do not reuse the drained brake fluid.
NOTE:
lInstall the brake pads with their projec-
tions a into the caliper recesses b.
lTemporarily tighten the pad pin at this
point.

3 - 30
INSP
ADJREAR BRAKE PAD INSULATOR INSPECTION/
BRAKE FLUID LEVEL INSPECTION
3. Inspect:
lBrake fluid level
Refer to “BRAKE FLUID LEVEL
INSPECTION” section.
4. Check:
lBrake pedal operation
A softy or spongy feeling ® Bleed
brake system.
Refer to “BRAKE SYSTEM AIR
BLEEDING” section.
EC36b000
REAR BRAKE PAD INSULATOR
INSPECTION
1. Remove:
lBrake pad
Refer to “REAR BRAKE PAD INSPEC-
TION AND REPLACEMENT” section.
2. Inspect:
lRear brake pad insulator 1
Damage ® Replace.
EC367001
BRAKE FLUID LEVEL INSPECTION
1. Place the master cylinder so that its top is
in a horizontal position.
2. Inspect:
lBrake fluid level
Fluid at lower level ® Fill up.
aLower level
Front
õRear
WARNING
lUse only designated quality brake fluid to
avoid poor brake performance.
lRefill with same type and brand of brake
fluid; mixing fluids could result in poor
brake performance.
lBe sure that water or other contaminants
do not enter master cylinder when refill-
ing.
lClean up spilled fluid immediately to
avoid erosion of painted surfaces or plas-
tic parts.
Recommended brake fluid:
DOT #4
õ

5 - 10
CHASFRONT BRAKE AND REAR BRAKE
EC5A0000
FRONT BRAKE AND REAR BRAKE
EC5A8000
FRONT BRAKE
Extent of removal:1 Brake hose removal2 Caliper removal
3 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.
Drain the brake fluid.
Refer to “REMOVAL POINTS”.
1 Hose cover 1
2 Brake hose holder 1
3 Bolt (brake hose holder) 2 Only loosening.
4 Union bolt 2
5 Brake hose 1
6 Pad pin plug 1 Remove when loosening the pad pin.
7 Pad pin 1 Loosen when disassembling the caliper.
8 Caliper 1
9 Brake lever 1
10 Master cylinder bracket 1
11 Master cylinder 1
WARNING
Support the machine securely so there is nodanger of it falling over.
2
3
1
3
2

5 - 11
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.
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
10 Master cylinder 1
WARNING
Support the machine securely so there is nodanger of it falling over.
3
1
321
FRONT BRAKE AND REAR BRAKE