Yamaha Wr 450 F Owners Manual

5 - 16
CHASFRONT BRAKE AND REAR BRAKE
EC533402
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.
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.
ÅFront
ıRear
Å
ı
EC5A4000
INSPECTION
EC534112
Master cylinder
1. Inspect:
Master cylinder inner surface a 
Wear/scratches → Replace master cyl-
inder assembly.
Stains →...

5 - 17
CHAS
EC534214
Caliper
1. Inspect:
Caliper cylinder inner surface a 
Wear/score marks → Replace caliper
assembly.
ÅFront
ıRear
ı Å
2. Inspect:
Caliper 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:
Brake hose 1 
Crack/damage → Replace.
EC5A5000
ASSEMBLY AND INSTALLATION
WARNING
All internal parts should be cleaned in
new brake fluid only.
Internal parts should be...

5 - 18
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 caliper correctly.
ÅFront
ıRear
Å
New
New
ı
3. Install:
Caliper piston 1 
NOTE:
Apply the brake fluid on the piston wall.
ACHTUNG:CAUTION:
Install the piston with its shallow
depressed side a facing the caliper.
Never force to insert.
ÅFront
ıRear
EC5A5700
Front caliper
1. Install:
Pad support 1 
Brake pad 2 
Pad pin 3 
NOTE:
Install...

5 - 19
CHASFRONT BRAKE AND REAR BRAKE
2. Install:
Copper washer 1
Union bolt 2 
WARNING
Always use new copper washers.
ACHTUNG:CAUTION:
Install the brake hose so that its pipe por-
tion a directs as shown and lightly
touches the projection b on the caliper.
New
T R..30 Nm (3.0 m · kg, 22 ft · lb)
3. Install:
Brake hose holder 1 
Caliper 2 
Bolt (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:
Pad pin 4 
5. Install:...

5 - 20
CHASFRONT BRAKE AND REAR BRAKE
2. Install:
Disc cover 1 
Bolt (disc cover) 2 
T R..7 Nm (0.7 m · kg, 5.1 ft · lb)
3. Install:
Caliper 1 
Rear wheel 2 
Refer to “FRONT WHEEL AND REAR
WHEEL” section.
4. Tighten:
Pad pin 3 
5. Install:
Pad pin plug 4 
Master cylinder kit
1. Clean:
Master cylinder
Master cylinder kit
Clean them with brake fluid.
T R..18 Nm (1.8 m · kg, 13 ft · lb)
T R..3 Nm (0.3 m · kg, 2.2 ft · lb)
2. Install:
Master cylinder cup (primary) 1 
Master cylinder cup (secondary)...

 
5 - 21
CHAS
 
FRONT BRAKE AND REAR BRAKE 
3. Install: 
 
Spring   
1  
 
To master cylinder piston   
2  
.
NOTE:
 
Install the spring at the smaller dia. side. 
Å  
Front  
ı  
Rear
Åı
 
4. Install:
[Front] 
 
Master cylinder kit   
1  
  
 
Plain washer   
2  
  
 
Circlip   
3  
  
 
Master cylinder boot   
4  
 
To master cylinder   
5  
.
[Rear] 
 
Master cylinder kit   
1  
  
 
Push rod   
2  
  
 
Circlip   
3  
  
 
Master cylinder boot   
4  
 
To master cylinder   
5  
.
NOTE:
 
...

 
5 - 22
CHAS
 
FRONT BRAKE AND REAR BRAKE 
2. Install: 
 
Brake lever  
1 
  
 
Bolt (brake lever)  
2 
  
 
Nut (brake lever)  
3 
 
NOTE:
 
Apply the lithium soap base grease on the
brake lever sliding surface, bolt and contacting 
surface of the master cylinder piston. 
Rear master cylinder 
1. Install: 
 
Copper washer  
1 
  
 
Brake hose  
2 
  
 
Union bolt  
3 
 
WARNING
 
Always use new copper washers.
ACHTUNG:CAUTION:
 
Install the brake hose so that its pipe por-
tion  
a 
 directs as...

5 - 23
CHASFRONT BRAKE AND REAR BRAKE
4. Install:
Pin 1 
Plain washer 2 
Cotter pin 3 
NOTE:
After installing, check the brake pedal height.
Refer to “REAR BRAKE ADJUSTMENT” sec-
tion in the CHAPTER 3.
New
Front brake hose
1. Install:
Brake hose 1 
To brake hose holder 2.
NOTE:
Before tightening the bolt (brake hose holder),
align the top a of the brake hose neck with the
brake hose holder bottom b. Then pass the
brake hose in front of the axle boss c and fit it
into the hose groove d so that the...

5 - 24
CHASFRONT BRAKE AND REAR BRAKE
4. Install:
Copper washer 1 
Brake hose 2 
Union bolt 3 
WARNING
Always use new copper washers.
ACHTUNG:CAUTION:
Install the brake hose so that it contacts
the master cylinder projection a and that
its bent portion b faces downward.
New
T R..30 Nm (3.0 m · kg, 22 ft · lb)
Rear brake hose
1. Install:
Copper washer 1 
Brake hose 2 
Union bolt 3 
WARNING
Always use new copper washers.
ACHTUNG:CAUTION:
Install the brake hose so that its pipe por-
tion a directs as...

5 - 25
CHASFRONT BRAKE AND REAR BRAKE
2. Install:
Brake hose holder 1 
Screw (brake hose holder) 2 
ACHTUNG: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..1 Nm (0.1 m · kg, 0.7 ft · lb)
Brake fluid
1. Fill:
Brake fluid
Until the fluid level reaches “LOWER”
level line a.
WARNING
Use only the designated quality brake
fluid:
otherwise, the rubber seals may deterio-
rate, causing leakage and...