Yamaha YFM660 01 User Manual

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CHASFRONT AND REAR BRAKES
3.Fill:

Brake fluid reservoir
CAUTION:
Brake fluid may damage painted surfaces
or plastic parts. Always clean up spilled
brake fluid immediately.
WARNING

Use only the designated quality brake
fluid: Other brake fluids may deteriorate
the rubber seals, causing leakage and
poor brake performance.

Refill with the same type of brake fluid:
Mixing brake fluids may result in a harm-
ful chemical reaction and lead to poor
brake performance.

Be careful that water does not enter the
brake master cylinder when refilling.
Water will significantly lower the boiling
point of the brake fluid and may result in
vapor lock.
Recommended brake fluid:
DOT 4
4.Air bleed:

Brake system
Refer to “BLEEDING THE HYDRAULIC
BRAKE SYSTEM” in CHAPTER 3.
5.Check:

Brake fluid level
Brake fluid level is below the “LOWER” level
line →
 Add the recomended brake fluid to the
proper level.
Refer to “CHECKING THE BRAKE FLUID
LEVEL” in CHAPTER 3. 
						

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CHASFRONT AND REAR BRAKES
INSTALLING THE REAR BRAKE MASTER 
CYLINDER
1.Install:

Copper washers 1

Brake hose 2
 

Union bolt 3
CAUTION:
When installing the brake hose onto the
brake master cylinder, make sure the brake
pipe touches the projection a as shown.
WARNING
Proper brake hose routing is essential to
insure safe machine operation. Refer to
“CABLE ROUTING”.
2.Fill:

Brake fluid reservoir
CAUTION:
Brake fluid may damage painted surfaces
or plastic parts. Always clean up spilled
brake fluid immediately.
WARNING

Use only the designated quality brake
fluid: Other brake fluids may deteriorate
the rubber seals, causing leakage and
poor brake performance.

Refill with the same type of brake fluid:
Mixing brake fluids may result in a harm-
ful chemical reaction and lead to poor
brake performance.

Be careful that water does not enter the
brake master cylinder when refilling.
Water will significantly lower the boiling
point of the brake fluid and may result in
vapor lock.
Recommended brake fluid:
DOT 4
New
T R..30 Nm (3.0 m  kg, 22 ft  lb) 
						

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CHAS
3.Air bleed:

Brake system
Refer to “BLEEDING THE HYDRAULIC
BRAKE SYSTEM” in CHAPTER 3.
4.Check:

Brake fluid level
Brake fluid level is below the “LOWER” level
line →
 Add the recommended brake fluid to
the proper level.
Refer to “CHECKING THE BRAKE FLUID
LEVEL” in CHAPTER 3.
FRONT AND REAR BRAKES 
						

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CHASFRONT AND REAR BRAKES
FRONT BRAKE CALIPERS
Order Job name/Part name Q’ty Remarks
Removing the front brake caliper
Remove the parts in the order below.
Brake fluid Drain.
Front wheel Refer to “FRONT WHEELS”.
1 Union bolt 1
Refer to “INSTALLING 
THE FRONT BRAKE CAL-
IPER”. 2 Copper washer 2
3 Brake hose 1 Disconnect.
4 Cap/retaining bolt 1/1 Loosen.
5 Brake pad holding bolt 2 Loosen.
6 Brake caliper mounting bolt 2
7 Brake caliper assembly 1
For installation, reverse the removal pro-
cedure.  
						

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CHASFRONT AND REAR BRAKES
Order Job name/Part name Q’ty Remarks
Disassembling the front brake cali-
perRemove the parts in the order below.
1
  Brake pad holding bolt 2
2
  Brake pad/pad shim 2/1
3
  Brake pad spring 1
4 Retaining bolt 1
5
 Caliper bracket 1
6
  Brake caliper piston 1
Refer to “DISASSEMBLING THE FRONT 
AND REAR BRAKE CALIPER/ASSEM-
BLING THE FRONT BRAKE CALIPER”. 7
 Dust seal 1
8
  Caliper piston seal 1
9
 Bleed screw 1
For assembly, reverse the disassembly 
procedure. 
						

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CHASFRONT AND REAR BRAKES
REAR BRAKE CALIPER
Order Job name/Part name Q’ty Remarks
Removing the rear brake caliper
Remove the parts in the order below.
Brake fluid Drain.
1 Parking brake cable 1 Disconnect.
2 Union bolt 1
Refer to “INSTALLING 
THE REAR BRAKE CALI-
PER”. 3 Copper washer 2
4 Brake hose 1 Disconnect.
5 Brake caliper mounting bolt 1
6 Brake caliper mounting bolt 1
7 Brake caliper assembly 1
For installation, reverse the removal pro-
cedure.  
						

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CHASFRONT AND REAR BRAKES
Order Job name/Part name Q’ty Remarks
Disassembling the rear brake caliper
Remove the parts in the order below.
1
 Adjusting bolt 1
2
 Locknut 1
3
  Parking brake lever 1
4  Parking brake case mounting bolt 2
5
  Parking brake case 1
6
 Gasket 1
7
 Spring 1
8
 Nut 1
9
Bearing 1
Refer to “ASSEMBLING THE REAR 
BRAKE CALIPER”. 0
Brake pad holding bolt 2
A
Lock washer 1 
						

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CHASFRONT AND REAR BRAKES
Order Job name/Part name Q’ty Remarks
B
  Brake pad/pad shim 2/1
C
  Brake pad spring 1
D
 Retaining bolt 1
E
 Caliper bracket 1
F
  Brake caliper piston 1
Refer to “DISASSEMBLING THE FRONT 
AND REAR BRAKE CALIPER/ASSEM-
BLING THE REAR BRAKE CALIPER”. G
 Dust seal 1
H
  Caliper piston seal 1
I
 O-ring 1
J
Bleed screw 1
For assembly, reverse the disassembly 
procedure. 
						

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CHASFRONT AND REAR BRAKES
DISASSEMBLING THE FRONT AND REAR 
BRAKE CALIPER
1.Remove:

Brake caliper piston

Dust seal 1
 

Caliper piston seal 2
 
***********************************************
Removal steps:

Blow compressed air into the hose joint
opening to force out the caliper piston from
the brake caliper body.
WARNING

Never try to pry out the caliper piston.

Cover the caliper piston with a rag. Be
careful not to get injured when the piston
is expelled from the master cylinder.

Remove the caliper piston seals.
***********************************************
EB702040
CHECKING THE FRONT AND REAR BRAKE 
CALIPER
WARNING
All internal brake components should be
cleaned in new brake fluid only. Do not use
solvents as they will cause seals to swell
and distort.Recommended brake component 
replacement schedule:
Brake pads As required
Piston seal, dust seal Every two years
Brake hoses Every two years
Brake fluidReplace when 
brakes are disas-
sembled. 
						

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CHASFRONT AND REAR BRAKES
1.Check:

Brake caliper piston 1
 
Scratches/rust/wear →
 Replace the brake
caliper assembly.

Brake caliper cylinder 2
 
Wear/scratches →
 Replace the brake caliper
assembly.

Brake caliper body 3
 
Cracks/damage →
 Replace.

Brake fluid delivery passage (brake caliper
body)
Blockage →
 Blow out with compressed air.
WARNING
Replace the caliper piston seal and dust
seal whenever the brake caliper is disas-
sembled.
ÈFront
ÉRear
È
É
ASSEMBLING THE FRONT BRAKE 
CALIPER
WARNING

All internal brake components should be
cleaned and lubricated with new brake
fluid only before installation.

Replace the caliper piston seal whenever
a brake caliper is disassembled.
1.Install:

Caliper piston seal 1

Dust seal 2
Recommended brake fluid:
DOT 4
New
New
2.Install:

Brake caliper piston 1