brake YAMAHA YFM660R 2003 Owner's Guide

7-77

If your ATV encounters shallow water:
Ride slowly and carefully through slow moving
water, watching for obstacles. Be sure to let
water drain from the ATV and CHECK YOUR
BRAKES FOR PROPER OPERATION when
you come out of the water. Do not continue to
ride your ATV until you have regained ade-
quate braking ability. (See pages 7-63–7-65.)
U5LP62.book Page 77 Wednesday, May 8, 2002 11:24 AM

8-7
EBU00262
PERIODIC MAINTENANCE/LUBRICATION
ITEM ROUTINEINITIAL EVERY
1
month3
months6
months6
months1
year
Valves*•Check valve clearance.
•Adjust if necessary.
Cooling system•Check coolant leakage.
•Repair if necessary.
•Replace coolant every 24 months.Spark plug•Check condition.
•Adjust gap and clean.
•Replace if necessary.Air filter element•Clean.
•Replace if necessary.Every 20–40 hours
(More often in wet or dusty areas.)
Carburetor*•Check starter (choke) operation.
•Adjust engine idling speed.Crankcase breather
system*•Check breather hose for cracks or damage.
•Replace if necessary.Exhaust system*•Check for leakage.
•Tighten if necessary.
•Replace gasket if necessary.Fuel line*•Check fuel hose for cracks or damage.
•Replace if necessary.Engine oil
•Replace (Warm engine before draining.)Engine oil filter cartridge
•Replace if necessary.Drive chain
•Check and adjust slack/alignment/clean/lube.Front brake*•Check free play/operation/fluid leakage/
See NOTE Page 8-8.
•Correct if necessary.Rear brake*•Check operation/fluid leakage/See NOTE Page 8-8.
•Correct if necessary.Clutch*•Check operation.
•Adjust if necessary.U5LP62.book Page 7 Wednesday, May 8, 2002 11:24 AM

8-8 * It is recommended that these items be serviced by a Yamaha dealer.
** Lithium-soap-based grease
NOTE:

Recommended brake fluid: DOT4


Brake fluid replacement:
•When disassembling the master cylinders or calipers, replace the brake fluid. Normally check the
brake fluid level and add fluid as required.
•On the inner parts of the master cylinders and calipers, replace the oil seals every two years.
•Replace the brake hoses every four years, or if cracked or damaged.
Wheels*•Check balance/damage/runout.
•Replace if necessary.Wheel bearings*•Check bearing assemblies for looseness/damage.
•Replace if damaged.Steering system*•Check operation.
•Repair if damaged.
•Check toe-in.
•Adjust if necessary.Front and rear
suspension*•Check operation.
•Correct if necessary.Upper and lower arm
pivot and steering shaft*•Lubricate every 6 months.**Rear arm pivot*
•Lubricate every 6 months.**Fittings and fasteners*•Check all chassis fittings and fasteners.
•Correct if necessary.Lights and switches*•Check operation.
•Adjust headlight beam.
ITEM ROUTINEINITIAL EVERY
1
month3
months6
months6
months1
year
U5LP62.book Page 8 Wednesday, May 8, 2002 11:24 AM

8-61 1. Wear indicator groove
1. Rainure d’indicateur d’usure
1. Ranura indicador de desgaste
Front
Avant
Delantero1. Wear indicator groove
1. Rainure d’indicateur d’usure
1. Ranura indicador de desgasteRear
Arrière
Trasero
EBU01027
Front and rear brake pad inspection
Each brake pad is provided with a wear indicator
groove. The indicators allow checking of brake
pad wear without disassembling the brake. Apply
the brake and inspect the wear indicator grooves.
If the pad is worn to the point that the wear indica-
tor grooves are almost in contact with the disc
plate, ask a Yamaha dealer to replace the pads.
U5LP62.book Page 61 Wednesday, May 8, 2002 11:24 AM

8-63 1. Minimum level mark
1. Repère de niveau minimum
1. Marca de nivel mínimo
Front
Avant
Delantero1. Minimum level mark
1. Repère de niveau minimum
1. Marca de nivel mínimo Rear
Arrière
Trasero
EBU01214
Brake fluid level inspection
Insufficient brake fluid may let air enter the brake
system, possibly causing the brakes to become in-
effective.
Before riding, check that the brake fluid is above
the minimum level mark and replenish if neces-
sary. A low brake fluid level may indicate worn
brake pads and/or brake system leakage. If the
brake fluid level is low, be sure to check the brake
pads for wear and the brake system for leakage.
U5LP62.book Page 63 Wednesday, May 8, 2002 11:24 AM

8-65 1. Brake fluid reservoir cover
2. Bolt (× 2)
1. Cache du réservoir de liquide de frein
2. Boulon (× 2)
1. Cubierta del depósito de líquido de frenos
2. Perno (× 2)
Rear
Arrière
Trasero
NOTE:_ To access the rear brake fluid reservoir, remove
the reservoir cover by removing the bolts. _Observe these precautions:

When checking the brake fluid level, make sure
the top of the brake fluid reservoir is level.


Use only the designated quality brake fluid, oth-
erwise, the rubber seals may deteriorate, caus-
ing leakage and poor brake performance.


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


Be careful that water does not enter the brake
fluid reservoir when refilling. Water will signifi-
cantly lower the boiling point of the fluid and
may result in vapor lock. Recommended brake fluid: DOT 4
U5LP62.book Page 65 Wednesday, May 8, 2002 11:24 AM

8-67

Brake fluid may deteriorate painted surfaces or
plastic parts. Always clean up spilled fluid im-
mediately.


Have a Yamaha dealer check the cause if the
brake fluid level goes down.
EBU01186
Brake fluid replacement
Complete fluid replacement should be done only
by trained Yamaha service personnel. Have a
Yamaha dealer replace the following components
during periodic maintenance or when they are
damaged or leaking.

Replace the oil seals every two years.


Replace the brake hoses every four years.
U5LP62.book Page 67 Wednesday, May 8, 2002 11:24 AM

8-69 a. Brake lever free play
a. Jeu du levier de frein
a. Juego de la palanca de freno
EBU01188
Front brake lever free play
The front brake lever should have a free play of
zero mm at the lever end. If not, have a Yamaha
dealer check the brake system.
WARNING
_ Operating with improperly serviced or adjust-
ed brakes could cause loss of braking ability
which could lead to an accident.
After servicing:

Make sure the brakes operate smoothly
and that the free play is correct.


Make sure the brakes do not drag.


Make sure the brakes are not spongy. All
air must be bled from the brake system.
Replacement of brake components requires
professional knowledge. These procedures
should be performed by a Yamaha dealer.
_
U5LP62.book Page 69 Wednesday, May 8, 2002 11:24 AM

8-71 a. Brake pedal position
a. Position de la pédale de frein
a. Posición del pedal del freno
EBU01079
Brake pedal height adjustment
The top of the brake pedal should be positioned
4 mm below the top of the footrest. If not, have a
Yamaha dealer adjust it.
WARNING
_ Operating with improperly serviced or adjust-
ed brakes could cause loss of braking ability,
which could lead to an accident. After servic-
ing:

Make sure the brakes operate smoothly
and that the brake pedal position is cor-
rect.


Make sure the brakes do not drag.


Make sure the brakes are not spongy. All
air must be bled from the brake system.
Replacement of brake components requires
professional knowledge. These procedures
should be performed by a Yamaha dealer.
_
U5LP62.book Page 71 Wednesday, May 8, 2002 11:24 AM

8-73 1. Locknut 2. Adjusting bolt
A. Cable length
1. Contre-écrou 2. Boulon de réglage
A. Longueur de câble
1. Contratuerca 2. Perno de ajuste
A. Longitud del cable
1. Locknut 2. Adjusting bolt
1. Contre-écrou 2. Boulon de réglage
1. Contratuerca 2. Perno de ajuste
EBU01192
Parking brake adjustment
Parking brake adjustment may be required if the
parking brake does not hold properly. The cable
length
A should be adjusted to 64–68 mm.
1. Fully loosen the locknut and the adjusting bolt
at the clutch lever.
2. Loosen the locknut and the adjusting bolt at
the rear brake caliper.
3. Turn the adjusting bolt at the clutch lever in
direction
a to increase the cable length or in
direction
b to decrease the cable length.NOTE:_ If the cable cannot be adjusted to specification,
consult a Yamaha dealer. _4. Tighten the locknut at the clutch lever.
U5LP62.book Page 73 Wednesday, May 8, 2002 11:24 AM