Poor Braking Performance; Faulty Front Fork Legs; Leaking Oil; Malfunction - Yamaha 2004 YP400 Service Manual

FAULTY FRONT FORK LEGS/UNSTABLE HANDLING
EAS00857

POOR BRAKING PERFORMANCE

• Worn brake pad
• Worn brake disc
• Air in hydraulic brake system
• Leaking brake fluid
• Faulty brake caliper kit
• Faulty brake caliper seal
• Loose union bolt
• Damaged brake hose
• Oil or grease on the brake disc
• Oil or grease on the brake pad
• Incorrect brake fluid level
EAS00861

FAULTY FRONT FORK LEGS

LEAKING OIL

• Bent, damaged or rusty inner tube
• Cracked or damaged outer tube
• Improperly installed oil seal
• Damaged oil seal lip
• Incorrect oil level (high)
• Loose damper rod assembly bolt
• Damaged damper rod assembly bolt copper
washer
• Cracked or damaged cap bolt O-ring
EAS00862

UNSTABLE HANDLING

Handlebar
• Bent or improperly installed handlebar
Steering head components
• Improperly installed lower handlebar holder
• Improperly installed lower bracket
(improperly tightened steering ring nut)
• Bent steering stem
• Damaged ball bearing or bearing race
Front fork leg(s)
• Uneven oil levels (both front fork legs)
• Unevenly tensioned fork spring (both front
fork legs)
• Broken fork spring
• Bent or damaged inner tube
• Bent or damaged outer tube
POOR BRAKING PERFORMANCE/
9 - 5

MALFUNCTION

• Bent or damaged inner tube
• Bent or damaged outer tube
• Damaged fork spring
• Worn or damaged outer tube bushing
• Bent or damaged damper rod
• Incorrect oil viscosity
• Incorrect oil level
Rear shock absorber assembly(-ies)
• Faulty rear shock absorber spring
• Leaking oil
Tire(s)
• Uneven tire pressures (front and rear)
• Incorrect tire pressure
• Uneven tire wear
Wheel(s)
• Incorrect wheel balance
• Deformed cast wheel
• Damaged wheel bearing
• Bent or loose wheel axle
• Excessive wheel runout
Frame
• Bent frame
• Damaged steering head pipe
• Improperly installed bearing race
TRBL
SHTG