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14

CHECKING THE REAR BRAKE FLUID LEVEL / CHECKING THE

REAR BRAKE PADS/BLEEDING THE HYDRAULIC BRAKE SYSTEM

INSP

ADJ

CAUTION:

NOTE:

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

Refill with the same type of brake fluid that
is already in the system. Mixing brake
fluids may result in a harmful chemical
reaction, leading to poor brake perfor-
mance.

When refilling, be careful that water does
not enter the reservoir. Water will signifi-
cantly lower the boiling point of the brake
fluid and could cause vapor lock.

Brake fluid may damage painted surfaces
and plastic parts. Therefore, always clean
up any split brake fluid immediately.

In order to ensure a correct reading of the brake
fluid level, make sure that the top of the reser-
voir is horizontal.

EB304030

CHECKING THE REAR BRAKE PADS
The following procedure applies to all of the
brake pads.

1. Operate the brake.
2. Check:

brake pad
Wear indicators 

1

 almost touch the brake

disc 

 Replace the brake pads as a set.

Refer to “FRONT BRAKE” in chapter 7.

A Front brake

EB304070

BLEEDING THE HYDRAULIC BRAKE
SYSTEM

Bleed the hydraulic brake system whenever:

the system was disassembled,

a brake hose was loosened or removed,

the brake fluid level is very low,

brake operation is faulty.

Summary of Contents for YP250D 98

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Page 3: ...cessary to use this Supplementary Service Manual together with the following manual YP250 SERVICE MANUAL 4UC AE1 YP250 J SUPPLEMENTARY SERVICE MANUAL 4UC AE2 YP250D 98 SUPPLEMENTARY SERVICE MANUAL 1997 by Yamaha Motor Co Ltd First Edition December 1997 Any reproduction or unauthorized use without the written permission of Yamaha Motor Co Ltd is expressly prohibited ...

Page 4: ...l its models Modifications and signifi cant changes in specifications or procedures will be forwarded to all authorized Yamaha dealers and will appear in future editions of this manual where applicable Designs and specifications are subject to change without notice IMPORTANT INFORMATION Particularly important information is distinguished in this manual by the following notations The Safety Alert S...

Page 5: ... To heps identify parts and clarify procedure steps there are exploded diagrams at start of each remov al and disassembly section 1 An easy to see exploded diagram 4 is provided for disassembly and assembly jobs 2 Numbers 5 are given in the order of jobs in the exploded diagram A number that is enclosed by a circle indicates a disassembly step 3 An explanation of jobs and notes is presented in an ...

Page 6: ...he text 10 Possible to maintain with engine mounted 11 Filling fluid 12 Lubricant 13 Special tool 14 Tightening 15 Wear limit clearance 16 Engine speed 17 Ω V A Illustrated symbols 18 to 23 in the exploded dia grams indicate the types of lubricants and lu brication points 18 Apply engine oil 19 Apply gear oil 20 Apply molybdenum disulfide oil 21 Apply wheel bearing grease 22 Apply lightweight lith...

Page 7: ...EAT 12 ADJUSTING THE REAR BRAKE 13 CHECKING THE REAR BRAKE FLUID 13 CHECKING THE REAR BRAKE PADS 14 BLEEDING THE HYDRAULIC BRAKE SYSTEM 14 ADJUSTING THE REAR SHOCK ABSORBER ASSEMBLIES 16 CHASSIS 17 REAR WHEEL AND BRAKE DISC 17 CHECKING THE BRAKE DISC 18 REAR BRAKE 19 BRAKE PAD 19 REPLACING THE BRAKE PADS 20 CALIPER 21 CALIPER DISASSEMBLY 22 INSTALLING THE REAR BRAKE CALIPER 23 MASTER CYLINDER 24 M...

Page 8: ......

Page 9: ...ximum load except motorcycle Loading condition A front rear Loading condition B front rear High speed riding front rear 191 kg 0 90 kg 175 kPa 1 75 kg cm2 1 75 bar 200 kPa 2 0 kg cm2 2 0 bar 90 191 kg 200 kPa 2 0 kg cm2 2 0 bar 225 kPa 2 25 kg cm2 2 25 bar 200 kPa 2 0 kg cm2 2 0 bar 250 kPa 2 5 kg cm2 2 5 bar Brake Front brake type operation Rear brake type operation Single disc brake Right hand o...

Page 10: ...lot air jet P A J 1 Needle jet N J Pilot outlet P O Pilot jet P J Bypass B P Pilot screw P S Valve seat size V S Starter jet 1 G S 1 Starter jet 2 G S 2 Float height F H Engine idle speed Intake vacuum Oil temperature Cooling water temperature Y28V 1A 4UC 02 4UD 00 CH ø28 130 ø0 9 5D32 3 5 11 ø1 2 85 ø0 8 44 0 7 3 1 7 8 1 5 8 CH 1 4 ø0 45 ø0 47 CH ø0 5 27 mm 1 350 1 450 r min 220 260 mmHg 65 75 C ...

Page 11: ...ness Pad thickness Master cylinder inside diameter Caliper cylinder outside diameter Brake fluid type Single 230 x 5 3 mm 5 3 mm 11 mm 22 2 22 2 mm DOT 4 0 8 mm ELECTRICAL Item Standard limit T C I Pickup coil resistance color T C I unit model manufacturer 189 231 Ω at 20_C Yellow Green J4T091 MITSUBISHI ...

Page 12: ...s A Pass the rear brake hose through the handlebar holder B Use a plastic band to fasten the rear brake cable to the steering head pipe C Use a plastic band to fasten the throttle cable and wireharness to the frame D Pass the rear brake hose through the frame guide then use a plastic band to fasten them to frame E Pass the carburetor air ventilation hose coolant drain hose and carburetor fuel drai...

Page 13: ...eft 90 90 H Pass the fuel tank over flow hose through inside of the frame clamp I Use a plastic band to fasten the throttle cable to frame J Use a plastic band to fasten the wireharness to the headlight stay K Locate the band end as illustration CABLE ROUTING SPEC ...

Page 14: ...rotector end F Use a plastic band to fasten the wireharness and seat lock cable 13 Reservoir tank 14 Fuel tank breather hose 15 Air filter 16 Mud guard 17 Down tube 18 Wireharness 19 Engine bracket 20 Engine ground lead 21 AC magnet lead 22 Starter motor lead 23 Rear brake hose 1 Box light 2 Rectifire regulator 3 Fuel sender 4 Roll over valve 5 Fuse 6 Battery negative lead 7 Seat lock cable 8 Hand...

Page 15: ...fasten it H Pass the reservoir tank over flow hose through the clamp inside of the frame I Pass the rear brake hose wireharness battery leads through the guide J Use a steel band to fasten the wireharness battery leads K Locate the band end as illustration CABLE ROUTING SPEC ...

Page 16: ...arting circuit cut off relay 8 Auto choke lead 9 AC magneto lead 10 Starter motor lead 11 Engine ground lead 12 Seat lock cable A Use a steel clamp on the frame to fasten the sidestand lead B Pass the thermo switch lead through outside of frame C Use a clamp on the frame to fasten the sidestand switch lead and battery positive lead D Use a steel clamp on behind of the frame to fasten the wireharne...

Page 17: ...ble 6 Front brake hose 7 Headlight stay 8 Grip warmer lead 9 Handlebar switch lead right 10 Front brake switch lead 11 Seat lock cable 12 Handlebar switch lead left A Pass the speedometer cable and front brake hose through the holder B Use a steel clamp on headlight stay to fasten the headlight lead and horn lead C Do not interfere each other after installing the handleber upper cover ...

Page 18: ...ion fluid level and vehicle for fluid leakage See NOTE Correct accordingly Replace brake pads if necessary 8 Wheels Check balance runout and for damage Rebalance or replace if necessary 9 Tires Check tread depth and for damage Replace if necessary Check air pressure Correct if necessary 10 Wheel bearings Check bearing for looseness damage Replace if necessary 11 Steering bearings Check bearing pla...

Page 19: ... Since these items require special tools data and technical skills they should be serviced by a Yamaha dealer EAU00477 SThe air filter needs more frequent service if you are riding in unusually wet or dusty areas SBrake fluid replacement 1 When disassembling the master cylinder or caliper cylinder always replace the brake fluid Check the brake fluid level regularly and fill as required 2 Replace t...

Page 20: ...al procedure for installation Order Job name Part name Q ty Remarks 1 2 3 4 5 6 7 8 Side panel and seat removal Rear panel Side panel left Side panel right Rivet Front panel Clip Damper assembly Seat 1 1 1 2 1 2 1 1 Remove the parts in order NOTE COVER AND PANEL INSP ADJ COVER AND PANEL SIDE PANEL AND SEAT ...

Page 21: ...irection Brake lever free play is increased Direction Brake lever free play is decreased c Tighten the locknut 1 to specification After adjusting the brake lever free play make sure that there is no brake drag 3 Adjust rear brake light switch Refer to ADJUSTING THE REAR BRAKE LIGHT SWITCH EB304021 CHECKING THE REAR BRAKE FLUID LEVEL 1 Stand the scooter on a level surface Place the scooter on a sui...

Page 22: ...of the brake fluid and could cause vapor lock Brake fluid may damage painted surfaces and plastic parts Therefore always clean up any split brake fluid immediately In order to ensure a correct reading of the brake fluid level make sure that the top of the reser voir is horizontal EB304030 CHECKING THE REAR BRAKE PADS The following procedure applies to all of the brake pads 1 Operate the brake 2 Ch...

Page 23: ...e disappeared 2 Bleed hydraulic brake system a Add the recommended brake fluid to the proper level b Install the brake master cylinder reservoir diaphragm c Connect a clear plastic hose 1 tightly to the bleed screw 2 d Place the other end of the hose into a con tainer e Slowly squeeze the brake lever several times f Fully squeeze the brake lever without re leasing it g Loosen the bleed screw This ...

Page 24: ...danger of it falling over Always adjust both rear shock absorber as semblies evenly Uneven adjustment can re sult in poor handling and loss of stability Spring preload Never go beyond the maximum or minimum adjustment positions 1 Adjust spring preload a Insert a screwdriver into the hole 1 in the spring seat b Turn the spring seat 1 in direction a or b Direction Spring preload is increased suspens...

Page 25: ... Rear wheel and brake disc removal Swingarm Rear wheel Brake disc 1 1 Refer to REAR SHOCK ABSORBER AND SWINGARM section Reverse the removal procedure for installation 23 Nm 2 3 m kg REAR WHEEL AND BRAKE DISC CHAS CHASSIS REAR WHEEL AND BRAKE DISC ...

Page 26: ... brake disc deflection Out of specification Correct the brake disc deflection or replace the brake disc Brake disc deflection limit maximum 4 8 mm 3 Measure brake disc thickness Measure the brake disc thickness at a few different locations Out of specification Replace Brake disc thickness limit minimum 0 2 mm ...

Page 27: ...rake pad removal Caliper support bolt Caliper assembly Brake pad Pad support 1 1 2 2 Remove the parts in order Refer to REPLACING THE BRAKE PADS section Reverse the removal procedure for installation 23 Nm 2 3 m kg REAR BRAKE CHAS REAR BRAKE BRAKE PAD ...

Page 28: ...if either is found to be worn to the wear limit 3 Push the caliper piston into the brake cali per by finger When pushing the caliper piston into the brake caliper brake fluid level in reservoir tank is increasing higher 4 Install Brake pad 1 5 Install Caliper assembly Caliper support bolt 23 Nm 2 3 mSkg 6 Check Brake fluid level Refer to CHECKING THE REAR BRAKE FLUID LEVEL section 7 Check Brake le...

Page 29: ... Plain washer Brake hose Caliper support bolt Caliper assembly 1 1 2 1 2 1 Remove the parts in order Refer to BRAKE FLUID REPLACEMENT section in CHAPTER 3 Refer to INSTALLING THE REAR BRAKE CALIPER section Reverse the removal procedure for installation 26 Nm 2 6 m kg 7 Nm 0 7 m kg 23 Nm 2 3 m kg REAR BRAKE CHAS CALIPER ...

Page 30: ... support Caliper piston Dust seal Piston seal Bleed screw Cap 2 2 2 2 2 1 1 Remove the parts in order Refer to BRAKE CALIPER DISASSEMBLY ASSEMBLY section in Chapter 7 Reverse the disassembly procedure for assembly 1 2 3 4 5 6 6 Nm 0 6 m kg REAR BRAKE CHAS CALIPER DISASSEMBLY ...

Page 31: ... 6 m kg CAUTION INSTALLING THE REAR BRAKE CALIPER 1 Install Caliper 1 Caliper support bolt 2 Brake hose 3 Plain washer 4 Union bolt 5 When installing the brake hose to the caliper lightly touch the brake hose with the stopper a on the caliper ...

Page 32: ... switch Union bolt Plain washer Brake hose Master cylinder bracket Master cylinder 1 1 1 1 1 2 1 1 1 Remove the parts in order Refer to BRAKE FLUID REPLACEMENT section in CHAPTER 3 Refer to MASTER CYLINDER INSTALLATION section in Chapter 7 Reverse the removal procedure for installation 10 Nm 1 0 m kg 10 Nm 1 0 m kg 26 Nm 2 6 m kg REAR BRAKE CHAS MASTER CYLINDER ...

Page 33: ...isassembly Master cylinder boot Circlip Master cylinder assembly Spring 1 1 1 1 Remove the parts in order Refer to MASTER CYLINDER ASSEMBLY section in Chapter 7 Reverse the disassembly procedure for assembly 1 2 3 4 REAR BRAKE CHAS MASTER CYLINDER DISASSEMBLY ...

Page 34: ... Swingarm Collar Oil seal Bearing 1 2 1 1 1 1 1 1 1 1 Remove the parts in order Refer to COVER AND PANEL section Loosen Remove with the rear brake applied Reverse the removal procedure for installation NOTE 40 Nm 4 0 m kg NOTE 7 Nm 0 7 m kg 16 Nm 1 6 m kg 130 Nm 13 0 m kg 20 Nm 2 0 m kg 49 Nm 4 9 m kg 53 Nm 5 3 m kg REAR SHOCK ABSORBER AND SWINGARM CHAS REAR SHOCK ABSORBER AND SWINGARM ...

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