2005 YAMAHA YZ85 oil

5 - 25
CHAS
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 poor brake per-
formance.

Refill with the same type of brake fluid;
mixing fluids may result in a harmful
chemical reaction and lead to poor perfor-
mance.

Be careful that water does not enter the
master cylinder when refilling. Water will
significantly lower the boiling point of the
fluid and may result in vapor lock.
CAUTION:
Brake fluid may erode painted surfaces or
plastic parts. Always clean up spilled fluid
immediately.
ÈFront
ÉRear
2. Air bleed:

Brake system
Refer to “BRAKE SYSTEM AIR BLEED-
ING” section in the CHAPTER 3.
Recommended brake fluid:
DOT #4
È
5PA50770
É
5PA50780
3. Inspect:

Brake fluid level
Fluid at lower level → Fill up.
Refer to “BRAKE FLUID LEVEL INSPEC-
TION” section in the CHAPTER 3.
FRONT BRAKE AND REAR BRAKE

5 - 28
CHAS
EC558000
FRONT FORK DISASSEMBLY
5PA50830
Extent of removal:
1 Oil seal removal
2 Damper rod removal
Extent of removal Order Part name Q’ty Remarks
FRONT FORK DISASSEMBLY
1 Front fork cap bolt 1 Use special tool.
Refer to “REMOVAL POINTS”.
2 Fork spring 1 Drain the fork oil.
3 Dust seal 1
Refer to “REMOVAL POINTS”.
4 Stopper ring 1
5 Inner tube 1
6 Outer tube 1
7 Piston metal 1
8 Slide metal 1
9 Oil seal washer 1
0 Oil seal 1
A Spring guide 1
B Base valve 1 Use special tool.
C Damper rod 1 Refer to “REMOVAL POINTS”.
1
2
FRONT FORK

5 - 29
CHAS
EC556000
HANDLING NOTE
NOTE:
The front fork requires careful attention. So it is
recommended that the front fork be maintained
at the dealers.
CAUTION:
To prevent an accidental explosion of air,
the following instructions should be
observed:

The front fork with a built-in piston rod
has a very sophisticated internal con-
struction and is particularly sensitive to
foreign material.
Use enough care not to allow any foreign
material to come in when the oil is
replaced or when the front fork is disas-
sembled and reassembled.

Before removing the cap bolts or front
forks, be sure to extract the air from the
air chamber completely.
EC553000
REMOVAL POINTS
Front fork cap bolt
1. Remove:

Front fork cap bolt 1
From the outer tube.
NOTE:
Before removing the front fork from the
machine, loosen the front fork cap bolt.
2. Remove:

Front fork cap bolt 1
NOTE:

Set the rod holder 2 between the locknut 3
and washer 4.

Hold the locknut and remove the front fork
cap bolt.
Rod holder:
YM-01434/90890-01434
5PA50840
5PA50850
FRONT FORK

5 - 30
CHAS
EC553201
Inner tube
1. Remove:

Dust seal 1

Stopper ring 2
Using slotted-head screwdriver.
CAUTION:
Take care not to scratch the inner tube.
5PA50860
2. Remove:

Inner tube 1
Oil seal removal steps:

Push in slowly a the inner tube just before
it bottoms out and then pull it back quickly
b.

Repeat this step until the inner tube can
be pulled out from the outer tube.
5PA50870
EC553311
Damper rod
1. Remove:

Base valve 1

Damper rod 2
NOTE:
Use a damper rod holder 3 to lock the damper
rod.
EC554000
INSPECTION
EC554100
Damper rod
1. Inspect:

Damper rod 1
Bend/damage → Replace damper rod.
CAUTION:
The front fork with a built-in piston rod has
a very sophisticated internal construction
and is particularly sensitive to foreign
material.
Use enough care not to allow any foreign
material to come in when the oil is replaced
or when the front fork is disassembled and
reassembled.
Damper rod holder:
YM-01454/90890-01454
5PA50880
5PA50890
FRONT FORK

5 - 31
CHAS
EC554200
Base valve
1. Inspect:

Valve assembly 1
Wear/damage → Replace.

O-ring 2
Damage → Replace.
5PA50900
EC554400
Fork spring
1. Measure:

Fork spring free length a
Out of specification → Replace.
EC554502
Inner tube
1. Inspect:

Inner tube surface a
Score marks → Repair or replace.
Use #1,000 grit wet sandpaper.
Damaged oil lock piece → Replace.

Inner tube bends
Out of specification → Replace.
Use the dial gauge 1.
NOTE:
The bending value is shown by one half of the
dial gauge reading.
WARNING
Do not attempt to straighten a bent inner
tube as this may dangerously weaken the
tube.
EC554600
Outer tube
1. Inspect:

Outer tube 1
Score marks/wear/damage → Replace.
Fork spring free length:
430 mm (16.9 in)
: 425 mm (16.7 in)
Inner tube bending limit:
0.2 mm (0.008 in)
5PA50910
5PA50920
5PA50930
FRONT FORK

5 - 33
CHAS
5. Install:

Spring guide 1

Locknut 2
To damper rod 3.
NOTE:
Install the spring guide with its cut a facing
downward.
5PA50980
6. Install:

Dust seal 1

Stopper ring 2

Oil seal 3

Oil seal washer 4

Slide metal 5
To inner tube 6.
NOTE:

Apply the fork oil on the inner tube.

When installing the oil seal, use vinyl seat a
with fork oil applied to protect the oil seal lip.

Install the oil seal with its manufacture’s
marks or number facing the axle holder side.
5PA50990
5PA51000
7. Install:

Piston metal 1
NOTE:
Install the piston metal onto the slot on inner
tube.
5PA51010
8. Install:

Outer tube 1
To inner tube 2.
5PA51020
FRONT FORK

5 - 34
CHAS
9. Install:

Slide metal 1

Oil seal washer 2
To outer tube slot.
NOTE:
Press the slide metal into the outer tube with
fork seal driver 3.
Fork seal driver:
YM-01442/90890-014425PA51030
5PA51040
10. Install:

Oil seal 1
NOTE:
Press the oil seal into the outer tube with fork
seal driver 2.
Fork seal driver:
YM-01442/90890-01442
5PA51050
11. Install:

Stopper ring 1
NOTE:
Fit the stopper ring correctly in the groove in
the outer tube.
5PA51060
12. Install:

Dust seal 1
NOTE:
Apply the lithium soap base grease on the
inner tube.
5PA51070
FRONT FORK

5 - 35
CHAS
13. Check:

Inner tube smooth movement
Tightness/binding/rough spots → Repeat
the steps 2 to 12.
5PA51080
14. Compress the front fork fully.
15. Fill:

Front fork oil
Until outer tube top surface with recom-
mended fork oil 1.
CAUTION:

Be sure to use recommended fork oil. If
other oils are used, they may have an
excessively adverse effect on the front
fork performance.

Never allow foreign materials to enter the
front fork.
Recommended oil:
Suspension oil “01”
5PA51090
16. After filling, pump the damper rod 1 slowly
up and down more than 10 times to distrib-
ute the fork oil.
17. Fill:

Front fork oil
Until outer tube top surface with recom-
mended fork oil once more.
5PA51100
18. After filling, pump the outer tube 1 slowly
up and down (about 150 mm (5.9 in)
stroke) to distribute the fork oil once more.
NOTE:
Be careful not to excessive full stroke. A stroke
of 150 mm (5.9 in) or more will cause air to
enter. In this case, repeat the steps 15 to 18.
5PA51110
FRONT FORK