Shimano deore XT Technical Service Instruction

General Safety Information

Technical Service Instructions SI-8A30C

Disc Brake System

(For Cross-Country)

WARNING

• Please use extra caution to keep your fingers away from the rotating
disc brake rotor during installing or servicing the wheel. The rotor is
sharp enough to inflict severe injury to your fingers if caught within the
openings of moving rotor.

• The calipers and rotor will become hot when the brakes are operated, so do not touch
them while riding or immediately after dismounting from the bicycle, otherwise you may
get burned. Check that the brake components have cooled down sufficiently before
attempting to adjust the brakes.

• The required braking distance will be longer during wet weather.
Reduce your speed and apply the brakes early and gently.

• If the road surface is wet, the tires will skid more easily. If the tires skid, you may fall off
the bicycle. To avoid this, reduce your speed and apply the brakes early and gently.

• Always make sure that the front and rear brakes are working correctly before you ride
the bicycle.

• Be careful not to allow any oil or grease to get onto the rotor and brake pads, otherwise
the brakes may not work correctly.

• If any oil or grease do get on the pads, you should replace the pads.
If any oil or grease gets on the rotor, you should clean the rotor. If
this is not done, the brakes may not work correctly.

• Before riding the bicycle, check that the pad thicknesses are 0.5 mm
or more.

• Vapor lock may occur if the brakes are applied continuously. To
relieve this condition, momentarily release the lever.

• Use only genuine Shimano mineral oil. If other types of oil are used, it may cause
problems with brake operation, and cause the system to be unuseable.

• Be sure to use only oil from a freshly-opened container, and do not re-use oil which has
been drained from the bleed nipple. Old oil or already-used oil may contain water which
could cause vapor lock in the brake system.

• Be careful not to let water or air bubbles to get into the brake system, otherwise vapor
lock may occur. Be particularly careful when removing the cover of the reservoir tank.

• When turning the bicycle upside down or on its side the brake system may have some
air bubbles inside the reservoir tank which are still there when the reservoir tank cover is
replaced, or which accumulate in various parts of the brake system when it is used for
long periods. The M765 disc brake system is not designed to be turned upside down. If
the bicycle is turned upside down or on its side, the air bubbles inside the reservoir tank
may move in the direction of the calipers. If the bicycle is ridden in this condition, there is
the danger that the brakes may not operate and a serious accident could occur.
If the bicycle has been turned upside down or on its side, be sure to operate the brake
lever a few times to check that the brakes operate normally before riding the bicycle. If
the brakes do not operate normally, adjust them by the following procedure.

• If fluid leaks occur, immediately stop using the brakes and carry out the appropriate
repairs. If you continue riding the bicycle while fluid is leaking, there is the danger that
the brakes may suddenly stop working.

• Check that the quick release lever is on the right side (the opposite side to the rotor). If
the quick release lever is on the same side as the rotor, there is the danger that it may
interfere with the rotor, so check that it does not interfere.

• It is important to completely understand the operation of your bicycle's brake system.
Improper use of your bicycle's brake system may result in a loss of control or an
accident, which could lead to severe injury. Because each bicycle may handle differently,
be sure to learn the proper braking technique (including brake lever pressure and bicycle
control characteristics) and operation of your bicycle. This can be done by consulting
your professional bicycle dealer and the bicycle's owners manual, and by practicing your
riding and braking technique.

• The M765 disc brakes are designed for optimum performance when used in combination

Vapor lock is a phenomenon in which the oil inside the brake system becomes
heated, which causes any water or air bubbles inside the brake system to expand.
This can then result in a sudden increase in the brake lever stroke.

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If brake operation is sluggish when the lever is depressed

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Set the brake lever so that it is parallel to the ground, and then gently depress the
brake lever several times and wait for the bubbles to return to the reservoir tank. It is
recommended that you then remove the reservoir tank cover and fill the reservoir
tank with mineral oil until no bubbles remain.
If the brakes still operate sluggishly, bleed the air from the brake system.
(Refer to "Adding the mineral oil and bleeding air".)

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CAUTION

• M07-S brake pads are designed to reduce the amount of noise which is
generated between the pads and the rotor when the brakes are operated.
A longer running-in period is required for this type of pad compared to
M06 pads.

■ Handling the mineral oil

• Use safety glasses when handling, and avoid contact with eyes. Contact with eyes may
result in irritation.
In the event of eye contact, flush with fresh water and seek medical assistance
immediately.

• Use gloves when handling. Contact with skin may cause a rash and discomfort.
In the event of skin contact, wash well with soap and water.

• Inhalation of oil mist or vapors may cause nausea. Cover nose and mouth with a
respirator type mask and use in a well ventilated area.
If mist or vapor is inhaled, go immediately to an area with fresh air. Cover up with a
blanket. Stay warm and stable and seek professional medical advice.

• Do not drink. May cause vomiting or diarrhea.

• Keep out of reach of children.

• Do not cut, heat, weld or pressurize the oil container, as this may cause explosion or fire.

• Disposal of Used Oil : Follow local county and/or state codes for disposal. Use care

when preparing oil for disposal.

• Directions : Keep the container sealed to prevent foreign objects and moisture from

getting inside, and store it in a cool, dark area away from direct sunlight or
heat.

■ Burn-in period

• Disc brakes have a burn-in period, and the braking force will gradually increase as the
burn-in period progresses. Make sure that you are aware of any such increases in
braking force when using the brakes during the burn-in period. The same thing will
happen when the brake pads or rotor are replaced.

■ When cleaning with a compressor

• If disassembling the caliper body to clean the internal parts using a compressor, note
that moisture from the compressed air may remain on the caliper components. Let the
caliper components dry sufficiently before reassembling the calipers.

Note

• When the bicycle wheel has been removed, it is recommended that pad spacers should
be installed. The pad spacers will prevent the piston from coming out if the brake lever is
depressed while the wheel is removed.

• If the brake lever is depressed without the pad spacers installed, the pistons will protrude
further than is normal. Use a flat-tipped screwdriver or similar tool to push back the brake
pads, while being careful not to damage the surfaces of the brake pads. (If the brake
pads are not installed, push the pistons straight back in, while being careful not to
damage them.)
If it is difficult to push the brake pads or pistons back, remove the reservoir tank cover
and then try again. (Note that some oil may overflow from the reservoir tank at this time.)

• Use isopropyl alcohol, soapy water or a dry cloth when carrying out cleaning and
maintenance of the brake system. Do not use commercially-available brake cleansers or
silencing agents, as they can cause damage to parts such as seals.

• Do not remove the pistons when disassembling the calipers.

• If the rotor is worn, cracked or warped, it should be replaced.

• Parts are not guaranteed against natural wear or deterioration resulting from normal use.

• For maximum performance we highly recommend Shimano lubricants and maintenance
products.

M07S RESIN

In order to realize the best performance, we recommend that the following
combination be used.

Caliper

Brake Lever

Rotor

Hose

BR-M765

ST-M765

SM-RT77

SM-BH62/63

Mineral Oil

Brake pad
unit

Resin Pads

Metal Pads

SM-DB-OIL

M07-S

M06

Cable Supporter

SM-HANG

with the BR-M765 (calipers), ST-M765 (brake lever), SM-RT77 (rotor) and Shimano pad
unit.

• Obtain and read the service instructions carefully prior to installing the parts. Loose,
worn, or damaged parts may cause injury to the rider.
We strongly recommend only using genuine Shimano replacement parts.

• Read these Technical Service Instructions carefully, and keep them in a safe place for
later reference.

In the case of carbon handlebars, it may be
necessary to lower the tightening torque in
order to prevent damage to the handlebar.
Please consult the bicycle or handlebar manufacturer regarding the appropriate
level of tightening torque for carbon handlebars.

■ Wheel spoke lacing

Check that the spokes have been laced as shown in the illustration.
A radial assembly cannot be used.
Lace the spokes as shown in Figure 1 below for the left side of the front wheel
(the side where the rotor is installed), and the left and right sides of the rear
wheel, and as shown in Figure 2 below for the right side of the front wheel.

Rotating
direction of
wheel

Fig. 1 Fig. 2

Front rightRear left Rear rightFront left

Installation

The following tools are needed to assemble this product.

Tool

TL-LR15

Allen key 5 mm

Allen key 5 mm

Allen key 3 mm

8 mm wrench

Phillips screwdriver #1

Phillips screwdriver #2

Socket wrench 7 mm

Usage location

Rotor installation ring

Brake lever fixing bolt

Caliper fixing bolt / Adapter fixing bolts

Brake pad fixing shaft

Brake hose fixing bolt

Reservoir tank cover

Cable supporter

Bleed nipple

Brake lever Tightening torque:

6 - 8 N·m {53 - 69 in. lbs.}

■ Installation of the rotor
(SM-RT77)

Rotor
installation ring

TL-LR15

Tightening torque:

40 N·m {350 in. lbs.}

■ Installation of the brake lever (ST-M765)

Secure the brake lever as shown in
the illustration.