Giant MPH-3 Disc Brake System Model Year 2002

Owners Manual

June 2001.
Fixation calipers and rotors: International Standard Fully hydraulic disc brake system 2 piston closed system Brake levers with reach adjusters Pressure point & brake pad clearance adjustable on the fly Easy brake pad replacement Standard DOT 4 or DOT 5.1 brake fluid

Contents:

Warnings Mounting the brake system on the bicycle 2.1 Assembly of rotor 2.2 Assembly of brake lever 2.3 Assembly of hose 2.4 Assembly of caliper Post Mount (Manitou forks) 2.5 Assembly of caliper International Standard Adjustment 3.1 Pad clearance adjustment 3.2 Lever reach adjustment 3.3 Angle of the brake fluid reservoir Tightening torque Maintenance 5.1 General 5.2 Replacement of brake pads 5.3 Bleeding procedure Trouble shooting and -prevention

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Warnings
Please read this owners manual carefully. Improper assembly of the wheels or malfunction of the brake system may be extremely hazardous and could cause accidents, even fatal ones. Be sure to learn the proper braking technique and operation of your bicycle. Consult your professional bicycle dealer and this owners manual for this.
Giant recommends not using this system for any downhill competition. It is particularly suited for cross country use.
Giant advises to have your wheels laced by an expert mechanic. Improper tightening of the spoke nipples or thin spokes may result in deformation of the wheel and can cause serious accidents.
Protect vital parts of the bike from spilling brake fluid by holding a rag around the brake fluid reservoir, and use protective gloves and safety goggles when working with brake fluid. Brake fluid spillage (for instance on the rotor) can cause contamination of the brake pads.

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Mounting the brake system on the bicycle
Assembly of rotor Place the rotor on the hub flange taking care that the arrows on the internal part of the rotor are pointing in the direction of rotation of the wheel.
Mount the rotor with the six M5 bolts onto the hub with a T25 Torx key to a torque of 4 Nm. Tighten the bolts in a crossed pattern. Threads of new bolts have been coated with blue material that prevents that bolts come loose. TM Always use Loctite Primer (#7649) and TM Loctite blue Removable Threadlock (#242) or similar material on thread of these bolts during re-assembly.
Then install the wheel into the frame / front fork with the rotor at the left hand side and fix the wheel in the dropouts. Warning! It is essential that the disc is clean (free from grease or oil residues) to avoid contaminating the brake pads and to insure perfect braking. Grease can be removed from the rotors with a citrus based cleaner.

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Assembly of brake lever Place a complete brake lever assembly onto the handlebar.
Set the brake lever to the right position. Tighten the fixing bolt with a 4 mm. Allen-key. Recommended tightening torque: 6 Nm.
Blow compressed air into the grip through a small hole at the end and slide the grip over the handlebar.

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Assembly of hose
Length and attachment of hoses: The hoses have to be attached to the frame and fork so that they do not contact the wheel or tire, or interfere with the travel of the suspension or the action of steering. Use the bikes cable guides and zip ties to attach the hoses. Also be sure that the hose is not so long as to possibly snag on anything while riding. A hose that is too short may cause steering problems but can also cause strain on the hose which may result in the hose getting disconnected from the caliper of brake lever. For maximum efficiency of the system, it is very important that the hoses are without kinks and have the correct length. Changing the length of a hose should be done by an authorised Giant dealer. Zip-tie After assembling the brake lever, put the caliper (front brake) from the front side to the backside through the opening between left hand fork leg and front wheel and fix the caliper to the dropout (see: assembly of caliper). Fix the hose of the front brake to the front fork. Use zip-ties or other parts to fix the hose to the fork brace and the lower fork leg (left hand side). Fix the hose of the rear brake to the frame. Push the hose into the hose guides on the top tube and the left hand seat stay.

Zip-tie

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Assembly of caliper Post Mount (Manitou forks) 1. Assemble the front brake caliper to the Giant postmount adapter (see picture) and use a 5 mm. Allen-key to tighten the two M6 fixing bolts. Notes: - the lower bolt for the front caliper is shorter ! - watch the orientation of the GIANT logo ! - recommended tightening torque: 9 Nm. 2. Hold the postmount adapter with the front caliper close to the disc brake mount on the front fork / frame, with the rotor placed between the brake pads. Screw in the two M6 fixing bolts, but dont tighten them. The postmount adapter should be able to move. 3. Now squeeze the brake lever, so the rotor is clamped by the caliper. Use a 5 mm. Allen-key to tighten the M6 fixing bolts. Recommended tightening torque: 9 Nm. 4. Now you can release the brake lever.
Threads of new bolts have been coated with blue material that prevents that bolts come loose. TM TM Always use Loctite Primer (#7649) and Loctite blue Removable Threadlock (#242) or similar material on thread of these bolts during re-assembly.
Pull the brake lever to see if the brake pads are actuated well. Make sure that the brake pads are well centered and balanced. If the procedure has been followed well, the caliper (and brake pads) is set parallel to the rotor and the rotor is exactly in middle of the brake pads. If necessary, release the bolts that fix the postmount adapter to the front fork. Repeat the whole procedure mentioned above or just move the postmount adapter a bit. Dont forget to tighten the fixing bolts again.

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Assembly of caliper International Standard Hold the caliper close to the disc brake mount on the front fork / frame, with the rotor placed between the brake pads. Screw in the two M6 fixing bolts, but just a few threads. Note: the lower bolt for the front caliper is shorter! Now squeeze the brake lever, so the rotor is clamped by the caliper. The space between the caliper and the disc mount has to be filled up with washers. Make an estimation how big the gap is, so, how many washers are needed. Try ! For both the upper and the lower caliper fixing bolts. Example: If the gap is approx. 1 mm., you may need 4 washers of 0.25 mm. thickness.
Put the washers between the frame/fork mount and the caliper. Use washers of 0.25 or 0.5 mm. thickness for each bolt to set the caliper (brake pads) parallel to the rotor and to set the rotor exactly in middle of the brake pads.

Use a 5 mm. Allen-key to tighten the M6 fixing bolts. Note: the lower bolt for the front caliper is shorter! Threads of new bolts have been coated with blue material that prevents that bolts come loose. TM TM Always use Loctite Primer (#7649) and Loctite blue Removable Threadlock (#242) or similar material on thread of these bolts during re-assembly. Recommended tightening torque: 9 Nm.
Pull the brake lever to see if the brake pads are actuated well. Make sure that the brake pads are well centered and balanced. If the procedure has been followed well, the caliper (and brake pads) is set parallel to the rotor and the rotor is exactly in middle of the brake pads. If necessary, release the bolts that fix the brake caliper to the fork and remove or add washers. Dont forget to tighten the fixing bolts again.

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Adjustment
Pad clearance adjustment Turn the adjust knob of the brake levers brake fluid reservoir and pull the brake lever until you have found the best braking position for your hand (to set the pressure point of the braking system to personal preference). Turning inwards (clockwise): distance between the brake pads becomes smaller, so, smaller brake lever stroke required. Turning outwards (anti-clockwise): distance between the brake pads becomes bigger, so, bigger brake lever stroke required. Due to normal pad wear during riding, the clearance between the pads and rotor will increase. So, its important to check the adjustment before and during each ride. Brake pad wear can be compensated and brake pad to rotor clearance can be adjusted. Turn the adjust knob clockwise to bring the brake pads closer to the rotor. (Illustration: caliper, brake pads and rotor).
If youre not able to adjust the brake system to the desired braking point (position of your hand or brake lever blade when the brake pads engage the rotor), please check if the pads are worn out. If so, replace place them. If no, please consult your authorised Giant dealer.

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Lever reach adjustment Find out the best lever reach by using a 2.5 mm. Allen-key to adjust the screw as shown in the illustration. For big hands: turn clockwise / inwards to increase the distance between the handlebar and the lever blade. For small hands: turn anti-clockwise / outwards to reduce the distance between the handlebar and the lever blade.
Angle of the brake fluid reservoir The function of the small screw (see picture) close to the lever blade is setting the angle of the master cylinder. Use a 2 mm. Allen-key to loosen the screw and adjust the angle of the master cylinder. Note: Make sure that its possible to turn the adjust knob. If the adjuster touches the lever bracket (clamp), turning may be impossible ! After this, tighten the screw again. Screw Lever blade Note: Not too tight: Otherwise the master cylinder will be deformed. Tighten the screw just enough to fix the master cylinder.

Adjust knob

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Tightening torque

Lock screw brake fluid reservoir: 5 Nm. Bleeder: 8 Nm.
Lever - handlebar : 6 Nm.

Brake pads: 4 Nm.

Calipers - frame / fork: 9 Nm.
6 rotor fixing screws: 4 Nm.
Bolt Rotor fixing screws Lever fixing bolts Caliper fixing bolts Bleeder Brake pad fixing bolt Lock screw brake fluid reservoir
Tool needed T25 Torx key 4 mm. Allen-key 5 mm. Allen-key 10 mm. wrench 3 mm. Allen-key 3 mm. Allen-key - Pag. 11. -
Recommended tightening torque 4 Nm. 6 Nm. 9 Nm. 8 Nm. 4 Nm. 5 Nm.

Maintenance

General
Proper maintenance of a bike equipped with MPH DISC BRAKES is important to insure years of trouble free safe riding. Check by dealer. Take your bicycle to an authorised Giant dealer for periodic service and inspection of MPH braking systems. Parts such as brake pads, hoses and seals, can be adversely affected by use, dirt and ultraviolet radiation. The MPH brake system has to be checked by a dealer once a year or more often if the bike is used in extreme conditions. High-pressure. DO NOT use high-pressure water or air hoses to clean bike. This can force dirt into parts of the hydraulic braking system, which may cause damage. Brake fluid, lubricants on brake pads and rotors. It is essential that the rotor is clean (free from grease or oil residues) to avoid contaminating the brake pads and insure perfect braking. To avoid brake fluid spillage on the rotors or brake pads, causing contamination of the brake pads, it is advisable to cover the vital parts with a rag before maintenance of the hydraulic system is done, or when lubricating parts of the bike. If brake fluid comes in contact with paint or plastic bike parts, wipe it off immediately. If you get any brake fluid on the brake pads, discard them and replace with new pads. DOT 4 or DOT 5.1 brake fluid. The fluid in this braking system (use DOT 4 or DOT 5.1 brake fluid only!), besides possibly damaging the paintjob and some plastic parts on the bike, is extremely hazardous in case of contact with eyes or skin. Use protective gloves when working with brake fluid. We recommend to replace the brake fluid in the system at least every 2 years. This fluid naturally absorbs water, which will result in a lower boiling point for the brake fluid and can cause poor braking. Do not mix DOT 4 and DOT 5.1 brake fluid! The MPH brake sets have been filled by Giant with DOT 4 brake fluid. Washing and cleaning. After riding (off road) in the dirt, clean the bike (and the components of the braking system) as usual with water, soap, washing-up liquid, etc. Remember: do not use high-pressure water or air hoses. After washing the bike or riding in the wet, take the wheels out of the bike. If the wheels remain in the bike, water may stay between brake pads and rotors and cause corrosion. After wiping dry with a clean soft cloth, remove all dirt from the brakes with a soft brush. Thickness of brake pads. Check thickness of brake pads before every ride. Replace pads before they are worn down to the back plate to assure proper function and to prevent damage to the rotor. Adjust knob. By turning the big adjust knob on the fluid reservoir of the brake lever, it is possible to set the pressure point of the braking system to personal preference. Also, in the same way, brake pad wear can be compensated and brake pad to rotor clearance can be adjusted. If the knob is turned clockwise but the space between the brake pads and the rotor remains too much (the brake lever has to be pulled too far), the brake pads have to be checked for wear.

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Check tightening torque. Tightening torque of fasteners and bleeders has to be checked frequently. Loose bolts may cause that parts come off, a loose bleeder may cause the braking system to leak. This can lead to severe injury or death. Loctite. TM TM Always use Loctite Primer (#7649) and Loctite blue Removable Threadlock (#242) or similar material on thread of fixing bolts of calipers and rotors during re-assembly.

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Replacement of brake pads
When to change ? Before each ride, check the wear pattern of the pads (both front and rear). The back plate of the brake pad should not touch the rotor. Replace the pads if there is not enough material left, or if high frequency noise occurs during braking. 1. To replace brake pads it is necessary to take the wheel out of the frame / fork. 2. Use a 3 mm. Allen-key to unscrew the brake pad fixing bolt of the caliper. Unscrew the small screw only (3 mm. Allenkey). DONT LOOSEN THE 2 BIGGER SCREWS (5 MM. ALLEN-KEY) BECAUSE IN THAT CASE THE WHOLE CALIPER WILL COME APART AND LOOSE BRAKE FLUID !!! DO NOT LOOSEN 3. Then, remove the pads.

DO NOT LOOSEN

Loosen
4. Turn the adjust knob of the master cylinder anticlockwise. At least 10 full turns. 5. Using a brush, clean the inner cavity of the pistons to eliminate any deposits and trace of dirt. 6. Insert two new pads inside of the caliper, put the brake pad fixing bolt back into the caliper and tighten it to a torque of 4 Nm. Warnings: - If the bolt is not tightened well, it can cause a hazardous situation. - Do make sure the bolt goes through the hole of each pad. 7. Turn the adjust knob of the master cylinder clockwise until you see theres no clearance between brake pads and rotor. 8. Turn the adjust knob of the master cylinder anti-clockwise and pull the brake lever until you find the best braking position on your hand.
Note: Do NOT use MPH brake pads model year 2000 (2 holes in each pad). These pads do not fit into the MPH-2 (model year 2001) and MPH-3 (model year 2002) calipers. - Pag. 14. -

Bleeding procedure

When to bleed ? Whenever the system lost brake fluid or air came into it. For example: After replacement or disassembly of : brake lever or caliper or hose or bleeder After shortening a hose Lack of brake fluid in MPH brake system due to leakage Replace brake fluid for MPH at least every two years When the braking systems feels spongy, perhaps there is air inside the hydraulic system. Advice: Its better to remove wheels and brake pads before working with brake fluid. Leakage of brake fluid on brake pads or rotor will ruin these parts.
1. Turn the adjustment knob of the fluid reservoir on the brake lever anti-clockwise all the way to create max. volume inside the reservoir. At least 10 full turns.
2. Use a 3 mm. Allen-key to unscrew the M5 lock screw from the master cylinders fluid reservoir. Remove screw, cap and O-ring.

3. Connect the short, transparent tube on the fluid reservoir / master cylinder, by screwing the connector (brass colour) in the threaded hole for the lock screw. Do this by hand and no too tight. Don't use a tool. If it's too tight, the connectors rubber O-ring will be deformed too much and it will leak air and fluid.

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4. Fill the syringe with DOT 4 or DOT 5.1 brake fluid from a new bottle: Put the syringe in the bottle with the nozzle under the fluid level and pull the piston of the syringe. Use DOT 4 or DOT 5.1 brake fluid only. DOT 4 and DOT 5.1 brake fluid should not be mixed. Make sure that the syringe is filled with the same kind of fluid as in the brake system. The MPH brake sets have been filled by Giant with DOT 4 brake fluid.
5. Push the syringe on the open end of the short transparent tube.
In case most of the brake fluid is still in the MPH disc brake system (for example after shortening a hose or switching front- and rear brake from one side from the handlebar to the other) skip step 6 to 10 and continue with step 11. Otherwise, if there is no or almost no brake fluid inside the MPH disc brake system (for example when replacing all the brake fluid once per year or 2 years, or after complete disassembly of the caliper and/or the master cylinder), continue with step 6. 6. Take the bleeder cover (rubber cap) off from the calipers bleeder and mount the second (long) transparent tube. Put the other end of this tube into a bottle or cup that can contain brake fluid.
7. Unscrew the calipers bleeder just a bit with a wrench 10 mm. ( to turn).
8. Start squeezing the syringe and don't stop squeezing until it is mentioned in this manual (step 10).

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9. While squeezing the syringe, pull the brake lever fast and release the lever slowly. New brake fluid will come into the hydraulic circuit eliminating most of the air that maybe in there. Continue until the fluid flow from the calipers bleeder through the long transparent tube is not any longer interrupted by air bubbles. If necessary, re-fill the syringe during this process. When doing this, close the bleeder (on the caliper) and dont open it before the re-filled syringe is connected to the fluid reservoir and the syringe is squeezed again.
10. With the syringe still squeezed, retighten the bleeder. Now, squeezing the syringe can be stopped. Remove the long transparent tube and put the rubber cap back on the bleeder. Tightening torque bleeder: 8 Nm.
Step 6 - 10 will take approx. 5 minutes, but in most cases it's not necessary, because there is still brake fluid in the hoses, levers and/or calipers. So, in those cases, you can skip these steps and continue from this point. And now the fine-tuning can start: the MPH system has to be made 100% air-free. This will take approx. 10 - 15 minutes.

11. Keep the calipers bleeder, etc. closed. No need to touch the caliper. Make sure that the adjustment knob of the brake fluid reservoir (brake lever) is turned anti-clockwise completely. The syringe should be filled for at least 25%, and connected to the brake fluid reservoir on the brake lever. The filling hole of the brake fluid reservoir should remain the highest point and the brake caliper the lowest point of the MPH system until the end of this procedure. So, air can go up in the MPH system and escape via the short transparent tube into the syringe. Brake fluid will go down into the MPH system. The syringe should be kept in upright position.

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12. By pulling the brake lever fast and releasing it slowly (the brake lever will pump the air up and the brake fluid down) and by tapping on the MPH brake hose, the air bubbles will go up. Via the short transparent tube and via the brake fluid in the syringe, the air bubbles will go out of the MPH brake system. This can be checked visually very easily. Don't squeeze the syringe!
13. While pulling the brake lever and releasing it frequently, turn the adjustment knob of the brake fluid reservoir clockwise (in) and anti-clockwise (out) a few times, to push the last bits of air out of the reservoir. Turn the knob all the way in and out, approx. 10 full turns.
14. If no air-bubbles come up through the brake fluid column in the syringe any longer, we can assume that the MPH system is 100% without air. 15. Turn the adjustment knob of the master cylinder anti-clockwise all the way, to have the largest brake fluid volume inside the reservoir. At least 10 full turns.
16. Disconnect the syringe from the small transparent tube and unscrew the connector from the brake fluid reservoir.
17. Turn the adjust knob of the fluid reservoir clockwise carefully, until you see the oil appear in the small hole for the lock screw.

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18. Reinstall lock screw, cap and O-ring. If the small lock screw is screwed in, there should be no air left in the reservoir. A little bit brake fluid will be spilled. Use absorbing paper or a rag to remove this.
19. Tighten the lock screw well into the master cylinder. Recommended tightening torque lock screw: 5 Nm.

20. Pull the brake lever and check the function of the MPH brake system: both sides actuated, disc in center, correct distance brake pads to rotor ?
21. Turn the adjuster, pull the brake lever and check the function of the MPH brake system again. Repeat step 20 and 21 until the function is okay.
Warnings ! F To avoid brake fluid spillage on the rotors or brake pads, causing contamination of the brake pads, it is advisable to cover the vital parts with a rag before proceeding and to take out the wheels.
F If the bleeder is not sufficiently tightened when using the disc brake, brake fluid may leak on the
rotor, causing loss of friction between brake pads and rotor. This can have serious consequences for the rider.
F Protect vital parts of the bike from spilling brake fluid by holding a rag around the fluid reservoir.
Brake fluid is hazardous and aggressive and damages not only your skin, but the paintjob and plastic parts of the bike as well. Use protective gloves and safety goggles when working with brake fluid.
F Once there is brake fluid or lubricants like oil, grease, Teflon and silicone spray on the brake
pads, they are worthless: no more brake function. So, don't forget to protect brake pads and rotors when working with brake fluid or lubricants. Or, even better, remove these parts.
F Use DOT 4 or DOT 5.1 brake fluid only. DOT 4 and DOT 5.1 brake fluid should not be mixed !
The MPH brake sets have been filled by Giant with DOT 4 brake fluid. - Pag. 19. -
Trouble shooting and -prevention
When riding down a slope, continuous braking with MPH disc brake will generate a lot of heat. The heat will be conducted to the brake fluid. The temperature of fluid can increase up to 120 C. or more. As shown in the illustration, the stroke of brake lever will become shorter. When this happens, the rider MUST stop riding to let the brake system cool down. No liquid shall be used to cool the brake components. That will lead to distortion of the rotors and change the characteristics of the materials. Meanwhile, the rotors and the calipers should NOT BE TOUCHED, because they can be very hot. Short
If the rider keeps using the brakes, the brake fluid will be heated to 150 C. or more. Then the brake pads will wear out very quickly. If the pads are worn, the brake force is decreased, even if the brake lever is pulled completely to the handlebars (see illustration on the left). This is extremely dangerous.
After the temperature has reduced, the adjuster on the brake lever can be turned clockwise to bring the brake pads closer to the rotor (to compensate the pad wear out).

Parts:

Brake pads

When to change?

How to change? Remarks:
Before each ride, check the wear pattern of the pads (both front and rear). The back plate of the brake pad should not touch the rotor. Replace the pads if there is not enough material left, or if high frequency noise occurs during braking. See: Maintenance; replacement of brake pads. Only use MPH genuine parts. Do NOT use MPH brake pads model year 2000 (2 holes in each pad). Two pads must be replaced at the same time. - Pag. 20. -

Rotors

max. 0.3 mm. When to change? If, after assembly to the hub, the rotor is not straight (more than 0.3 mm. out of line). If there are serious damages on rotor surface that lead to longer braking distance. See the instruction Mounting the brake system on the bicycle. Only use MPH genuine parts. Replace the six rotor fixing screws as well. See Mounting the brake system on the bicycle; assembly of rotor: six fixing screws should be tightened in a crossed pattern. TM Loctite (or a similar product) has to be used.

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Calipers
Brake fluid holes choked up, two pistons do not work properly at the same time. Brake fluid leakage due to seal failure. Malfunction of calipers. This should be done by your authorised Giant dealer. Only use MPH genuine parts. Use washers (0.25 mm. thickness) to adjust brake pads parallel to rotors and to set the rotors exactly in middle of the brake pads. TM Loctite (or a similar product) has to be used. Note that there is difference between front and rear calipers. Watch the orientation of MPH characters:

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Brake lever
Brake fluid holes choked up: the adjuster does not work. Brake fluid holes choked up: the piston does not work properly. Brake fluid leakage due to seal failure. The clamp doesnt fix the master cylinder effectively. Mal-function of brake lever. This should be done by your authorised Giant dealer. Only use MPH genuine parts. Note that there is difference between right and left brake lever. Small parts are the same, but the way these small parts are assembled is different.

Brake fluid

After replacement of : - brake lever or - calipers or - hose or - bleeder Lack of brake fluid in MPH brake system due to leakage. Replace brake fluid for MPH at least every two years. See Maintenance; bleeding procedure. For safety reasons, its better to leave this to your authorised Giant dealer. Only use MPH genuine parts. Use DOT 4 or DOT 5.1 brake fluid only. DOT 4 and DOT 5.1 brake fluid should not be mixed ! The MPH brake sets have been filled by Giant with DOT 4 brake fluid.

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Hose leakage (e.g. due to impact). The connector / connector nut can't be tightened, resulting in brake fluid leakage. 3. At least after two years use. This should be done by your authorised Giant dealer. 1. Only use MPH genuine parts. 2. Use two copper washers at both ends.

Bleeder

When to change? How to change? Remarks:
1. Bleeder loosened and tightened more than 5 times. 2. Cant get air out of system when bleeding. See Maintenance; bleeding procedure. For safety reasons, its better to leave this to your authorised Giant dealer. 1. Only use MPH genuine parts. 2. Make sure that the threads are completely coated.

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