Brakes

Front Brake Maintenance

The CB 450 front brake is a hydraulic operated caliper/disc type. This type brake will provide reliable operation and excellent braking qualities at much higher operating temperatures than the drum type brake.

When the brake lever is applied, brake fluid transmits the pressure to the brake piston in the caliper, pressing the friction pads against the disc. Brake fluid is a medium for transmitting pressure and plays a vital role in the brake system. Therefore when the scheduled brake maintenance is performed, it is imperative that the front brake system is inspected to insure that there is no fluid leakage.

As the friction pads wear, additional fluid is taken into the system from the fluid reservoir to compensate for the friction pad wear. Because of this feature, the disc brake is self adjusting and the brake control lever free travel will remain constant once the free travel has been established and providing the hydraulic system is free of air.

If the control lever free travel becomes excessive, and the friction pads are not worn beyond the recommended limit , there is probably air in the brake system and it must be bled.

Replenishing Brake Fluid

The brake fluid level in the reservoir must be checked at regular intervals as in the MAINTENANCE SCHEDULE and replenished whenever the level is below the level mark engraved inside the reservoir. Remove the reservoir cap (1) and fill the reservoir to the lever mark. Use only brake fluid which is designated "DOT 3" on the container. "DOT 3" brake fluid meets the SAE J1703 specification. Outside the U.S.A., Use SAE J1703 brake fluid. Tighten the reservoir cap securely.

   

 

Bleeding the brake system

The brakes must be bled with great care subsequent to work performed on the brake system, when the lever becomes soft or spongy or when lever travel is excessive. This procedure is best performed by two mechanics.

  1. Remove the dust cup from the bleeder valve and attach bleeder hose (3)
  2. Place the free end of the bleeder hose into a glass container which has some hydraulic brake fluid in it so that the end of the hose can be submerged.
  3. Fill the reservoir with only the recommended brake fluid. Screw the cap partially on the reservoir to prevent the entry of dust.
  4. Rapidly pump the brake lever several times until pressure can be felt. Holding the lever tight, open the bleeder valve by about one half turn and squeeze the lever all the way down. Do not release the lever until the bleeder valve has been closed again.
  5. Remove the bleeder hose, tighten the bleeder valve and install the bleeder valve dust cap.
  6. Do not allow the fluid reservoir to become empty during the bleeding operation as this will allow air to enter the system again. Replenish the fluid as often as necessary while bleeding.
  7. Check the effect of bleeding and absence of leaks in the front brake lines while holding pressure against the brake lever.

Replenish fluid in the reservoir when bleeding is completed. Reinstall the diaphragm, washer and reservoir cap and tighten.

When the hydraulic brake system has been drained, it should be first filled as outlined below.

  1. Fill the fluid reservoir.
  2. Open the bleeder valve by one half turn, squeeze the brake lever, close the valve and release the brake lever. This procedure must be repeated in this sequence until hydraulic fluid begins to flow through the bleeder hose. Having filled the hydraulic system with fluid, proceed with the actual bleeding operation.

NOTE:

Brake Pads:

Brake pad wear will depend upon the severity of usage, type of driving and condition of the roads. It may be expected that the pads will wear faster on dirty and wet roads. Visually inspect the pads during all regular service intervals to determine the pad wear.

The remaining thickness of pad linings can be determined by measuring the clearance between the face of the caliper inner housing and the brake disc by pressing the inner housing toward the disc. If the clearance is less than 0.12 in. (3.0 mm), replace with new pads as a set.

 

NOTE: Use only HONDA genuine replacement friction pads offered by authorized HONDA dealers. When service is necessary on the brakes, consult your HONDA dealer.

Brake Caliper Adjustment:

Whenever the brake pads are replaced, the brake caliper (1) must be adjusted. This adjustment is made in the following manner, so there is a small clearance between the fixed friction pad and the brake disc.

  1. Raise the front wheel off the ground using a suitable prop.
  2. Loosen the caliper stopper bolt lock nut (2).
  3. Using a suitable screw driver, turn the stopper bolt (3) in direction (B) until the friction pad contact the brake disc. When the wheel is rotated, some resistance should be noticed.
  4. While rotating the front wheel, turn the stopper bolt in direction W until the front wheel rotates freely.
  5. Turn the stopper bolt in direction (A) 1/2 turn further and tighten the lock nut.

 

Rear Brake Adjustment

  1. Raise the rear wheel off the ground by placing the main stand under the motorcycle.
  2. Rotate the rear wheel by hand and note the distance of the pedal tip travel (2) before the brake holds.
  3. Normal free travel is 0.8-1.2 in. (20-30 mm). If adjustment is necessary, make the adjustment by turning the rear brake adjusting nut (3). Turn clockwise for less free travel, counterclockwise for greater free travel.

    

 

NOTE: Make sue that the cut-out on the adjusting nut is seated on the brake arm pin after the final adjustment has been made. If the rear wheel assembly has been moved forward or rearward, during drive chain adjustment, the rear brake may require adjustment. Whenever the rear wheel is removed, examine the brake shoes for lining thickness and even wear.

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