Brake Pads

The GS500 has front and rear disk brakes. Disk Brakes utilise a high friction pad, that when activated by the rider, clamps the disk attached to the wheels. This slows down the rotational speed of the wheel, which in turn slows down the bike.
The kinetic energy of the bike is dissipated into the atmosphere from the heat generated by the friction between the disk and pad. This friction causes both the pads and disks to wear out and eventually require replacement.

Brake Pad Types

Organic materials were originally used on many older vehicles. Brakes made of these are softer than others, tend to wear out faster, and do not offer comparable performance. Look for "organic" in the product description. brake pads

Semi-metallic materials are made with a combination of organic materials and metals. They offer superior performance and last longer than organic pads. Most late-model vehicles require semi-metallic pads. They can often be installed on older cars and trucks that originally used organic materials. Look for "semi-met" in the product description. brake pads

Ceramic pads represent the latest in aftermarket brake pad design. They offer excellent performance and superior service life while minimizing brake dust and noise. If your vehicle requires semi-metallic brake pads, you can often upgrade to ceramic materials.

Brake Pad Ratings

Generally for road use brake pads are available in three types: FF, GG and HH, related to the friction coefficient of the braking material. HH offers more stopping power for a given force on the brake lever than the GG and they more than FF rated pads. But that doesn't make HH pads better - it's more a matter of balance, taste and riding style.

Some people find HH pads too 'grabby', especially on lightweight machines. Don't fit HH pads to the rear of the bike and GG to the front, this will make the overall braking balance too rear biased, which isn't good. However many people find the reverse: HH on the front and GG on the rear very comfortable and effective.

Many newer sports bikes should only use HH pads, so check the manufacturer's specifications. A noticeable downside to using HH pads is that they tend to wear the brake rotor more quickly due to their higher friction coefficient.

The ratings are determined by The Chase Test, better known as the SAE J866A test procedure. It provides a uniform means of identification that may be used to describe the initial frictional characteristic of any brake lining.

The Chase Test is used to assign a two character code (e.g. EE, FF, GG, HH, etc) to a specific friction formulation. These characters represent the coefficient of friction when a 1" square piece of friction material is subjected to varying conditions of load, temperature, pressure and rubbing speed on a test apparatus known as the Chase machine.

GS500 Brake Pads

FRONT BRAKE PADS
1989 - 1995 GS500's use the same front brake pads
1996 - 2009 GS500's use the same front brake pads (HH rated as standard)

REAR BRAKE PADS
1989 - 2009 GS500's use the same rear brake pads. (FF rated as standard)

Preferred Pads for the GS500

Many users have reported excellent braking performance by updating to HH rated pads for the front brake.
Many prefer GG rated rear pads on the street to help prevent rear lock ups. HH rear pads are recommended for track use.

EBC http://www.ebcbrakes.com

1989 - 1995
Front - FA129
Front HH - FA129HH
Rear - FA63
Rear HH - FA63HH

1996 - 2009
Front - FA231
Front HH - FA231HH
Rear - FA63
Rear HH - FA63HH

GALFER http://www.galferusa.com

Changing your Pads

Place the bike on it's centre stand.

The rear disks pads can be changes whilst still fitted to the bike. The front pads require you to remove the calliper (just two bolts). Don't allow the calliper to hang by the brake line. Either sit it on a small table top, or hang it from the bike with some wire. Otherwise you can remove it from the brake line (of course, you'd want to drain the brake fluid before doing this) and work on it off the bike.


DIY Changing the Front Pads.

1. With the bike on the centre stand, loosen but don't remove the front wheels axle bolt and loosen but don't fully remove the two brake calliper bolts that hold it to the fork.


2. Place a jack (use a piece of timber as a protective cushion) under the engine block and raise the front of the bike until the front wheel is off the ground. Make sure the rear wheel and the centre stand is touching the ground. Placing a heavy object on your rear passenger seat (three bricks on some cardboard) will help steady the bike.


3. Remove the front wheels axle from the wheel. Remove the callipers two bolts.


4. Slide the calliper off the rotor.

5. Remove the spilt pin from the bottom pin off the calliper.

Then slide out the pin.


6. Remove the old pads. Clean the inside of the calliper and especially around the pistons with an aerosol brake cleaner.

7. Remove the Brake Reservoir cap, nylon spacer and rubber diaphragm. (You may now wish to syringe out some of the brake fluid or open the bleeder nozzle on the calliper, attach a brake bleeder hose and pump some fluid out by squeezing the brake lever).

8. With the brake reservoir cap off, push the brake calliper pistons back into their recess with your fingers. You may need to use a mini g-clamp or some multi-grip pliers to push them back in. Use an old brake pad or a thin piece of wood to prevent gouging the piston). Pushing in the pistons will cause the brake fluid level in the reservoir to rise. (That's why lowering it first is recommended)


9. Take the metal shim from the back off one of the old brake pads. Clean it with brake cleaner, then fix it to the new pad. Clean both of the new pads front and back with the brake cleaner.


10. Refit the brake pads, the pin and its split pin.

11. Slide the calliper and new pads back onto the disk rotor. Put the wheel in place (remember to line up the speedometer unit and the spindle before trying to get the wheel to line up for the axle). Make sure the axle is clean then apply a thin layer of grease before sliding it back through the wheel. Hand tighten the axle nut. Hand tighten the callipers bolts.

12. Lower the jack, returning the bikes front wheel to the ground.

13. Further Tighten the axle and calliper nuts.

14. Bleed the brake system.

15. Pump the brakes a few times before riding to get the brake pads in position next to the disk. Do some slow speed braking to help bed the brakes in. Take it easy on the brakes for the next 160kms (100 miles).


DIY Changing the Rear Pads.

Below is a step by step process to changing the rear pads.

Remove the plastic cover cap.

Pull locking clips

slide out pins (holding down spring retainers)

While pulling that first pin out, push down on the springs with your free hand. If you don't, each spring will SPROING! as the pin clears it, and may even catch you in the eye.

Pull out spring retainer, then old pads and shims

New pads (top) compared to Worn pads (bottom).

The brake calipers piston may need to be pushed back in. This is easiest if the brake fluid reservoir is open. Often its best to drain the brake system completely to prevent brake fluid spills.

Since your new pads will be thicker than the old ones, you may need to retract the piston a bit. If you're feeling lazy, just use one of the old pads as a lever to force it back into the housing. (There must be a better way!). Otherwise use a mini g-clamp or some multi-grip pliers to push them back in. Use an old brake pad or a thin piece of wood to prevent gouging the piston)

Also, when you put the new pads and shims (don't forget them!!!) in they will want to fall right through the opening. You need to hold them in place with one hand (one pad at a time) as you thread the first pin through the holes with the other hand.

Push retaining spring down as you slide the pin back in.

Re-fix clips

Re-attach the disc callipers cover.

Now you should refill and bleed your brake system with new DOT 4 or DOT 5.1 brake fluid to ensure no air bubbles are in the system.

Part Numbers

http://www.bbburma.net/Documents/GS500_Brake_Parts.txt