Brake Primer

"Living Harmoniously with the Intruder Braking System"

I've been riding and building motorcycles for over thirty years, and that in no way qualifies me for "Expertship", but I have learned a few things along the way, the most important of which is "Flexibility". Motorcycles have changed a lot over my lifetime, and I have had to learn to change with them. I think they call that "Progress". I call it "Stress Management"

After two years on a 700 Intruder and a year on my new LC 1500 Intruder, I have finally learned how to live harmoniously with the infamous Intruder Braking System, and I hope that this "Brake Primer" will help some of the new owners of these fine machines find an inner peace with the evil disk brake gremlins.

The two most common evils of the Intruder brakes are short service life and two different noises; squealing and buzzing. This primer will hopefully shed some light on both subjects, and offer a few solutions, and as a bonus, we'll include service and replacement instructions complete with photos.


Most Intruder owners will tell you that the inner rear pad is the weakest link in the whole braking system. Some people barely get 3 or 4000 miles out of the inside rear pad. Front brakes in general do not have a service life issue. They will probably last at least as long as your tires, no matter how you treat them.

The almost universally accepted opinion regarding motorcycle brakes is that the rear brakes are much less efficient at stopping the bike than the fronts are. That used to not make much difference, since rear drum brakes had much more surface friction than their front disc counterparts. The extra friction surface area sort of made up the difference, and then some, so riders still relied rather heavily on the rear brakes, and many custom bikes did not even have front brakes at all.

Enter the rear disc brake you have a less efficient rear brake system comprised of an equal size caliper as the front, and all of a sudden, rear pads are vaporizing! It's no wonder! That puny little rear brake caliper has to be put under way more pressure than the front just to equalize the stopping efficiency. What's up with those inner pads? What you have to do now, is retrain your braking habits.

The front brake system on the Intruder line of bikes is more than ample to haul down the beast under most normal conditions. Try to learn to use the rear brake only as an assist to the front, and to hold the bike while stopped on a hill (when you need your throttle hand free). You might be surprised at how your front brake can handle just about all of your stopping needs. I ride mostly two-up, and rarely ever gear down to slow the bike when coming to a stop, and I hardly ever apply more than very light pressure to the rear with normal traffic stops.

(All Intruder Disc Brakes use the same pads)

In an effort to obtain somewhat longer service life for their pads, many people are changing over from the original metal sintered pads to kevlar composite pads. The most popular are the "EBC FA-103" pads. (EBC is the manufacturer). These pads are available from your local motorcycle dealer, or can be ordered from a few catalog companies, at an average cost of $24 per set (one wheel). Be aware that using harder pads may result in faster rotor wear. The same part number will fit both front and rear calipers.


Brake squealing is caused by vibration of the brake pads against the piston and other metal parts of the system. This vibration is a given, and cannot be eliminated, however it's resultant noise can be, by the implementation of one, or a combination of the following procedures:

High Temp Waterproof Brake Grease. The choice of professionals. Apply sparingly to the contact points where the piston meets the rear metal surface of the pad assembly, and to the holding pins. This grease "lubricates" the opposing vibrating surfaces, and therefore reduces or eliminates the resultant squeal. Be careful not to use too much, or get any grease on the friction surfaces, or you won't have any brakes. Brake pad grease can be purchased at most any auto supply store.

Composite Shims: For a dry fix, you may want too consider using a composite shim between the plate and piston. Some aftermarket brake pad manufacturers (Scandinavian Brake Systems 'SBS', for example) make an adhesive shim pad that is applied to the rear metal surface of the pad. This rubber/kevlar composite material "insulates" the piston from the pad, and therefore reduces or eliminates the squeal. Grease should still be applied to the holding pins. These shims are not re-usable, and therefore represent an additional but small expense to replacement pads. Order them from Dennis Kirk Part# 19-1268. Dennis Kirk Phone Number 1 (800) 328-9280 (The SBS manufacture number is: SBS Brake Pad Shim #9500) Cost is about $6.00 per set of four shims. Enough to do two wheels.

Bevel Cutting the Friction Surfaces: Somewhat controversial, the theory is that if you cut a 45 degree bevel to the leading edge of the friction material, that will reduce or eliminate the vibrations that cause the squeal. Opponents argue that this method is only marginally if at all effective, and that it unsafely reduces the available "working" friction surface. Use your own judgment here. I bevel cut mine, and couldn't tell any difference in stopping power. Unfortunately for me, it didn't stop the squeal on my kevlar pads either.

The LC's Missing Insulator: Earlier model LCs have a small "hockey puck" looking disk sitting inside the hollow space of the outer rear piston. The normal warranty fix from Suzuki for squealing and sticking rear brakes is to install one of these "insulators" on the inside piston as well. Later models come with both insulators. Read this Letter from Jim to learn more about the insulators, and how to get them and install them.

Other people have tried with some success to use anti-squeal spray, silicone goop, and duct tape to reduce the noises, but keep in mind that each one of these procedures has its own set of drawbacks, which only create greater problems with regard to damaging dirt accumulation and difficulty of pad replacement.


Intruder (and many others) front brake rotors are crossed drilled. This cross drilling allows for better cooling of the rotor, and pads, and creates a funny (and slightly annoying) high pitched buzzing sound. As the holes pass between the pads, air is compressed into them and then heats up and makes a tiny high pitched pop as they pass from the trailing end. This air also helps to "float" the pads from the rotor when not under pressure. The resulting buzz can be greatly reduced (with some loss of friction surface) by hacksawing two additional slots in the friction material. Stock pads come with a vertical slot cut into the center of the pads. Simply add two more slots, cutting the pad into four equal sections. Make your cuts about two thirds of the way into the pads and stop there. This way, when the buzz comes back, you'll know it's time to shop for new pads. Anti-Brake-Buzz Modification Drawing This does reduce the effective "working" surface of the pads, but they will still function safely, in my opinion and experience. My guess is, that adding the slots greatly reduces the heat expansion time for the compressed air, thereby reducing the volume of the final "pop". Alteration of brake pad friction surfaces is not sanctioned by any professional service department that might otherwise be held liable for performing "unsafe" alterations to your vehicle. This is strictly a do-it-yourself-at-your-own-risk alteration.

PAD REPLACEMENT INSTRUCTIONS - Text only version, for easy printing.

Dragon's PAD REPLACEMENT PHOTO SEQUENCE PAGE - For those who desire a visual reference.


Bleeding your brake system is not difficult, but can be frustrating if not done correctly and thoroughly. It's a simple matter of applying pressure with the lever or pedal, then release that pressure by opening the bleeder screw, then close the screw and release the lever/pedal to draw more fluid into the system. Be careful not to run the reservoir dry or you get to start all over!

If the reservoir has run dry, or you have "opened" the system for repairs, you may find it necessary to REVERSE BLEED the system, by forcing fluid in from the caliper, and chasing the air out the top. (Click the link for more information on reverse bleeding). Any time you remove a component of the system, you should use new compression washers at any banjo bolts, and, as if I needed to say it, use lots of rags for the mess and don't let any of it get on the bike!!


Bleeding the clutch is done exactly like the brakes, with the exeption of having to remove the large chrome "Derby" cover from the left side of the engine (the one with the vent hole in it). When you remove the screws that hold the cover on, be sure to support it with one hand and not let it drop, as your regulator/rectifier is attached to the inside of the cover and you will need to disconnect the large electrical plug before you can move the cover out of the way. Just hold the cover in one hand and reach behind it and pulll the plug apart.  

Just above and slightly forward of the gear shift linkage you will see the small round Slave Cylinder with its bleeder nipple on top (looks sort of like a brake caliper). You have some wires that are held close to the cylinder which may need to be loosened and moved out of the way temporarily, for easier access to the bleeder nipple.
  Now do yourself a favor. Before you replace the derby cover, lubricate both mating surfaces of the rectifier plug with some Di-electric grease to prevent the normal corrosion that occues here and kills your battery. You can get Di-electric grease from most any auto parts store, but you may have to ask for it because it comes in a very small tube.


There are a couple of items on the market that will make refreshing or air bleeding the system much easier.
1. MityVac vacuum tool, model number 6820. This tool attaches to the bleeder valve and sucks air and old fluid out of the system. Works well but keep a close eye on that reservoir!! Costs about $30 to $40, and is available from many auto discount stores and catalog companies, or direct from
2. SpeedBleeder Bleed Valves. This is a set of replacement bleeder valves for the brakes and clutch, and each one contains a tiny check valve, which allows the user to simply pump the lever/pedal and watch the drain tube. No alternate closing of the valve is necessary. Available from at a cost of approsimately $24.00 for a full set of three. The size(s) that you need for your application is as follows: Front and rear brakes SB7100. Clutch SB8125


There are three types of Brake Fluid available:
Plain old dinosaur brake fluid, Synthetic Fluid and Silicone Fluid.

Synthetic Brake Fluid can handle much higher operating temperatures, and is less prone to moisture accumulation than dino fluid and therefore makes a much better system fluid for motorcycles. It's relatively inexpensive, and will mix with dino fluid without harm, which makes it a simple changeover. Just push out the old fluid with the new synthetic fluid. No need to drain and clean the system. I personally use and recommend the use of Valvoline SynPower synthetic brake fluid. Available at most any Walmart or Auto parts store for about $6:00 per bottle (enough to flush your entire brake/clutch system twice).

Silicone Fluid should never be used in your motorcycle. It is not designed to work with the inner parts of your system and will not mix with dino or synthetic fluids.

Comic Relief
Moccasin's Brake Song

Mocc's Place