Now that we’re all cooped up at home, it’s the perfect occasion to spend some time in the garage conducting basic bike maintenance. Bleeding brakes is something often left undone until you can’t stop as quickly as you should. So whether you are on top of your maintenance schedule or this is the first you’re hearing about it, this is a step by step guide bleeding your brakes.
Unopened Brake Fluid
Usually motorcycles need DOT4 or 5.1 brake fluid, but check your owner’s manual or the top of the reservoir for the recommended fluid type. DOT4 and DOT5.1 are interchangeable but NOT DOT5. DOT5 is a silicone based that is only used in specific applications. Another possibility is mineral oil, which will require a special blend recommended by the manufacturer. It’s important to use a fresh unopened bottle of DOT4 or 5.1, since brake fluid will go bad over time as it is exposed to air and absorbs moisture.
A bleed bottle is the container that will catch the used brake fluid as you bleed it from your brakes. You can either buy one at the auto parts store, or build one at home out of an empty bottle that’s at least 12 oz. I prefer a sturdy sports drink bottle with a wide mouth cap instead of the thin plastic water bottles that usually tip over easily. A disposable water bottle will work in a pinch if you have nothing else available. Next get about a 2-foot length of clear rubber hose (the clearer the better), and make sure the hose fits tightly over the bleed valve on your brake calipers. Drill a hole just big enough for the hose in the center of the bottle cap. Run the hose through it and tighten a few zip ties around the end of the hose on the inside of the cap to keep it from pulling back out. Finally, screw the cap on the bottle and you have a solid bleed bottle.
This should be obvious, make sure you have the proper tools for opening the brake fluid reservoir, cracking loose the bleed valve, and removing any panels that may be in the way. Most of the time you will just need a screwdriver and a combination wrench.
Rags, Gloves, Safety Glasses
Grab plenty of rags. You will need a few to cover potential spill areas and to wipe up any other unexpected drips. Plus it’s never a bad idea to have more than you need. Safety equipment is always a good idea. It really sucks getting things in your eye.
Brake Fluid Cleaner
This is a must even for experienced mechanics. Brake fluid is acidic, and will burn spots in paint and plastic. Simply wiping away a splash of brake fluid with a rag won’t get all of the fluid; you need to use a cleaner to make sure you get it all. Brake cleaner works well (as long as it doesn’t damage the surface you’re cleaning) but simple soap (Simple Green, dish soap, etc.) and water work just as well.
Grab a friend or family member that can follow simple instructions. If you don’t have anyone available, just grab a few long zip ties. They’re good at following orders.
Now that you have your supplies let’s get to work.
First make sure your bike is on a stable and level surface.
If you have a wheel chock or stands, that’s great. Take a look at your reservoirs (front and rear) as some bikes may have them mounted at an angle when the bike is upright. You want the reservoir to be as level as possible for this job. This may require the bike to be on its side stand and/or the handlebars turned one way or another. You may also have to adjust the bike’s position between working on the front and rear braking systems.
Let’s start with the front brake.
Take one of your rags and wrap it around the reservoir just below the cap to catch any splashes or drips. The brake reservoir is located on the right side of the handlebars, next to your front brake lever. Don’t confuse this with your clutch reservoir on the left side, assuming you have a hydraulic clutch. Remove the brake reservoir cap and expansion gasket, and place them on a clean rag. As always make sure that special care is taken with anything with brake fluid on it. We don’t want to damage anything. If your reservoir is low on fluid go ahead and top it off with fresh stuff.