Motorcycles are relatively simple machines. As compared to cars, motorcycles have two fewer wheels, significantly fewer electronics, and so on. Despite the simplicity, motorcycle maintenance is still one of the items at the back of our heads that tend to pester at us incessantly. We fear a breakdown, we fear major repair expenses, and we fear that when we will need our bike the most, it may not be in shape for us.
So to clear the room of any wandering thoughts, we’ve decided to put together a comprehensive guide on motorcycle maintenance. Everything you might need to know and come back to when the thought of maintenance lingers at the back of your mind – everything from cleaning your frame to aligning your front wheel. If you’re looking to rid yourself of some riding and ownership anxiety, here’s everything you will need to know to keep your motorcycle healthy and running for your everyday needs and enjoyment.
Normally, engine oil is changed anywhere between 1500 kilometers to 5000 kilometers or more, or 2 months to 1 year, depending on the engine displacement, make, and model of your motorcycle. Engines without oil filters will need a shorter service interval, and more well-designed oiling systems may be more relaxed with service intervals. If your oil is running low, you may also need to top up for engine safety. This can be checked through the engine’s dipstick, filler cap, or sight glass, depending on the model of your motorcycle.
Conventional or multigrade oil is generally more affordable, but wears out quicker over time and will require shorter intervals.
Semi-synthetic oil is a blend of conventional oils and synthetic oils, which does not break down as quickly as conventional oil and is generally accepted as a great go-to oil type for most motorcycles.
Fully synthetic oil is generally more expensive but is also the most resistant to wear and tear. Be sure to check your owner’s manual for the recommended oil type since using one type or another may be detrimental to your engine’s performance.
Oil Filters and Strainers
Oil filters are designed to catch any particulates which get lodged inside the engine which are mostly small metal particles. Oil filters should be changed during every engine oil service interval. They do not need to be changed between service intervals, and conversely, oil filters must not be reused when new oil is placed inside the engine. Make sure to use the oil filter size and brand that is recommended by your owner’s manual or manufacturer, and be wary of the many fake oil filters available in the market.
Oil strainers must be inspected and cleaned every 2-3 oil changes. Strainers are designed to catch larger particulates, and may not necessarily need replacing every inspection – this would depend on your motorcycle and owner’s manual recommendation. Strainers must be cleaned either with a degreaser or brake cleaner, washed with water after, and fully dried before re-installing inside the engine.
Motorcycle coolant must be changed every 3-4 times your engine oil is changed, or every 1-2 years depending on riding habits. Coolant breaks down over time, just like engine oil, but does so in a slower manner, hence the more relaxed service interval. Nonetheless, it’s important to ensure that this essential fluid is replaced with the recommended specification from your manufacturer every year or two.
Coolant levels must also be checked regularly and can be inspected from the motorcycle’s coolant filler tank, typically found near one of the front fenders. If your coolant level is below the acceptable range, you must top up your coolant using the exact same specification as the coolant already found inside your motorcycle. If in case you do not have access to the necessary coolant, you may also top up only with distilled water, but must flush your coolant and replace it with fresh liquids not long after.
Filling up with the right fuel and the right amount of fuel is important as you need to make sure that your fuel pump is saturated with fresh gasoline all the time. Make sure that if you are going to use your motorcycle that the gasoline inside it isn't older than 3 to 6 months, otherwise, it's time to flush your tank and fill it up with a fresh tank of gasoline.
Regular fuel (91 RON), is the bare minimum for several countries, and it contains the least amount of octane. Better for low-performance engines that don't feature high compression ratios or heat output, regular gasoline fills in a need and is more affordable per liter compared to premium and super-premium fuels. Apart from that, it is also more common, especially in more remote areas.
Premium and super-premium fuel (95-100 RON) makes use of higher octane ratings, while less expensive fuel uses lower octane ratings. Octane is a measure of how well a specific fuel type can prevent engine knock, which is caused by high engine compression ratios, among other causes. In general, air-cooled engines do not need high octane fuels and most can run regular gasoline, while water-cooled engines may benefit from higher octane fuels. At the end of the day, the proper octane rating for your motorcycle will depend on the recommendation of the manufacturer. If you are uncertain of the octane rating necessary, consult your dealership or conduct a simple search in order to find out what’s best. The downsides of these types of fuel are that they might not always be available in gasoline stations that are in more remote areas and regions.
Fuel Pump and Injectors
The electronic fuel injection (EFI) system of your motorcycle is responsible for delivering fuel into your engine optimally using computers and electronic components. Regular maintenance on the EFI system includes fuel injector cleaning and fuel filter replacement. Over time, particulates from the fuel can accumulate on the fuel filter and on the nozzle of the injectors, causing a decrease in fuelling performance. As such, cleaning and replacement of these parts are typically done every 15,000 kilometers to 25,000 kilometers. Other components of the EFI system, such as the fuel pump and fuel lines will need replacement only if or when these parts break down. Fuel pumps should last the life of the bike, however, when it does break down, rebuilding, repairing, or replacing it are your options.
Maintenance on the carburetor generally includes tuning, cleaning, and gasket replacement.
Since the fuel mixture delivered by a carburetor is highly dependent on weather conditions and can typically go out of tune more often than EFI systems, carburetor tuning is recommended every 5,000 kilometers or every 6 months. This is to be done at a reputable service shop or at your manufacturer’s service center.
Carburetor cleaning should be conducted every 5,000 to 10,000 kilometers or every 6 months to 1 year. Cleaning the carburetor produces similar results to cleaning the injectors of an EFI system, ensuring that fuel delivery is optimal and without obstructions.
Carburetor gasket changes on the other hand must be replaced every 2-3 times your carburetor is cleaned. Healthy gaskets ensure that your carburetor will not leak fuel or air, which can potentially be troublesome for your engine health.
Spark plugs must be replaced every 5,000 to 15,000 kilometers depending on the engine requirement of your motorcycle, your riding style, and your fuel system’s health. Spark plugs generally have three different types: copper, platinum, and iridium.
Copper produces the strongest spark among all three, but also wears out quicker and requires shorter service intervals.
Platinum generally lasts longer than copper, and Iridium is the longest-lasting spark plug type. Switching between spark plug types will not be detrimental to the performance of your engine so long as you install the same specification of a spark plug as recommended by your owner’s manual.
Copper spark plugs generally need to be replaced every 3,000 to 5,000 kilometers, Platinum spark plugs every 5,000 to 10,000 kilometers, and Iridium at every 10,000 to 30,000 kilometers. Again, replacement intervals of the spark plugs as stated by the owner’s manual would be the most reliable source of service information. Make sure to change your spark plugs regularly to the recommended specification in order to maintain optimal performance.
Motorcycle air filters must be replaced every 5,000 km to 10,000 km depending on usage or the recommended interval of the owner’s manual. A simple visual inspection may also be conducted in order to determine if a motorcycle’s air filter will need replacement. The air filter is usually located under the seat and inside the intake airbox. Remove the screws or bolts of the airbox in order to access the air filter. In general, riding in dirty environments with a significant amount of air particulates will require air filter changes more often. This is why dirt bikes, dual-sport motorcycles, and adventure bikes typically have a shorter service interval as compared to street-only motorcycles.
Paper air filters are the go-to filter type in the market, which is often what is supplied with a motorcycle from the dealership. It is generally very affordable and produces good performance results for the motorcycle, however, you will need to replace this type of filter more often, and you also have to throw out the filter element after it is spent.
Foam filters generally allow for a greater amount of air to circulate into the intake system but also require cleaning and replacement more frequently. Foam filters allow your engine to breathe easier but could let in smaller bits of debris if exposed.
Washable air filters are the most expensive of the three, and make use of a variety of synthetic materials in order to trap dirt as well as a paper air filter, but are designed to be washed at every service interval in order to reduce long-term maintenance costs. Usually, these washable filters can either be dry or oiled depending on the manufacturer. Depending on the type as well, you can expect different cleaning methods whereas oil filters after cleaning will require you to reoil the filter element.
Valve Timing and Clearance
Ensuring proper valve timing and valve clearances allow for your motorcycle to draw in air and fuel properly while pumping out the right amount of exhaust gasses in a timely manner. Adjustments of valve timing and valve clearances are highly dependent on the type of motorcycle engine you have and the recommended interval from the service manual.
In general, valve timing and valve clearance adjustments must be conducted every 5,000 to 15,000 kilometers, or when a clattering sound on your engine becomes excessive. The latter can simply be diagnosed by covering your exhaust pipe with a towel and listening to the engine move. If a ticking or clattering sound is extremely loud, your valves will need to be adjusted for timing and/or clearance.
The clutch cable of a motorcycle will need replacement every 10,000 to 20,000 kilometers, or every 1-3 years depending on usage. Clutch cables will most definitely need replacement once the cable starts to fray, which will cause a heavier feel when pulling on the clutch lever. Cable fraying can be inspected at the lever or at the engine side of the clutch cable. Pull the lever in and out and pay attention to the health of the cable. If there are stray threads, your clutch cable is frayed and will need replacement.
Preventing fraying can go a long way. At every 1-2 engine oil changes, dismantle the cable at the side of the clutch cable and drip chain oil into the clutch cable. The oil must be inside the cable jacket and will serve to lubricate your cable effectively which will prevent unnecessary friction that may cause fraying. Simply add 5-8 drops of oil, which will be enough to last a few thousand kilometers of riding. An added benefit of clutch cable lubrication would be having a lighter clutch feel which would undoubtedly make your riding experience much smoother and less tiring.
Maintaining the clutch cable slack can be done through one end of the clutch cable at the clutch lever, or the other end by the engine. In general, your clutch should have a slack of about 4mm of free play measured at the section nearest your clutch cable on the lever. From a resting position pull in lightly until you start to feel the clutch lever resist the pull. Measure the distance your lever had to travel at the section nearest the clutch cable and adjust your cable accordingly to match around 3mm of free play.
Your adjustments can be made at the side of the lever, or at the side of the engine. For adjustments at the side of the lever, simply unlock the big lock screw nearest the lever, and adjust the barrel inwards for more slack, or outwards for less slack. If your lever cannot adjust for slack anymore, you may need to adjust the cable at the side of the engine. Crack the two nuts open and move the clutch cable frontward or backward to get the right slack specification for your motorcycle. Make sure to consistently check slack at the side of the lever for optimal results.
Clutch Lining or Clutch Plates
The clutch lining is often changed every 15,000 to 30,000 kilometers, depending on the engine requirements of your motorcycle and your riding style. Your clutch lining will need replacement if your clutch tends to slip more than usual. A motorcycle clutch is designed to mate the engine power output with the transmission almost instantly.
Riders may diagnose this by cruising at about 40 km/h at 5th gear, pulling in the clutch, revving the motorcycle engine up to near the redline, and releasing the clutch abruptly. If it takes about a second or longer for the engine RPM to go back down to the original cruising RPM, your clutch may be slipping and your lining will need replacement very soon.
When replacing the lining, your engine side cover will need to be pulled down. Ensure that the side cover gaskets and other o-rings or gaskets removed are also replaced with your lining in order to prevent oil leaks once the lining is replaced. After replacement, be gentle on the clutch for about 200 kilometers of riding since the clutch will need a break-in period to absorb oil and mate together optimally.
For manual transmissions, the transmission oil of your motorcycle shares the same oil as your engine. That being said, choosing the right oil for both your engine and your transmission will give you better performance and better protection.
For automatic transmissions, oil must be changed every 2,000 to 10,000 kilometers depending on the specification of your owner's manual. A good tip would be to change your transmission oil every 1-2 oil changes in order to keep your automatic transmission healthy.
To protect your transmission’s sprockets in the front and the rear, it is essential that you lube your chain frequently in order to reduce wear on the parts. Over time, your chain will eat away at the sprockets’ teeth, and in some cases, you can even break a tooth off if not taken care of. Eventually, when needed or after a long time, you will need to replace your motorcycle’s sprockets and also your chain.
The chain of a motorcycle can tell a lot about the owner. A well-maintained chain is one of the hallmarks of a well-maintained motorcycle. Chain maintenance includes cleaning and also lubing with the right products. The chain should be cleaned with a degreaser or even kerosene in order to loosen up any excess or old lubricant that could cause frozen links or damaged links. Your chain lube must then be applied after cleaning to make sure that all of the links move smoothly. Clean your chain after every seven days if you ride often, or at least once a month if you ride from time to time. If you end up riding in the rain, make sure to clean your chain after the ride or as soon as you are able to.
Chain tension is another item to adjust regularly. Over time, a motorcycle’s chain will stretch out, and to counter this, the rear wheel can be adjusted forward and back in order to put more tension or ease the tension on the motorcycles’ chain. This action allows the bike to increase the useful life of the chain. When adjusting your motorcycle’s chain, you don’t want too much tension as that could cause the part to snap since your rear wheel also moves up and down. Conversely, you don’t want the chain to be too loose otherwise it will get disconnected from the sprokets.
The front fork of a motorcycle generally has only two items that will need regular servicing, replacement of the fork oil, and replacement of the fork seals.
Fork oil has to be replaced every 20,000 to 30,000 kilometers or depending on the recommendation of the owner’s manual. Over time, fork oils can degrade due to the friction and heat generated by the movement of the suspension internals at every ride out. The recommended amount of fork oil for your respective front suspension will also depend on the recommendation of the owner’s manual.
On the other hand, the service intervals of fork seals will depend mostly on the failure of the fork seal itself. This will need replacement when the fork starts to leak oil. In order to diagnose this, simply run your finger over the parts of your motorcycle’s front fork after a ride out. If your finger catches a thin film of oil, your fork seal will need replacement as soon as possible. Fork oil will also need replacement every time a fork seal needs to be replaced. Don’t forget to use the recommended fork seal and fork oil specification recommended by your owner’s manual in order to keep the front suspension working properly.
Unlike the front forks of a motorcycle, rear shock absorbers generally do not have set service intervals and are often built to last the lifetime of the motorcycle. Despite this, motorcycle rear shocks are still subject to wear and tear and will need replacement when one of three symptoms are presented, a leaking rear shock, or a rear shock that does not have an optimal amount of sag, or uneven rear tire wear despite a properly aligned rear axle.
The first symptom is relatively easy to diagnose. Simply inspect your rear shock after a ride for any signs of oil leaks, which looks like discoloration around the swingarm mount or a very obvious oil leak that glistens over a flash of direct light.
The latter two symptoms are a bit more difficult to diagnose at home so it will be important to take your motorcycle to a shop every year to have your rear shock diagnosed. If any of the three symptoms are present, your motorcycle rear shock will need replacement. Make sure that the rear shock you will purchase is the exact same specification recommended by your owner’s manual, or an original part from your dealership or manufacturer.
Frame and bodywork
Your motorcycle’s frame is arguably one of the most important parts of your motorcycle. As such, regularly cleaning the frame is important to ensure that the health of your motorcycle will not deteriorate drastically over time. When cleaning the frame, simply use water from a hose and car shampoo or motorcycle-specific shampoo.
When cleaning off oil, road grime, and dirt from the various components of your motorcycle, make sure to use shampoo, a microfiber towel, and a light hand in order to prevent scratches that may eventually cause paint deterioration and rust. We recommend against using a pressure washer when cleaning your motorcycle since pressurized water may cause micro scratches and may even remove old paint easily during a wash.
Head bearings or t-post bearings are the bearings that allow your handlebars to move left and right very swiftly and easily.
For general maintenance, head bearings must be lubricated every 1-2 years. Motorcycle rides which often go through dusty and rainy environments will need maintenance more frequently. The task of lubricating head bearings can be quite technical so it would be best to take your motorcycle to a reputable service center for maintenance. Remember that your motorcycle has two head bearings, the upper bearing near the handlebar, and the lower bearing near the front fender. Both will need to be lubricated for optimal performance.
If your bearings are properly lubricated, and your steering still feels a bit strange, you may have worn out bearings. Symptoms of a bad head bearing include notchy steering from left to right or vice versa, a motorcycle that steers to the right or left when you let go of the handlebar, or a clattering sound when going over bumpy terrain. Make sure to replace your head bearings if any of these symptoms show, and use the recommended bearing specification from your owner’s manual.
Just like the head bearings, swingarm bearings will need lubrication every 1-2 years.
This job is also a bit more technical and will need the expertise of a reputable motorcycle service center. This will allow your motorcycle’s rear suspension to travel properly up and down, and will also lengthen the service life of your rear suspension. Replacement of the swing arm bearings will be necessary when your swingarm feels notchy when moving up and down, or when you start to hear a creaking sound when your rear suspension moves up and down. Again, take your motorcycle to a reputable service center for replacement of the bearings, and make sure to use the recommended specification from your manufacturer.
The side stand pivot or bearing of your motorcycle will need lubrication every 1-2 years. This can be done by a reputable service center, or you can do this at home. Put your motorcycle on a paddock stand, remove the swing arm spring, and proceed to dismantle the pivot area of your side stand. Lubricate the components with multi-purpose grease. Reinstall in the way you dismantled the swing arm, and you should be good to go.
Front Wheel Alignment
The front wheel of the motorcycle will need alignment every 2-3 years or after an accident. You will know that your front wheel needs alignment if your wheel is not perpendicular to the handlebar – your handlebar points straight but your front wheel does not. When this happens, simply untighten the lower fork tube clamps on the triple tree until loose, hop on your motorcycle, press on the front brakes, and pump down on the forks about 10-15 times. After this, get off your motorcycle and tighten up the lower fork tube clamps once again, and your front wheel should be aligned.
Rear Wheel Alignment
The rear-wheel alignment will need to be adjusted every time your chain slack or tension is adjusted when your motorcycle seems to steer to the left or right by itself when you let go of the handlebar or every 1-2 years for good measure. In order to adjust your rear wheel alignment, you may decide to have this done by a reputable service center, or at home if you have the right tools. First, loosen the axle nut of your rear wheel, then put your motorcycle’s swingarm on a paddock stand. Afterward, loosen the swing arm adjuster nuts, adjust for proper chain slack, and match the left swing arm measurement to the right. Tighten everything back up to the proper torque specification of the manufacturer.
Maintenance of the electronic system of your motorcycle must be conducted every 15,000 to 25,000 kilometers or 3-5 years.
In general, electronic maintenance includes inspection of all your wires, cables, plugs, and hardware to ensure that your electrical system is healthy and functional. If parts need to be cleaned, an electronic sensor cleaner must be used. Spray on the areas that will need cleaning and wipe any remaining dirt, oil, or grime out with a clean and dry microfiber towel.
Replacement of electronic parts such as plugs or cables can also be done, however, this would need the expertise of a trained technician. Be sure to have your electronics inspected and cleaned by a reputable technician or service center as this job is highly technical.
Regular maintenance for the handlebar switches includes inspection and lubrication of moving parts. This maintenance task must be performed every 10,000 to 20,000 kilometers, depending on usage and environmental factors.
When inspecting, make sure to check for cracks or chips from the plastic components. If any of these are found, your handlebar switch will need to be replaced in order to ensure the longevity of your electronic components.
Lubrication, on the other hand, will be necessary if any of the handlebar switches feel crusty or excessively notchy. Dismantle your handlebar switch assembly and locate the moving parts or pivot points. Grab a bottle of silicone grease and spray a very small amount onto the component. Flick the switch back and forth a few times in order to ensure that the grease is able to get into the tighter areas of the switch, wipe off any excess grease, and reassemble your handlebar switch accordingly.
Your motorcycle battery must be inspected every 5,000 to 10,000 kilometers or 1-2 years.
The first thing to check would be the battery terminals. Make sure that your battery terminals are fastened properly and are not loose. If you find any rust or deterioration on the metal components of the terminals, you may need to replace these parts or the battery itself in order to ensure that your motorcycle is adequately supplied with proper voltage.
The battery itself must be inspected during this time as well. Simply dismantle the battery from the motorcycle and inspect the battery case and the battery box on the motorcycle. Your standard starter, lighting, and ignition (SLI) battery and lead-acid battery contain fluids inside the battery case. If leaks are found on the battery case or on the battery box of the motorcycle, your battery will need to be replaced as soon as possible. Remember that battery fluids are highly corrosive and toxic, so make sure to clean this out from your hands and motorcycle with water and soap immediately, if found.
The last thing you would need to check would be the voltage of your battery. Motorcycle batteries should be able to hold at least 13.7 to 14.7 volts when your motorcycle is running, or should be around 12 volts before starting. If your motorcycle battery is testing at around 10 to 11 volts before starting or is at the low 13 volts when running, your battery will need replacement as soon as possible.
Rims and Tires
Cast Alloy Rims
Cast rims on a motorcycle need to be inspected every 2-6 months. When inspecting, pay attention to hairline cracks, bent rims, and other structural issues to the rim. Similar to spoked wheels, cast wheels can also be checked for misaligned rotation at a service center. If any of the above are present, cast rims will need to be replaced. Fixing the rim through heating, bending, or hammering is not recommended since this will directly and negatively affect the structural integrity of the aluminum rim.
Spoked rims generally need more maintenance attention than cast wheels. Rim alignment would be the primary maintenance task for spoked wheels and will need servicing every 5,000 to 10,000 kilometers, or earlier if the rider experiences jittery up and down movement from the rear or front of the motorcycle on a smoothly paved road. Alignment of spoked rims is a task that requires a significant amount of precision, therefore it would be best to take your motorcycle to a reputable mechanic or service center for proper alignment.
Motorcycle tires will need to be replaced when your tire tread sits flat on the tread wear indicator, when your tire has incurred severe structural damage, or when your tire reaches a service age of 5 years. When replacing your tire, be sure to fit a tire which has the same specification recommended by your manufacturer. If you would like to change your tire specification, the general principle is that wider or narrower tires can be placed but must not exceed +/- 10mm from the manufacturer’s recommended specification. At every tire change, the rim must also be balanced properly in order to ensure stability at speed.
Motorcycle tubes are typically found on most spoked wheel set ups, which consist of the outer tire which meets the road, and the inner tube which holds air for inflation. Tubes will need to be replaced every time a tire is replaced. It’s important not to reuse old tubes for new tires since tubes are designed only to last as long as the tire. If in case your tube was punctured or damaged, a simple patch up or vulcanizing job will allow your motorcycle to be used once again, but damaged tubes must be replaced as soon as possible after the repair. This is to ensure that your tube will not have any potential weak spots for trips where reliability will be most needed.
It doesn’t matter if your bike has the best engine in the world if it cannot stop properly. A motorcycle’s brake system a necessity. The system is comprised of your brake master, brakel lines, calipers or shoes, and brake rotors or drums. Your consumables, on the other hand, include brake fluid, brake pads or shoes, and even your brake rotors. On a motorcycle check your brakes as often as possible. Check your braking system every 1,000 kilometers or less.
Rotor Discs and Drums
Discs don’t need to be replaced as often as brake pads, however, they tend to get worn and warped over time because they heat up and are exposed to the elements at the same time. The rotors on your motorcycle are designed to go through multiple heat cycles and are often made of steel with holes drilled into them for cooling. Over time, you may experience stress fractures or rotor warping. Have your discs checked every 5,000 to 10,000 kilometers You can also resurface your rotors when you get your discs changed to make sure that your rotors contact points are smooth, or you can just buy a replacement.
Brake pads or shoes
Pads and shoes are the main wear component of your motorcycle's braking system, and there are signs that let you know when it is time for a change. Usually, pads will make an audible metallic sound when down to their last legs, and in worse cases, you will experience reduced braking performance or inconsistent or jerky brake action. On older motorcycles with drum brakes at the rear, you will also hear an audible metallic sound when your shoes are reaching the end of their life, or reduced braking performance is also a factor. One thing to note is that you need the proper size brake shoe and brake pad for your motorcycle in order to get it installed in your system. Check with reputable shops for your correct size and specification, and after you change your pads, it is also important to inspect your rotors for undesirable wear or damage.
The lines in your braking system serve as channels for the brake fluid to flow to and from the brake caliper's pistons, and there are two types of brake lines that have different types of maintenance
For rubber lines, make sure to inspect them after every service interval for any knicks and scratches that may compromise braking performance. A cut in the lines will result in reduced performance or no brakes at all since no fluid is reaching the caliper. Brake hoses generally last a long time, but for good measure, a thorough inspection is needed every 10,000 kilometers and replacement after 3 to 5 years.
Steel-braided lines, on the other hand, come standard on more high-performance motorcycles and brake systems and return a better feel, however, due to the large surface area and the steel that is used, it is imperative that you clean these hoses thoroughly to avoid rust and other types of corrosion. The principle is still the same with rubber hoses, meaning that you need to replace them every 3 to 5 years and inspect them every service interval.
Calipers are another key component of your motorcycle's braking system. They also need attention during your maintenance interval or whenever you need new pads. Whenever you conduct maintenance on your brake calipers, it is important to monitor the condition of your brake pistons. To do this, remove the pad and inspect the pistons without removing the brake hose. Inspect if the pistons are all level, and make sure that that all pistons are also evenly resting. If not, you need to have your caliper rebuilt or readjusted by an experience mechanic.
For your brake master, the maintenance that is most commonly conducted is a brake flush and brake bleed.
Flushing involves purging your system of old brake fluid. Doing this allows you to remove any potential blockages or contaminants in your motorcycle's braking system. Other that you also get an opportunity to put in new brake fluid which can be the same spec or higher than what you previously had.
Brake bleeding, on the other hand, involves the mechanic opening up the master cylinder and pumping the brakes over and over to remove all the air bubbles that may have formed in the brake lines or may have gotten through because of your brake fluid boiling.
The fluid that you put inside your motorcycle's braking system is important. Fill the system with the manufacturer's recommended fluid, or get a better grade fluid if you would prefer. Every 40,000 kilometers or 3 years depending on the grade of fluid you use, you need to replace your car's brake fluid with a flush.
DOT 3 is less resistant to heat and boiling but it doesn't absorb moisture as easily as the other fluids in the system. It works well for most street applications and it is also reliable enough to be used for daily commutes and low-maintenance machines.
DOT 4, meanwhile is more resistant to heat but is more prone to absorbing moisture.
Lastly, DOT 5 is the most resistant to heat but is rarer and harder to come by unless you go to a high-performance shop. Its moisture absorption is around the same as DOT 4.