Brake fluid replacing/bleeding:
Motorcycles have up to two brake fluid reservoirs, one for the front, usually found on the handlebars and one for the back. Both should be checked regularly. Topping up should only be done from a new, sealed bottle as brake fluid tends to absorb moisture over time.When the brake fluid turns from clear to a darker colour,its time to change the fluid.Beware - brake fluid, if spilt on paintwork eats right through the bare metal.
#When undertaking the process of bleeding brakes on your motorcycle, prepare by covering up the relevant components to prevent them being affected by brake fluid. It is a very corrosive substance that can quickly cause damage to surfaces that it falls onto.Cover the relevant bike parts with old rags and keep a bucket of soapy water to hand in case there is a spill so it is easy to quickly wash away.
#Be patient when bleeding brakes as it can take some time and you should avoid rushing it.The entire process of opening and closing the bleeder nut may need to be repeated several times to complete the task.
Make sure you have the following tools to bleed the brake fluid,
1)One bottle(250ml) of DOT3 or DOT4 brake fluid as per your choice.Here I am using Castrol DOT4 fluid.
2)10mm ring/open end spanner
3)8mm ring/open end spanner(for rear brake)
4)philips screw driver
6)a clear plastic tube for bleeding
For the FRONT brake:
Place the bike on centre stand
The CASTROL DOT4 brake fluid
Step1:Here is the master cylinder,we can see the Dot3 brake fluid through the window
Remove these two screws..
Remove the baffle and the diaphragm..
The old DOT3 fluid can be seen in the master cylinder..
Remove the cap above the bleeder nut and attach a clear tube to it,while the other end attached to the container so that the fluid can flow in it when the bleeder nut is loosened.
Make sure the reserviour(master cylinder) is filled so that no air enters the circuit.
Now loosen the bleeder screw a little using a 10mm spanner,you will see brake fluid coming out through the bleeder nut and to the tube.
Now press the front brake lever so the old fluid is forced through the tube into the container.But wait,Keep holding the brake lever completely and tighten the bleeder screw again to prevent air entering in the circuit AND then release the brake lever.This part in bold is very important!
Repeat step 3 & step 4 several times till you see clear DOT4 brake fluid coming out through the tube.Each time,you had to loosen the bleeder nut ,press the brake lever-the fluid will come out due to pressure,again tighten the bleeder nut and then only release the brake lever.
Step 5:Keep checking the reserviour after a few pumps,fill it till the brim,NEVER let it run dry.
After a few pumps,you will see clear DOT4 brake fluid coming through the bleeder nut.Now,loosen the bleeder nut again,press the brake lever and tighten the nut fully,release the lever.
Fill the master cylinder to required proportion,dont fill upto the brim as the rubber diaphragm will occupy rest of the place.
Put back everything in reverse order,remove the tube from the bleeder nut.
For REAR BRAKE:
Procedure is the same as above...
1)Never release brake lever with bleeder nutloose,it will suck air into braking system and degrade the braking efficiency.
2)When using a different grade brake fluid as in my case,make sure the entire brake fluid has been removed from the braking system
3)You must keep re-filling the master cylinder with brake fluid,it must never get empty.
4)Do not keep the brake fluid bottle open for too long as it will absorb moisture.
A word of warning: as with all home maintenance - and especially with something as critical to your safety as brakes - don't attempt the job unless you have got all the right tools to hand and you are confident enough to see it through!