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Last Updated: December 01, 2014

Motorcycle Front Brake Failure (front brake master)

Have ever been cleaning your entire brake system especially the front brake? Did u ever suspect that it needs an overhaul cleaning to make it  more effective? or Does anyone have a sticking front brake system? This page will tell you that often times which i forgot for many years, the front brake system must be inspected and clean for a more reliable braking system of our motorcycle. So dammed fool of not having it inspected for so many years, that even thought the system still works without cleaning, The pad sticks to the brake rotor causing my front wheel not spinning freely. And so let the tear down begin.

First is to drain all the brake fluid using a hose and an empty plastic bottle of soda. insert first the close wrench number 8 on the brake caliper drain plug bolt and insert the hose to it.

This is to ensure no FLUID will be getting on your precious magwheels and paint. (corrosive substance) and all fluid will get to the plastic bottle. By opening the drain plug bolt, we can now release the brake fluid out from the reservoir by pressing the brake lever on and off until none of the fluid is visible. If you have an extra bottle of DOT-3 brake fluid, you may pour it on the reservoir to push all dirty brake fluid at the hoses and caliper itself so that fresh fluid will be at the hose and brake caliper when putting it all together again. You can also do this procedure later.

 After releasing all fluid inside the reservoir, , it is very difficult to take it out. After minutes of trying to remove it, finally the piston is out. Since this is i think the second time it has been remove in a 10 year span, the fluid already corroded some of it, in lieu with those white powder.

it can be remove from the handle bar and put it on a bench table for rework and general cleaning and inspection. Now the hard part, without the so called
This is a very bad sign, and i think in need of replacement but then this is a DIY page, so i'll still be reusing all of the parts. It will just be clean and remove unwanted debris.

NOTE:  But for readers, it is highly advisable to replace the whole piston assembly with new one. This is to ensure your front brake will not fail. The replacement part is very cheap. You can buy one at every friendly local shop available.

Here is a diagram of every component of the front brake master.

Continuing with the tear down, when the circlip that locks the piston to chamber was remove, the piston can be pulled out from it.

Here we can see the entire piston set of the brake master and photo says it all, YUCKY!!! too much dirt and sediments all over it. I wonder how it still works with that kind of dirt.

close up, that is the view of not totally having a routine check on the entire front brake system of a motorcycle.

Note again to the readers: If you find yourself like this on your motorcycle front braking system, please be advise to change it entirely. Do not re use for fail safe system.

Continuing with the process of my cleaning saga.

With the piston removed from the cylinder, cleaning the master reservoir only needs cloth that is damp with brake fluid. (use only brake fluid, no water, no soap) i used old toohbrush with NYLON bristles on cleaning the entire reservoir. The rest of the picture will tell how bad is this brake master.

and after minutes of cleaning the debris inside the chamber and the reservoir itself..patience makes a lot of difference, ready for assembly and bleeding the entire front braking system on this 125cc motorcycle.

when inserting back the piston to the cylinder. make sure you drop some brake fluid, this will help the primary and secondary cup sealed with the cylinder and glide normally inside of it. Lock the piston with the Circlip double check if is placed inside the groove. then put the dust cap back in its place.

we are now ready for bleeding, the act of removing old fluid inside the hoses and brake caliper.

Pour in fresh brake fluid onto the reservoir, make it full as in full tank. Press and release in cycle the brake lever and see the fluid gets in the hose. When doing this you will see bubbles when you are pressing the lever on and off. this means that the fluid is getting in. Make sure you are topping up when it goes to low level..Continue press and release the lever until it has already a slight tension to it..BLEEDING will come next.

When the lever got any tension on it..(i think you'll be needing someone to press that lever or if u can reach the bolt down while pressing the brake lever, I can call you that you a FANTASTIC man.. :) lol.

1. As you are pressing the brake lever,
2. open the drain plug to release the tension and push the fluid onto the drain plug. When there is no more fluid coming out from the drain hose we fitted onto the drain plug..close it again.and release the and release again the lever to get another tension and do it again the procedure on bleeding.

Do that procedure until all old fluid came out and that new fluid is coming out already.This is a sign that new fluid is already onto the system and you will have a tension on that front brake lever..

Top the reservoir on the correct level and return the DIAPHRAGM, the set plate and the cover and bolt it..The entire front brake system is done.

Now when you did cleaned the system and the front wheel is not spinning freely. Then the brake caliper is locking and in need of cleaning. The common problem with sticking disc brake is that, it does not return to the idle state when the piston of the caliper pushed the brake pad to the rotor..ROD that connects the caliper to its bracket as shown

This is the job of those number in 10, 15, 9, and 8. It needs to be cleaned.

photo shown next is where to put new grease so that when the caliper push the piston towards the brake pad..the grease will the push back the caliper to the idle state and releases the pad that is in contact with the brake rotor.

Good luck to your cleaning saga!!!..I have speed but without healthy BRAKING system...SPEED KILLS..