Shimano bleeding is not a complicated process and just the levers of Shimano brakes need bleeding while SRAM brakes are much more complex and these have their specific bleeding kits because of the two different internal fluids in both of these brakes which have different characteristics and properties, Shimano kits are not used for SRAM brakes and vice versa.SRAM brakes have different steps for thorough and complete bleeding but Shimano bleeding is simply a single step, but following all the steps for bleeding of SRAM brake accurately, your brakes will perform much better than the Shimano brakes. the main purpose of the bleeding of both of these kits is to finish the internal air that is present within the brake fluids.
Shimano Brakes Bleeding Kit:
The main products and tools which are necessary for bleeding of Shimano brakes are given below:
- Small-sized Allen Key
- Plastic Glass and cup with a small hose for inserting within the holes of the levers after removing o rings with the Allen key
- Seven Millimeter Wrench
- Mineral Oil
- Shimano Syringes
- Syringe Holders
- Zip Tie
- Bleeding Funnel
- Funnel Stopper
- Compression Sleeves
- Caliper Bleed Cover
- Small Disposable Plastics
- Small 2mm to 3mm threaded adapters are used for holding the bleeding funnel at o ring levers and if you don’t have a funnel you can also use a recommended syringe for lever bleeding.
- Remove brake pads from the rear calipers of disc brakes and mount Shimano bleeding kit blocks with the caliper.
- Fill the Shimano rear syringe with the recommended brake fluid. it is not filled fully, 75% fluid in the syringe is enough for bake bleeding.
Clean the calipers, levers, and o ring bolts of the Shimano disc brakes with a rough rag cloth and give your bike a position to move the internal air bubbles instantly.
Lose the bolts of the levers to reposition the levers of rear brakes, levers have Downard positioning and angles, and bring the lever, so that the handlebar grips and levers would be parallel to each other.
Remove the dust cap or caliper bleed cover and attach the Shimano bleeding syringe. after filling a syringe with the Shimano hydraulic mineral oil attach the syringe to the caliper bleed cap.
Remove the o ring bolt of the lever with the help of the Allen key and fit the threaded adapter with the bleed funnel of Shimano recommended size for bleeding, remove the caliper bolt and adjust Shimano recommended syringe. fill the funnel fully with the mineral oil, and after that extract and fetch the mineral oil from the Shimano syringe from the rear side which is attached to the caliper. when the rear syringe fully fills with the mineral oil you will notice the funnel which is attached to the lever bolt would become totally empty. it is the process in which mineral oil which is filled in the glass cup from the lever would start traveling through the Shimano cables of the rear brakes and cables would bleed thoroughly.
Now the syringe is full of the mineral oil again apply force with the fingers on the Shimano syringe so that the mineral would start pumping and flow towards the front lever plastic glass cup. repeat the same process, fill the plastic cup fully and then syringe, after traveling mineral oil through the internal cables of Shimano brakes, the color of the mineral oil starts changing and the clear clean color of the oil becomes dirty and black which is the sign that Shimano brake cables need further bleeding, after repeating this process for several times, a stage comes when the mineral oil becomes neat and clean, it is the sign that bleeding of your Shimano brakes would have been completed.
Beeding of Shimano brakes would also start creating small bubbles within the glass cup and the syringe, these air bubbles are present within the brake cables, you have to bleed Shimano brakes fully as far as when the air bubbles stop appearing from the brake cables.
Squeeze and pull the levers of brakes and tight them with a zip tie or plastic strap, it allows the bleeding funnel of the lever to move the fluid downward towards the calipers.
SRAM Bleeding And Kit:
Remove the wheel safely and also remove the brake pads and rotor but make sure never to leak the bleed cover or nipple and bleed cap of the caliper, because the inner fluid is dot fluid and it affects the other parts of the brakes. A 2.5 hex key is used to remove the SRAM pads and also remove the retainer pad bolt.
Inserting Bleed Block:
Insert the bleed block on the bleed cover and also install the retainer bolt of the brake pad which was removed in the first step.
It is the third step, in which insertion of the syringe takes place, the syringe is made by fixing the bleed clamp on the threaded end of the syringe, using two syringes, and fixing the bleed clamps on both of their ends.
SRAM Dot Fluid:
It is the fourth step in which you have to insert the ends of clamp bolts within the SRAM dot fluid so that 75% of the syringe would be filled with the dot fluid. now 25% of syringes have empty space which contains air bubbles, you have to remove this air from both syringes by pushing the syringes with your fingers up and down, the direction of the open and threaded end of the syringe should be towards the sky to prevent the leaking of the dot fluid from the syringe.
Rotate the dial clamp of the lever in the opposite direction of the rotation on its final immovable stop. it increases the spacing of the grip of the handlebar and the lever of the SRAM brakes. you have to adjust the distance of 75mm to 80mm between the lever and the grip of the bar.
Remove The O-Ring:
In this step, you have to remove or unthread the o ring off the lever bleed screw, the tool used for unscrewing the bleed screw is given below:
T10 Torx Wrench:
after removing the bleed screw, you will notice a few drops of the dot fluid on the edges of the bleed screw on the lever, with the help of tissue paper or a rag cloth clean the lever from these drops.
Installation of the syringe:
Now mount the syringe within the bleed screw port and never push the syringe. all of this process is for the bleeding at the lever of the SRAM brakes, now it’s time to bleed at the caliper region of the SRAM brakes.
Remove the dust cap of the caliper bleed port. A 4mm hex wrench is used to unscrew the bleed port of the caliper. insert the 2nd syringe within the bleed screw of the caliper. now the syringe edge contains a small rotating adapter which has been closed till now, rotate this screw towards the opposite end to make a track and allow the fluid flow between the syringe and the caliper brakes.
Now its time to start bleeding from the lever, remove the cap of the syringe, hold the syringe in a straight position and start pushing the plunger of the syringe, you have to push the syringe in less than no time, because after removing the lever bleed cap, the air starts penetrating within the brakes, a sudden and quick push of the syringe would prevent the airt from inserting within the brake fluid.
Filling Of Caliper Syringe:
After pushing the lever syringe you will notice the other lower caliper syringe would start filling with the fluid and the quantity of the fluid in the lever syringe starts decreasing. repeat the same process two to three times until the color of the dot fluid within the lever syringe and caliper syringe would become fully clean and matches with each other.
Squeezing Of Lever:
While inserting the fluid from the syringes, squeeze and pull the lever of the rear brake and flip the brake cable to remove the air which is present within the brake cables. pushing and pulling the plunger of the syringe would remove the air bubbles from the fluid and syringes. it is time-consuming but it is a better way of bleeding to increase the working performance of the brakes for a long time.
Remove The Syringes:
Now remove the syringe from the lever and with the help of a rag cloth clean and wipe the lever and edges of the bleed screw port completely. install the lever screw with the help of a T10 Torx Wrench, after that remove the lower syringe of the caliper and thread the caliper bolt screw with the hex key. after tightening mount the dust cap or bleed cover. in the end, remove the bleed block and install the brake pads within the caliper by threading the retainer bolt. after the removal of the caliper syringe, you have to wash the caliper and pads with the help of spray water and clean the brake pads and caliper area to prevent the fluid from sticking on the brake pads and rotors.