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New Brake Pads Not Contacting Entire Rotor? Explained

When buying a new rotor with another brand and company from the brake pads, rotors would not make an exact and parallel contact with the pads and it needs adjusting and maintenance, look at the center line of the rotor and move the pads right or left region above the edges of the rotors, the greater width of the pads does not stay correctly above the rotors because they are larger and greater from the edges of the rotor and these would hit with the lower spider-like region of the rotors, the difference in rotor and pad size would matter a lot and these would make contact with each other.

Diameter and thickness would bring a large difference between Magura, Shimano, Vid, and hayes brakes and all of these have different contact surfaces with the rotors due to which contacting errors come between the pads with different brands of rotors. if you have chosen a random brand rotor for the front and rear wheel with a random caliper then you have to install the adapters to make both of them compatible with each other, installing adapters further misguide the caliper and rotors, change the position of the adapter for the correct alignment of the complete pads above the edges of the rotors.

Adapters are also smaller and bigger in size which also makes the calipers and rotors non-compatible, correct and accurate size adapters are also a must so that the inner diameter and thickness of the adapters would be compatible with the QR skewer and hub including disc brakes. mostly there are Shimano rotors which are limited for resin pads and if you use metallic and other material pads with these rotors then compatibility issues would again rise and the entire brake pad surface would not touch and rub against the rotors when pulling the levers of the disc brakes.

Brake pads contain small holes through which you can easily inspect the internals of the pads, pads also contain small cotter pins, if these pins are loose then these would start vibrating within the holes, and this issue is easily maintained by the mechanic, and skilled rider, you have to finish the vibration and movement of these pins for the correct alignment of these pads with the rotors. calipers contain their own sized nut bolts for threading them within the brake pads, larger or smaller sized bolts cause threading issues which increases the internal play of the rubber pads, as a result, pads start continuously moving and vibrating and do not stay on a single place with the rotors.

Small nut bolts and pins of calipers and brake pas are not interchangeable between the front and rear disc brakes. new brake pads mostly do not entirely in contact with the rotors due to the structure and new shape, but as time passes these would start adjusting themselves and their contact surfaces make full contact with the rotors, but if the rotors are old used or bent in shape, or if the rotor is out of true then it starts wobbling due to which it badly wear both sides of the pads in less time.

Bleed The Brakes Properly:

The main reason to bleed disc brake pads is to release all the internal air which is present within the brakes, this air is present within the initial parts of the brake pads, and the brake pads are responding very well, you have to open the valve of the calipers and brakes for bleeding to remove all the internal air, pull the levers of the brakes and also pull the pedal of the bike at the same time to remove all the internal air, finally when you notice the internal parts of the brakes are bled properly then release the brake levers and remove feet from bike pedals and close the brake opening valves thoroughly to prevent penetration of the atmospheric air within bike brakes.

The pistons of the brake calipers would stop working by the entrance of a small amount of air during the bleeding, you need to remove all the bubbles of air from brake parts when bleeding, and also there are special hose type long bleeding bottles which are used to bleed disc brakes. bleeding needs to be done properly any misguidance is not acceptable because these are the diss brakes that have modern braking systems as compared to old traditional rim brakes.

Master Cylinder Of Disc Brakes:

It is a small cylinder present within the brakes, all the internal brake fluid would come in contact with the master cylinder and fluid flow occurs by passing through these cylinders of all the disc brakes, sometimes the fluid flow stops reaching master cylinders due to which brake pads would not respond better, it only happens when these cylinders become old or these contain air and water which penetrates when these cylinders cause leakage due to crashing or scratching on the terrains.

Shifter From Existing Brake Brand To New Brand:

If you are using adapters for disc brakes and you are shifting and replacing an old used disc brake with the new one, then you have to buy a new adapter also so that it should be compatible with the new brakes, the old adapter is useless and also old mounting and clamp bolts are also useless for new disc brakes and rotors.

Servicing And Cleaning Of Disc brake Pads And Calipers:

Sometimes the brake pads would not respond better smoothly on the trails and they need proper maintenance, sometimes the inner surfaces of the brake pads are rusty, open all the brake pad setups including the calipers and remove the rust by using different rustproof products, soak in the liquid and rub with the toothbrush after pads become neat and clean.

Soak pins, clips, and brackets of the calipers and also threading bolts within the mixture of the rustproof material. sometimes the inner flexibility of the brake pads is negatively affected, due to which their working performance is affected badly and these would not work smoothly, if one-sided pad is smooth then the other side would not be normal, if one-sided pad is completely touching the edges of the rotors, then the other side would touch half the rotors.

Brake calipers contain pistons, if you cannot lube them properly a single time in a month, these would also start hanging and losing all of their function which also affects the contacting surface of the braked pads with the rotors.

Lube all the contact surfaces of the calipers, brake pads, and rotors which are metal surfaces to reduce friction between them.

Check The Internal Pressure Of The Disc Brakes:

Like tubeless tires, disc brakes are also pumped to maintain the internal pressure of the brakes to make contact with the brake pads with rotors thoroughly. it is common pressure of brakes to drop to lower levels and the brakes would not respond better. it happens if the seals of your disc brakes are poor and wear out, due to which all the internal pressure starts leaking through these rough seals, you have to change or replace these small brake seals, but there is also a compatible method, there are small washers used to cover and fix old or poor seals, so you have two choice, change the seals or buy washers for these seals to prevent the internal leakage.