WEBVTT Kind: captions Language: en 00:00:01.054 --> 00:00:03.436 A rubbing disc brake is a common problem, 00:00:03.436 --> 00:00:05.572 andandnbsp;even the slightest rub, 00:00:06.095 --> 00:00:09.609 which might not really be slowing you down, can still be annoying. 00:00:10.005 --> 00:00:13.320 This is hydraulic disc brake alignment, and regardless of brand or model, 00:00:13.320 --> 00:00:15.738 thisandnbsp;video will help you get rid of that pesky rub. 00:00:18.415 --> 00:00:20.763 Hey, I'm Truman with Park Tool. 00:00:20.763 --> 00:00:23.833 Hydraulic brakeandnbsp;alignment is a relatively simple procedure 00:00:27.533 --> 00:00:31.014 But there are other things that can causeandnbsp;the pads to rub 00:00:31.014 --> 00:00:33.351 so we're gonna start with diagnosing the problem, 00:00:33.351 --> 00:00:36.207 and then we'll takeandnbsp;you step by step through the alignment process. 00:00:36.468 --> 00:00:41.513 If you have mechanical brakes, which are actuatedandnbsp; by a cable, see this other video for alignment. 00:00:42.083 --> 00:00:44.023 Typical tools and supplies include: 00:00:44.023 --> 00:00:46.922 4 or 5 mm hex wrenches, or a T25, 00:00:47.143 --> 00:00:50.147 Also a torque wrench such as a TW-5.2, 00:00:50.333 --> 00:00:52.892 A light source to backlight the caliper, 00:00:52.892 --> 00:00:56.328 And a repair stand, or some way to holdandnbsp; the bike up while spinning the wheel. 00:00:59.900 --> 00:01:05.436 First we'll elevate the bike, spin the wheel, andandnbsp;sight the gaps between the rotor and pads. 00:01:05.436 --> 00:01:07.927 Back light the caliper to make it easier to see. 00:01:07.927 --> 00:01:11.343 This is a good time to give the pads a quick visual inspection for wear. 00:01:11.343 --> 00:01:14.046 These pads haveandnbsp;lots of life left 00:01:14.046 --> 00:01:16.021 but these other pads need to be replaced. 00:01:16.021 --> 00:01:20.511 See this other video to learn how toandnbsp; measure the wear, and replace the pads if needed. 00:01:20.511 --> 00:01:24.860 Back on our spinning wheel, we see there is noandnbsp; rub bewteen the rotor and pads. 00:01:24.860 --> 00:01:28.335 So in this case we would consider ourselves done with the alignment. 00:01:28.335 --> 00:01:32.743 And in this example there is slight rotor rub, and there's barely any noise... 00:01:34.046 --> 00:01:36.592 so youandnbsp;might just call this one good to go. 00:01:36.592 --> 00:01:43.074 But even with clear rotor rub, we should at least be aware of other thingsandnbsp;that can cause or amplify this symptom. 00:01:43.074 --> 00:01:45.194 Wheel allignment is critical toandnbsp;check. 00:01:45.194 --> 00:01:49.736 Especially on open dropout bikes, fully seating the wheel can solve the problem 00:01:49.736 --> 00:01:52.663 and it can even work on thru-axle bikes. 00:01:53.873 --> 00:01:57.041 A bent rotor will show a lot ofandnbsp;movement side to side, 00:01:57.041 --> 00:01:59.734 and this makes pad alignment difficult or impossible. 00:01:59.734 --> 00:02:03.602 Rotor replacement is a good option, but some rotor truing may be possible, 00:02:03.602 --> 00:02:06.027 andandnbsp;that process is shown in this other video. 00:02:06.027 --> 00:02:08.165 You should also check the rotor for play. 00:02:08.165 --> 00:02:13.280 Rotors are secured using either mounting bolts, or a lockring. 00:02:13.280 --> 00:02:16.093 See this otherandnbsp;video for rotor installation. 00:02:21.000 --> 00:02:26.790 Bearing play at the hub is also easy to check for. Just rock the wheel back and forthandnbsp;as shown. 00:02:26.790 --> 00:02:29.080 If there's play, fix it. 00:02:35.468 --> 00:02:41.230 Another issue is when dust and dirt collectsandnbsp; on one or both of the pistons and causes themandnbsp;to stick. 00:02:41.230 --> 00:02:44.841 In many cases, you can still achieveandnbsp; proper alignment with sticky pistons, 00:02:44.841 --> 00:02:47.571 but for more information see this other video. 00:02:47.571 --> 00:02:53.127 That's finally it for diagnosis. Let's get into the alignment procedure. 00:02:56.801 --> 00:03:00.096 Aligment procedures are theandnbsp;same for front and rear brakes. 00:03:00.096 --> 00:03:04.840 Loosen the mounting bolts until the caliperandnbsp;body is able to freely move side to side. 00:03:06.460 --> 00:03:10.013 Note that on some bikes, the mountingandnbsp;bolts are under the stay 00:03:10.013 --> 00:03:11.668 or on a bracket. 00:03:11.668 --> 00:03:13.808 Now we squeeze the brake lever. 00:03:14.234 --> 00:03:16.762 This centers the caliper body over the rotor. 00:03:16.762 --> 00:03:19.750 While holding the lever, snug up the bolts. 00:03:23.043 --> 00:03:25.209 Release the brake lever. 00:03:25.209 --> 00:03:29.608 Spin the wheel to test for pad rub. If there is no rubbing, the pads areandnbsp;aligned. 00:03:29.608 --> 00:03:35.125 Secure the mounting bolts to full torque — 6-8 Nm — and your work is complete.andnbsp; 00:03:35.125 --> 00:03:39.151 If the pads are still rubbing,andnbsp;we need to do some fine tuning. 00:03:39.151 --> 00:03:44.144 Loosen one bolt at a time, and adjust untilandnbsp; there is a gap on either side of the rotor. 00:03:44.144 --> 00:03:48.284 Take extra caution with your fingers andandnbsp; tools while working near a spinning wheel. 00:03:59.840 --> 00:04:06.937 Once the pads are not rubbing,andnbsp;fully secure each mounting bolt — typically 6-8Nm — and the process is complete. 00:04:10.626 --> 00:04:14.668 Some brakes have conical washers to assist in perpendicular alignment. 00:04:15.983 --> 00:04:22.819 Do not add washers ifandnbsp;none were designed to be there in the first place, as the pads will no longer align with the rotor. 00:04:22.819 --> 00:04:26.584 Conical washers can also be found between the bolt head and the caliper. 00:04:26.584 --> 00:04:29.963 These washersandnbsp;allow for proper bolt head alignment. 00:04:29.963 --> 00:04:34.562 If after trying all these procedures, and nothingandnbsp; seems to work for an adequate alignment, 00:04:34.562 --> 00:04:37.041 there maybe issues with yourandnbsp;caliper mounting system. 00:04:37.041 --> 00:04:41.322 It is assumed the frame mounts areandnbsp;correctly machined and square with the rotor. 00:04:41.322 --> 00:04:45.278 But if mounts are not square, bikeandnbsp;shops are able to face or machine the 00:04:45.278 --> 00:04:50.441 with the Park Tool DT-5.2 toandnbsp;improve alignment, as seen in this other video. 00:04:52.407 --> 00:04:54.990 Thanks for joining us onandnbsp;hydraulic disc brake alignment. 00:04:54.990 --> 00:04:59.565 If this video helped you out, please shareandnbsp;it with your friends, and subscribe to our channel. 00:04:59.565 --> 00:05:06.204 Sometimes all it takes is that one bit of knowledge to take your ride, your friends ride, or your customer's ride to the next level. 00:05:06.204 --> 00:05:07.807 Thanks for watching.