I'm an Idiot! (Soft Spongy Brakes)


Comments • 2 530

  • Junk Name
    Junk Name  3 days back

    the previous owner might have put on the old rotor.

    • Miguel Angel Cotto Morales

      Awesome storytelling!

      • ApprenticeGM
        ApprenticeGM  6 days back

        I love how you trouble shoot! It's exactly like except for one small exception . . . I rarely get to the end (the rotor) lol. Thanks for sharing!

        • Esteban Gonzalez
          Esteban Gonzalez  1 weeks back

          Hi from Costa Rica, love your videos 👌🏻👌🏻

          • Petey Bones
            Petey Bones  1 weeks back

            14:46 Indeed, including the old grey matter.

            "Of all the things I've lost, I miss my mind the most"🤯 -Mark Twain

            • Chris Peoples
              Chris Peoples  1 weeks back

              HI Tony, I, like you, am an idiot, I only improve upon your level of being idiotic by being a high school physics teacher! Well, today was the day I taught Pascal's Principle and the concept of a hydraulic lever to my AP Physics 2 students as a part of their fluid mechanics unit (it's not required by nor apart of the AP Physics 2 curriculum, but I teach it anyway). You video was very much loved by my students and they now know why I can be so strange at times (maybe my bad habit of mistaking the cutting oil cup for my coffee cup in the morning (both taste about the same anyway...). You now have 14 new fans besides me.

              Thanks again for the great work for solving a problem and demonstrating important physics concept,

              Chris Peoples
              Physics Teacher
              Sunny Hills High School, Fullerton, California

            • Clint The Great
              Clint The Great  2 weeks back

              For over thirty years, KLR owners (me being one of them) have suffered with soft and spongy brakes. After watching this video, guess what . . . nothing changed. Search the forums and you’ll see that, even after replacing/rebuilding every part of the brake system, including new rotor, you still have soft and spongy brakes. Many have fixed the problem by swapping in a four piston caliber from a different bike. Point being, sometimes the engineers screw it up and despite knowing of the problem, the manufacturer never fixes the problem.

              Enjoyable video, sub’d and liked.

              • Baobab
                Baobab  2 weeks back

                Reminds me of the "pulsing" new (from ebay...Argentina?) DR650 rotor I bought. Different thicknesses... doh!

                • how bow dat
                  how bow dat  2 weeks back

                  dayum, using a syringe to bleed the brakes, never thought of that idea! thanks

                  • dandexinventor
                    dandexinventor  2 weeks back

                    my brakes squeal like a pig. I have tried everything, new pads, surfacing rotor, cleaning them both, tightening all the fasteners involved, but always, within a couple miles of riding, they begin squealing...? Oh, and it's a mountain bike with hydraulic brakes. My only guess, is dust. Is there a pad out there which dies not react to dust?

                    • cal c
                      cal c  3 weeks back

                      Machine a extended piston rod and swap out the old one from the caliper.

                      • Fabron Fretwell
                        Fabron Fretwell  3 weeks back

                        At the end, I thought you were gonna say, "keep your rotor in a vise."

                        • mangamaniaciam
                          mangamaniaciam  3 weeks back

                          Fun fact: My mountain bike has disc brakes. I replace the rotors more often than the braking pads themselves!!😳

                          • Ashton Gilmore
                            Ashton Gilmore  3 weeks back

                            I always use "subscribe oil".

                            • Eldon Triggs
                              Eldon Triggs  4 weeks back

                              Will ya look at that brass oil fill screw!

                              • MrMats0n
                                MrMats0n  4 weeks back

                                Awesome entertainment again. Just to point out, many smaller bikes at least have only one piston in the rear caliper pushing against a stationary brake pad. Also a worn rotor rarely manifests as spongey brakes because the brake system compensates for brake pad (and rotor) wear by pumping in more fluid into the lines from the reservoir.

                                • chris c
                                  chris c  4 weeks back

                                  I had the same problem in a car..turns out a caliper was the problem. The piston would suck in after you let off the brake so there was to much travel in the system.

                                  • Lazer
                                    Lazer  4 weeks back

                                    this guy is too funny... Love these videos

                                    • nigelft
                                      nigelft  1 months back

                                      Serious question from a guy whom did 'Shop' back in 1988/89 ...

                                      Is resurfaceing a rotor a thing ... and why ...? I mean, if you smart enough to skim off, say, 0.25mm*, you ought to be smart enough not to do somthing like that ...

                                      [*= disclaimer before I get yelled at ...

                                      Although I did both metal and woodwork as a kid, most of my adult life was spent staring down the eyepiece of a microscope at wee timourus beasties (aka bacteria), so in my head:

                                      > 0.25'' = thinks in imperial
                                      < 0.25'' = thinks in metric

                                      Unfortunately, that is the limit of my brain to resolve distances, but hey ... don't judge ...

                                      And don't even get me started on Ångstroms ...]

                                      • daft nord
                                        daft nord  1 months back

                                        thanks for this public service announcement

                                        • Ken Walter
                                          Ken Walter  1 months back

                                          Tony I love your videos but we have to agree to disagree on this one. If you have a rotor slightly under spec with brand new pads, wouldn’t the caliper pistons be in the same position they would be in with a new rotor and slightly worn pads??

                                          You can run the pads down to nothing and still have good stopping. The system is designed to have the same master cylinder travel no matter where the caliper pistons are. That’s why there is a reservoir.

                                          Glad you fixed it and you needed a rotor anyway, but that’s not what fixed it.

                                          • Pippo Lacoste
                                            Pippo Lacoste  1 months back

                                            I share your same thought. Pads wear much more than rotors and they still bite.

                                        • Levisgil47
                                          Levisgil47  1 months back

                                          Could have been the same problem as yours but for me it turns out I have done about the same work figuring out at last it was a miss mount of the caliper shaft clips that gave me a weak break! Though still having problems with loosing brakes after a long run downhill...
                                          Sharing the same passion except I got a Beta and 4 strokes further more. The main difference with your french lady could be the frame that is made of aluminium and probably more difficult to weld for some repairs...and It's italien :) but I'm french. Noh!

                                          • Ted Timmons
                                            Ted Timmons  1 months back

                                            and here I thought it was incompatible DOT3 vs DOT4 fluid.

                                            • Absolute Nonsense
                                              Absolute Nonsense  1 months back

                                              10.40 i was pretty sure he was goin to say " you can also take this bike to the outer space where no gravity exist "

                                              • easyascherrypie
                                                easyascherrypie  1 months back

                                                Holy shit, this sounds exactly like the issue I’m having with my Ford Escape. I’ve checked lines, replaced the master, bled and bled until I felt lightheaded and woozy, but haven’t checked my rotors. Sure as shit they’re worn and warped. If this fixes it, I’ll be a happy man!

                                                • RB
                                                  RB  1 months back

                                                  cool stuff

                                                  • Tom Grant
                                                    Tom Grant  1 months back

                                                    It was probably that the old rotor was oil impregnated and therefore not gripping. The brakes aren't really spongy but they feel that way because they don't work and you keep pressing harder for no effect. In my experience, some bicycle rotors do this - where no amount of cleaning or resurfacing will get rid of the oil, whereas other brands can be easily fixed by degreasing and maybe sanding them down a bit.

                                                    • Riley Bush
                                                      Riley Bush  1 months back

                                                      That's strange. I run my rotors really thin and i've never had that problem. The pistons migrate outward to take up the slack as the pads wear, that's why you need to push them in again when you replace parts. when pushed to the extreme, the pistons will run out of travel and pop out of the caliper. That's an extreme case, but it means that there's no internal limiter that would cause the symptoms that you describe in the video.
                                                      I'm really glad you got your brake working well again, but i'm still confused. maybe the issue is with the piston seals in the caliper not allowing the brake pistons to migrate out and take up the slack. If that's the case, I imagine your soft brake will return when the pads wear by .035" and introduce the same gap into the system.
                                                      I've also had brakes feel soft when pads and rotors are contaminated. That could be another reason that replacing the rotor did the trick. Thanks for posting!

                                                      • Andy Wyatt
                                                        Andy Wyatt  2 months back

                                                        could it be the master cylinder piston is now in a less worn area of the master cylinder after the rotor change

                                                        • Ian Vicedomini
                                                          Ian Vicedomini  2 months back

                                                          I guess it's not the first thing anyone looks at because let's face it, there are those who assume, oh it'll last forever. You're no idiot mate, when it gets to braking point, you won't stop until you've rectified the issue lol great video bud

                                                          • Bora Yurtoren
                                                            Bora Yurtoren  2 months back

                                                            Also, slightly bent rotors tend to "slap" the pads and make them move much further away than needed. This will make your brakes spongy, less reactive, or weak too.

                                                            • Svein Nygård
                                                              Svein Nygård  2 months back

                                                              findly you got it.. tak a brake, drink coffee and then "check your rotors..!"

                                                              • Church Watkins IV
                                                                Church Watkins IV  2 months back

                                                                .............wish i could clean my harley like that

                                                                • noredbull1
                                                                  noredbull1  2 months back

                                                                  I hope this channel is under Unesco protection

                                                                  • LTVoyager
                                                                    LTVoyager  2 months back

                                                                    That’s your problem. You put oil in your brake system. 😂

                                                                    • Rob M
                                                                      Rob M  2 months back

                                                                      It is probly just air stuck in the line, you should try to rebleed.

                                                                      • Mike Bidus
                                                                        Mike Bidus  2 months back

                                                                        Well I guess I never forget this lesson after all that . Thanks!

                                                                        • Painmaker
                                                                          Painmaker  2 months back

                                                                          16 minute watch for 1 minute of actual content. Somehow I was entertained throughout it all.

                                                                          • darrell griffiths
                                                                            darrell griffiths  2 months back

                                                                            If you had enough pad left, then the disc thickness was not your problem. The brake piston seals flex back into shape to release the force after applying the brake force. From what your saying if the pads are anything less than 75% your brakes are spongy, not so. Sorry but what your saying goes against all disc and caliper self adjusting design theory. Your pistons only return the the distance of the reflex of the square section of the piston seals, thats why they are square section. With your theory as soon as new pads are worn from new by 0.9mm the brakes will then become spongy, not so. The only way a thin disc can immitate a spongy brake is when the thickness is not enough to dissipate the generated heat when in hard use, causing heat induced brake fade, but this is not the same as a spongy brake. Like the humour in your vids, nice channel, keep up the good work man.

                                                                            • name name
                                                                              name name  2 months back

                                                                              The moral of the story is while cutting a brake line was funny, thinning a rotor is hilarious.

                                                                              • Simon Van City
                                                                                Simon Van City  2 months back

                                                                                The good news is an actual idiot would still be stumped. If it was easy, anybody could do it.

                                                                                • Felix le Fix
                                                                                  Felix le Fix  2 months back

                                                                                  man from the start of the video I was sure it was oil on the rotor/pad

                                                                                  • MasterThief117
                                                                                    MasterThief117  2 months back

                                                                                    I've been drinking brake fluid for years. Some people told me I'm addicted...but I swear I'm not...I can stop any time!

                                                                                    • I reckon I can build that

                                                                                      I can't help but think it was something else, because your brake pads have more than 2mm of wearable surface so new pads+worn rotor adds up to less caliper travel than worn pads+new rotor.

                                                                                      • Gurjeet Singh
                                                                                        Gurjeet Singh  2 months back

                                                                                        ok lets relate to me. happened to me once when i tore open a rc controller thinking its not turning on. checked all circuit. battery all caps. even was about to replace a capacitor. stupid me was pressing wrong button to turn it on and expecting ( led light was not turning on) later realized that led was (inbuilt) ON button itself. lol

                                                                                        • Stephan C
                                                                                          Stephan C  2 months back

                                                                                          Very good!

                                                                                          • Mick Peart
                                                                                            Mick Peart  2 months back

                                                                                            So, Tony, when your pads wear down .035" you will be back to the same point?? You could check the length of the push-rod in the M.cylinder. A shortened push-rod in car brakes once took some time to trace. Has the actual brake lever been replaced with incorrect, or deformed? While you have narrowed the problem down to lack of travel, I'm not convinced it was the disc. Apologies for the negativity.

                                                                                            • Derrie Symes
                                                                                              Derrie Symes  2 months back

                                                                                              I just had the exact same problem at the weekend on my pitbike. Thanks I now know the problem after a new master cylinder and pads