I’ve stumbled upon an issue. Since I am really bad with fixing, building etcetera a friend helped me with changing my stem and handlebars into a full integrated one-piece handlebar. At the same time I changed the brake pads on both brakes, Ultegra hydraulic disc brakes. The front brake started to make awful noises and I assumed it was contaminated brake pads, even if they were brand new. I cleaned disc and brake pads with isopropyl alcohol and sandpaper, no improvement. The squeling and poor braking performance accured with different wheels and brake discs, so today I got a new set of brake pads. No change whatsoever
I’m starting to doubt that the brake got re-installed properly. I can also hear the cables rattle in the fram when turning the handlebars and maybe a slightly un-tighted headset, which I tigtened since.
Is there a simple explanation to this? I know how to align/center the brake and disc but that’s about it when it comes to my disc brake mechanical skills.
Did you (or your friend) bleed the brakes, after changing handlebars? How does the brake lever feel, spongy or like there’s no resistance? There could be air in the system, which can both stop the caliper pistons from moving out and moving back properly.
I’d take it to a shop if I was you, easiest way to get it sorted.
Definitely sounds like your pads are getting contaminated. I’d probably just have a shop take a look and probably pass on that friend doing work on your bike in the future lol.
Probably not. Any explanation is a guess. You will have to go from one end to the other of the system to figure it out. Like posted above “a trip to your LBS “ is the easiest way at this point.
Never spray anything on the pads. Only use IPA on the discs. If you’re handy enough and have the means, get a propane torch, hold the pads with a pliers, and torch the pads until they stop smoking, then 30 seconds longer. Be extremely careful because the pads will burn you and anything they touch. Put them on a concrete surface out of view or piece of wood to cool. Then put them back in and bed them in.
Yes he did. We needed to replace the brake hose because it was to short, more or less new installment of the front brake. The rear brake hose was long enough for the new cockpit. But if I remember correctly, he bled that one too since it was a while ago since I had it done.
Can’t see any.
I’ve had hydraulic discs for a year and half now, using them in awful conditions, cleaning the bike with degrease and such and never had any problems with the brakes. I put on brand new brake pads and the squealing begun. I thought I contaminated them before removing replacement so I cleaned them and the disc. Not better. Tried another disc, same shit. Changed the pads to another brand new set - exactly the same result. I’m definitely going to take it to a shop but I’m very Y curious to know what could be the problem if not contamination.
And yeah, will go to the bike shop with issues I can’t handle myself in future .
I used set 1 for a week, sucked. Cleaned and sandpapered pads and disc - nothing. Changed the pads - nothing. The rear brake got new pads as well without issues.
After further inspection I can tell the front brake pistons are leaking brake fluid. The pads are moist on the backside so to speak.
A quick Google tells me the brake caliper got damaged, probably when my pal pushed the pistons back.
Is this a cause for squealing? Could this be the cause for 0 to none brake power?
Yes to both. The oil contaminates the brake pads - even if you don’t see it on the pads themselves, it only needs a little bit and the oil will fimd it’s way around to the pad site.
And yes, low power both because the pads don’t work right, but also because the hydraulic pressure is not there. When you squeeze the brake lever to increase the pressure, the oil just leaks out.
Are you certain the pads weren’t contaminated with fluid during the repair? Did you replace the olive? Is the hose / olive nut tight? Be sure to pull the pads out and clean the entire caliper and piston seal area very well, use isopropyl alcohol (ipa) and clean rags. Really clean! To the point that a paper towel won’t show any residue. Insert a brake bleed block between the pistons and squeeze, repeat, check for new fluid leaking. It may be that this is beyond your experience level and a shop may be the best solution.
Weird question, perhaps: Did they use mineral oil or brake fluid? Standard car brake fluid is caustic and would likely eat seals meant for mineral oil. Just asking because I’ve heard of a few using the wrong fluid before.
On the heating of the pads, the LBS laughed at that idea and said it was totally not necessary to ‘cook’ brake pads. They claimed it can cause the pad to delaminate from the brake backing block. I used to sand pads, but it’s really easy to get them off angle, even with really fine sandpaper. I’m taking a more hands off to ‘fixing’ breaks that can make the problem go away, but introduce other self-induced problems.
I have had better luck with a brass wire drill brush for the rotors. I don’t hold the brush in any single spot, letting the brush turn the wheel as it works. Proof that almost anything can be used and anyone can find ‘proof’ that something works. I tried the Squeal Out, didn’t work for me. ISO does help sometimes. My Ultegra’s squeal right now, but not very much. I’ll just live with it until it gets worse.
Two different sets of brand new pads. The pistons are leaking so I guess everything clean you put in the brake will be contaminated. Like the black death of rotors and pads.
I’d recommend cleaning the caliper & pistons really well with alcohol and then doing some testing to see if the pistons regularly leak, or if some oil got through/on them randomly. If they are regularly leaking, then you need a new caliper, but I have seen calipers weep oil around the pistons occasionally and perform fine afterward.
The bottom line in my opinion as someone who’s replaced thousands (?) of hydraulic brake pads and rotors is that once a contaminated pad has been used on a rotor, that rotor is junk. I’ve tried everything in the book, and while some might claim to have fixed a squealing pad/rotor, there isn’t anything that is going to consistently work.
I’d save yourself the time and money of replacing multiple sets of pads and start fresh with new pads and rotors once you’ve diagnosed the caliper issue.
I could see marks from the pistons on the first set of brake pads, and the new set was really wet so that they are leaking is no doubt.
I ordered a new caliper today.
Looks like one broken caliper, three different rotors and two sets of brake pads. Good thing I have a “stupidity insurance”
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