Hydraulic disc brake experience

[James]

The GLW has Shimano hydraulic disc brakes on her urban commuter/touring
bike.

Recently the front brake system degraded to the point that the lever
could easily be pulled all the way to the bars. Not good. I bought a
bleed kit and Shimano brake oil for $50. I bled both front and back
brakes as instructed by Shimano. The front brakes worked again as new.

The front brake started making horrid squealing noises. I'm not certain
if this started before or only after I bled the brakes.

However, I noticed the hose from the front brake caliper was damp with
oil near the lever. I suspect the hose connection to the lever has
leaked. Perhaps this is why the system needed bleeding in the first
place. I tried tightening the nut (that compresses an olive on to the
hose just inside the lever body). I'm not certain I have stopped the
leak though.

I suspect the oil moved down the outside of the hose and on to the disc
and pads, and that is what caused the horrid noise.


My cable actuated disc brakes on my gravel/touring bike are working fine
though.



--
JS

[slto...@gmail.com]

I used a flat bar and Avid brakes. They work well but are FAR too powerful for a gravel bike and I suggest that if you use these get the smallest diameter disk you can fit.

[jbeattie]

On Monday, April 8, 2019 at 5:33:27 PM UTC-7, James wrote:

Probably an accurate diagnosis. If in doubt, clip the end and put in a new barb and olive and reinstall. Also check the calipers to make sure there is no leak at the bleed port or the two halves of the body due to a bad inner seal. I had a leaking bleed port because the port grub screw was not seating due to gunk, probably from manufacturing since this was a new brake. I opened the brake and replaced the inner o-ring and worked with the port and screw -- and I think I got it fixed. And yes, a leak onto your pads will significantly degrade braking and cause your brakes to howl -- as will road crap. Bicycle plumbing! The good part is that a 105 or Ultegra level caliper is relatively cheap and plentiful.

-- Jay Beattie.

[John B.]

On Tue, 9 Apr 2019 10:33:21 +1000, James <james.e...@gmail.com>
wrote:

>The GLW has Shimano hydraulic disc brakes on her urban commuter/touring
>bike.
>
>Recently the front brake system degraded to the point that the lever
>could easily be pulled all the way to the bars. Not good. I bought a
>bleed kit and Shimano brake oil for $50. I bled both front and back
>brakes as instructed by Shimano. The front brakes worked again as new.

Just as a comment, you can buy mineral brake oil equal in viscosity to
Shimano's for considerable less money :-)

>The front brake started making horrid squealing noises. I'm not certain
>if this started before or only after I bled the brakes.
>
>However, I noticed the hose from the front brake caliper was damp with
>oil near the lever. I suspect the hose connection to the lever has
>leaked. Perhaps this is why the system needed bleeding in the first
>place. I tried tightening the nut (that compresses an olive on to the
>hose just inside the lever body). I'm not certain I have stopped the
>leak though.
>
>I suspect the oil moved down the outside of the hose and on to the disc
>and pads, and that is what caused the horrid noise.
>

Clean the discs and pads with something like alcohol, that leaves no
oily residue, and see if that helps temperately but if the pads are
oil soaked they will have to be replaced.

>
>My cable actuated disc brakes on my gravel/touring bike are working fine
>though.

Probably don't have to bleed them very often either :-)
--
cheers,

John B.

[James]

On 9/4/19 1:11 pm, John B. wrote:
> On Tue, 9 Apr 2019 10:33:21 +1000, James <james.e...@gmail.com>
> wrote:
>
>> The GLW has Shimano hydraulic disc brakes on her urban commuter/touring
>> bike.
>>
>> Recently the front brake system degraded to the point that the lever
>> could easily be pulled all the way to the bars. Not good. I bought a
>> bleed kit and Shimano brake oil for $50. I bled both front and back
>> brakes as instructed by Shimano. The front brakes worked again as new.
>
> Just as a comment, you can buy mineral brake oil equal in viscosity to
> Shimano's for considerable less money :-)

Thanks. I assumed so, but wanted the funnel, syringe and hose as well,
that all came as part of a bleed kit.

>
>> The front brake started making horrid squealing noises. I'm not certain
>> if this started before or only after I bled the brakes.
>>
>> However, I noticed the hose from the front brake caliper was damp with
>> oil near the lever. I suspect the hose connection to the lever has
>> leaked. Perhaps this is why the system needed bleeding in the first
>> place. I tried tightening the nut (that compresses an olive on to the
>> hose just inside the lever body). I'm not certain I have stopped the
>> leak though.
>>
>> I suspect the oil moved down the outside of the hose and on to the disc
>> and pads, and that is what caused the horrid noise.
>>
> Clean the discs and pads with something like alcohol, that leaves no
> oily residue, and see if that helps temperately but if the pads are
> oil soaked they will have to be replaced.

I used acetone.

>>
>> My cable actuated disc brakes on my gravel/touring bike are working fine
>> though.
>
> Probably don't have to bleed them very often either :-)

Indeed.

--
JS

[John B.]

On Tue, 9 Apr 2019 14:19:51 +1000, James <james.e...@gmail.com>
wrote:

>On 9/4/19 1:11 pm, John B. wrote:
>> On Tue, 9 Apr 2019 10:33:21 +1000, James <james.e...@gmail.com>
>> wrote:
>>
>>> The GLW has Shimano hydraulic disc brakes on her urban commuter/touring
>>> bike.
>>>
>>> Recently the front brake system degraded to the point that the lever
>>> could easily be pulled all the way to the bars. Not good. I bought a
>>> bleed kit and Shimano brake oil for $50. I bled both front and back
>>> brakes as instructed by Shimano. The front brakes worked again as new.
>>
>> Just as a comment, you can buy mineral brake oil equal in viscosity to
>> Shimano's for considerable less money :-)
>
>Thanks. I assumed so, but wanted the funnel, syringe and hose as well,
>that all came as part of a bleed kit.

Amazon sells a complete kit, funnel, hose, oil etc. for about A$ 22.40
(I'm assuming that the Ausi dollar is about par with the Singapore
dollar )

>>
>>> The front brake started making horrid squealing noises. I'm not certain
>>> if this started before or only after I bled the brakes.
>>>
>>> However, I noticed the hose from the front brake caliper was damp with
>>> oil near the lever. I suspect the hose connection to the lever has
>>> leaked. Perhaps this is why the system needed bleeding in the first
>>> place. I tried tightening the nut (that compresses an olive on to the
>>> hose just inside the lever body). I'm not certain I have stopped the
>>> leak though.
>>>
>>> I suspect the oil moved down the outside of the hose and on to the disc
>>> and pads, and that is what caused the horrid noise.
>>>
>> Clean the discs and pads with something like alcohol, that leaves no
>> oily residue, and see if that helps temperately but if the pads are
>> oil soaked they will have to be replaced.
>
>I used acetone.

That will work.

>>>
>>> My cable actuated disc brakes on my gravel/touring bike are working fine
>>> though.
>>
>> Probably don't have to bleed them very often either :-)
>
>Indeed.
--

cheers,

John B.

[James]

On 9/4/19 3:57 pm, John B. wrote:
> On Tue, 9 Apr 2019 14:19:51 +1000, James <james.e...@gmail.com>
> wrote:
>
>> On 9/4/19 1:11 pm, John B. wrote:
>>> On Tue, 9 Apr 2019 10:33:21 +1000, James <james.e...@gmail.com>
>>> wrote:
>>>
>>>> The GLW has Shimano hydraulic disc brakes on her urban commuter/touring
>>>> bike.
>>>>
>>>> Recently the front brake system degraded to the point that the lever
>>>> could easily be pulled all the way to the bars. Not good. I bought a
>>>> bleed kit and Shimano brake oil for $50. I bled both front and back
>>>> brakes as instructed by Shimano. The front brakes worked again as new.
>>>
>>> Just as a comment, you can buy mineral brake oil equal in viscosity to
>>> Shimano's for considerable less money :-)
>>
>> Thanks. I assumed so, but wanted the funnel, syringe and hose as well,
>> that all came as part of a bleed kit.
>
> Amazon sells a complete kit, funnel, hose, oil etc. for about A$ 22.40
> (I'm assuming that the Ausi dollar is about par with the Singapore
> dollar )
>

I looked at a number of sources. Many appear cheaper until you include
shipping. I bought one from an Australian supplier that guaranteed
delivery before the next weekend and was only a couple of $ more than
the cheapest equivalent I could find elsewhere.

--
JS

[Chalo]

A cable has never leaked out of one of my cable-actuated brakes, disc or no. A cable has never fouled any of my breaking surfaces by touching them, nor damaged the pads beyond repair.

These are a couple of things to bear in mind when you use oil instead of cable to apply the brake.

[John B.]

On Tue, 9 Apr 2019 16:33:05 +1000, James <james.e...@gmail.com>

Yes that is a real "gotcha". Yes Sir. We ship to Thailand. Then you
get the bill for shipping and customs and the price seems to have
doubled :-(
--
cheers,

John B.

[Frank Krygowski]

On Tuesday, April 9, 2019 at 3:09:56 AM UTC-4, Chalo wrote:
> A cable has never leaked out of one of my cable-actuated brakes, disc or no. A cable has never fouled any of my breaking surfaces by touching them, nor damaged the pads beyond repair.
>
> These are a couple of things to bear in mind when you use oil instead of cable to apply the brake.

+1

- Frank Krygowski

[jbeattie]

On Tuesday, April 9, 2019 at 12:09:56 AM UTC-7, Chalo wrote:
> A cable has never leaked out of one of my cable-actuated brakes, disc or no. A cable has never fouled any of my breaking surfaces by touching them, nor damaged the pads beyond repair.
>
> These are a couple of things to bear in mind when you use oil instead of cable to apply the brake.

Hydraulics are not all sunshine and roses, but long, enclosed cable runs and weak return springs on some mechanical discs like the BB7s, made for a draggy, poor performing rear brake. I changed cable and housing and even the mechanical caliper and could never get my rear to work that well. Running it half the year in rain probably didn't help either.

I much prefer the hydraulic rear brake on my commuter, and it has been problem free. The front brake is great, but so was the cable brake. The hydraulic pads self-adjust, which is a nice feature -- and there were times when I forgot to dial-in the pad on my cable front brake and had some scary moments on the sled-runs on my commute route. That was my own fault.

The only problem hydraulic brake I ever owned was a front brake that was bad out of the box. It spoiled some pads, but I resurrected those with brake cleaner and sanding.

-- Jay Beattie.

[Ralph Barone]

I think that I once had a brake cable "leak" out of the housing, resulting
in a loss of braking capability.

[AMuzi]

On 4/9/2019 9:25 AM, Ralph Barone wrote:
> Frank Krygowski <frkr...@gmail.com> wrote:
>> On Tuesday, April 9, 2019 at 3:09:56 AM UTC-4, Chalo wrote:
>>> A cable has never leaked out of one of my cable-actuated brakes, disc or
>>> no. A cable has never fouled any of my breaking surfaces by touching
>>> them, nor damaged the pads beyond repair.
>>>
>>> These are a couple of things to bear in mind when you use oil instead of
>>> cable to apply the brake.
>>
>> +1

> I think that I once had a brake cable "leak" out of the housing, resulting
> in a loss of braking capability.

If it's British built his might help:
http://www3.telus.net/bc_triumph_registry/smoke.htm


--
Andrew Muzi
<www.yellowjersey.org/>
Open every day since 1 April, 1971

[Frank Krygowski]

On Tuesday, April 9, 2019 at 10:05:07 AM UTC-4, jbeattie wrote:

> The hydraulic pads self-adjust, which is a nice feature -- and there were times when I forgot to dial-in the pad on my cable front brake and had some scary moments on the sled-runs on my commute route. That was my own fault.

Since I've done only short rides, not any great distances on a disc brake bike
(cable or hydraulic): How often do you have to "dial-in" your cable disc
brakes?

- Frank Krygowski

[jbeattie]

For me, after I ran out of lever travel and didn't stop. I let it get sloppy, and it went from bad to worse during a rainy ride down some very steep hills.

I usually adjusted every month or less to keep the brakes firm. I don't know what is recommended, and that undoubtedly varies based on individual use, weather and pad type. You hear stories about DH riders blowing through pads in a day or two, although those are hydraulic pads that self adjust. I knew my BB7 pads were shot when I got that pinging sound of the return spring hitting the rotor. Ooops.

That, BTW, is another issue with hydraulics. You have to police hydraulic pads because they will keep adjusting until you're braking with the aluminum carriers. When you adjust the pads manually on cable discs, at least you have a reminder to look at the pads -- whether you decide to look is up to you. Hydraulic pads are supposed to be replaced at .5mm, and I just measure them in place with a feeler gauge but you can take them out and do it with a micrometer. That is now an additional maintenance requirement and part of the care and feeding of discs.

-- Jay Beattie.

[David Scheidt]

Frank Krygowski <frkr...@gmail.com> wrote:

Depends on pad wear. When I had a mechanical caliper on the front
wheel of my commuter, I'd have to adjust five or six times per set of
pads. (and probably should have done so a bit more.) In winter,
riding in Chicago's lovely slush and grit, that was every couple
weeks. In the summer, a lot less. I put a lot more miles on in the
summer over winter, too. Mountain bikers in nasty gritty mud can ruin
a set of pads on a single ride, and have to adjust their brakes on the
trail; other places, where the mud is slipperier and not as gritty,
they'll last months.

--
sig 9

[Chalo]

My first set of modern IS conforming disc brakes (Hayes MX1) burned the pads all the way to their backings in less than 20 miles of central Seattle city riding. The fully metallic EBC replacement pads lasted for more than 10 years (though the bike was not my primary ride for the entirety of that time).

I guess this is to say there may be some variation in wear rate.

[slto...@gmail.com]

On Wednesday, April 10, 2019 at 12:35:39 AM UTC-7, Chalo wrote:
> My first set of modern IS conforming disc brakes (Hayes MX1) burned the pads all the way to their backings in less than 20 miles of central Seattle city riding. The fully metallic EBC replacement pads lasted for more than 10 years (though the bike was not my primary ride for the entirety of that time).
>
> I guess this is to say there may be some variation in wear rate.

I was riding my CX bike off-road and burned a set of disk pads in perhaps 100 miles or less. I also burned a front disk into a grooved blackened thing. I replaced the steel plate with AL and was more careful and everything seems to work well. But then I am not riding anywhere near as hard as I was.

Yesterday I did the first Moraga Ride since October! Door to door for my part is 37 miles and 3,300 feet of climbing. I was pretty damn slow and the Tierra Bella metric I'm riding is Saturday. I hope to be able to complete it if I ride carefully. The last time I rode it I made the mistake of riding the final 5 miles at 28 mph. That put me into almost a haze. I couldn't even find my car in the lot.

[jbeattie]

FWIW, I have a Tierra Bella patch (remember patches?) from 1979 or '80 designed by Leigh High art teacher and cyclist Ken Schwab. I think Ken did that one. I use it as a coaster. That was a fun ride. I remember one year when they closed the course mid-ride because of a giant storm -- or if it wasn't officially closed, everyone bailed. Back in the day, you went of Hecker Pass, IIRC, but no longer. It looks like a series of loops now, which makes it easier for the organizer.

-- Jay Beattie.

[Radey Shouman]

Car disk brake pads generally have a little metal tab that extends
towards the disk to the wear limit of the pad. Its purpose is just to
squeal painfully *before* the pad is actually worn through. I'm not
sure of any reason this couldn't work for bicycles.

[dave]

On Tue, 09 Apr 2019 09:35:06 -0500, AMuzi wrote:

> On 4/9/2019 9:25 AM, Ralph Barone wrote:
>> Frank Krygowski <frkr...@gmail.com> wrote:
>>> On Tuesday, April 9, 2019 at 3:09:56 AM UTC-4, Chalo wrote:
>>>> A cable has never leaked out of one of my cable-actuated brakes, disc
>>>> or no. A cable has never fouled any of my breaking surfaces by
>>>> touching them, nor damaged the pads beyond repair.
>>>>
>>>> These are a couple of things to bear in mind when you use oil instead
>>>> of cable to apply the brake.
>>>
>>> +1
>
>
>> I think that I once had a brake cable "leak" out of the housing,
>> resulting in a loss of braking capability.
>
>
> If it's British built his might help:
> http://www3.telus.net/bc_triumph_registry/smoke.htm

Awesome. :) I could have done with some of that when I had a mini.

--
davethedave

[Andre Jute]

On Tuesday, April 9, 2019 at 8:09:56 AM UTC+1, Chalo wrote:
> A cable has never leaked out of one of my cable-actuated brakes, disc or no. A cable has never fouled any of my breaking surfaces by touching them, nor damaged the pads beyond repair.
>
> These are a couple of things to bear in mind when you use oil instead of cable to apply the brake.

At the very least it is smart to consider a sealed-for-life system if you must have hydraulic liquid on on your bike. I specced one on my fave bike because I was fed-up with uncontrollably sudden stops from Shimano's hub brakes, instantaneous pad wear from Shimano's disc brakes, and the constant adjustments required by mechanical rim brakes. All I wanted was a progressive, strong enough, and service-free system, not too much to ask if you're waving a fistful of money. Bike vendors, importers and manufacturers, all except one, looked at me like I was crazy: didn't I know that a cyclist proves his worth by suffering?

With Magura's sealed for life system, the HS11 and HS33, I got 622mm discs because the hydraulic callipers work on the rim of the wheel, not inefficiently near its centre. Avoiding the pisspoor advice on this forum that only the strongest brakes would prove my manhood, I specified the lower pressure, much more progressive HS11*, and even removed the cross-fork stiffening back between the callipers for a bit of additional slack, and have been very happy with the resulting smoothly progressive braking for 10 years. Zero service in ten years, not even changing the brake blocks, which still have another 10K left in them, having already done 10K and change. I still have all the replacement parts (brake blocks, retubing kit, etc) that I ordered with the bike, and don't foresee using them either.

* Back then the -33 had a smaller chamber than the -11, and thus more pressure. Today both are mechanically and hydraulically exactly the same, the only difference the last time I looked being that the -33 and "racing" derivatives are dressed up in sober black to look "professional" and bump up the price while the -11 offers colourful slipcovers, which someone will no doubt shortly be along to damn as "girly" and far too cheerful for "real cyclists".

Andre Jute
Hedonist

[slto...@gmail.com]

The problem with the Century is that you get about 40 miles into the ride on the flats and then come to the base of a 10 mile hill that climbs a thousand feet. At the top is a state park and lunch. So no one does it after they've done it once. Then a 5 mile ride across the flats and past the IBM R&D center and another 20 miles through the hills and then down onto the flats and a ride with a tailwind back to the college. I always wanted to work at IBM R&D but you had to have a degree. I can see the value of a degree but I also know that most of the R&D doesn't require high end calculus and they were silly to limit themselves to people who especially these days have imaginations more attuned to Marvel Comics. I did not come up with ideas - I figured out how to turn them into reality.

[slto...@gmail.com]

Well, you can actually see the brake pad on a bike.

[David Scheidt]

Chalo <chalo....@gmail.com> wrote:
:A cable has never leaked out of one of my cable-actuated brakes, disc or no. A cable has never fouled any of my breaking surfaces by touching them, nor damaged the pads beyond repair.

:These are a couple of things to bear in mind when you use oil instead of cable to apply the brake.

I've never gotten a puncture wound from a hyraulic brake hose, let
alone one that required (very very minor) surgery. Can't say that
aobut cable operated brake cables.

--
sig 125