Brake Bleeding Advice

[98gtw]

It's time I tackled the brakes on the Screamer, what with warm weather just around the
corner (maybe).

The actuation point for the front brake (Magura hydraulic rim brake, model HS 11, I think) has
always been a little close the the handgrip. Brakes have been sufficiently grippy, though, so I've
let them be.

I'd like to get them balanced up with the rear so I'm looking for tips and techinques for filling
and bleeding. I've got the manual from Magura's site and its procedure looks pretty
straight-forward. At the moment the bike is suspended upside-down at a level that would be easy to
work at. Any reason I can't do the whole procedure inverted? Or is that really dumb?

Your experience is appreciated.

--
Dave 98GTW [email protected] (remove nospam to reply directly) Presto, Presto II, Screamer

 

[Dave Larrington]

Dave wrote:

> I'm looking for tips and techniques for filling and bleeding [Magura HS-11's].

Tip #1: Get a Magura service kit if you haven't already got one. Expensive but it's difficult to
proceed without one. Tip #2: Get one of the screw-in fittings from the service kit and bang it into
the end of the hose attached to the syringe. Actually, I see they now recommend this - they didn't
when I first started using Maggies, though. Tip #3: Be *very* careful when undoing the bolts. 99% of
brake fittings the world over are made of cheese.

HTH

Dave Larrington - http://legslarry.crosswinds.net/
===========================================================
Editor - British Human Power Club Newsletter
http://www.bhpc.org.uk/
===========================================================

 

[Earl The Bent B]

Dave: when you bleed each brake be sure to push the fluild from the caliper to the lever and as you
are doing this when all of the old fluid is gone keep pressure on the syringe while you tighten up
the bleeder valve on the lever. doing this will give maximum braking at all times. Thank you Earl
GRR,RANS V2 Ti-Rush

 

[Rorschandt]

"Dave Larrington" <[email protected]> wrote in news:[email protected]:

> Dave wrote:
>

> Maggies, though. Tip #3: Be *very* careful when undoing the bolts. 99% of brake fittings the world
> over are made of cheese.
>

You really have a low opinion of *cheese*, don't you?

rorschandt

 

[Dave Larrington]

Rorschandt wrote:

> You really have a low opinion of *cheese*, don't you?

I like cheese fine in its proper place, such as atop a pizza. As a material for the manufacture of
bolts, though, it leaves much to be desired...

Dave Larrington - http://legslarry.crosswinds.net/
===========================================================
Editor - British Human Power Club Newsletter
http://www.bhpc.org.uk/
===========================================================

 

[98gtw]

From Machinery's Handbook

" British Unified Machine Screws and Nuts.—British Standard B.S. 1981:1953 covers certain types of
machine screws and machine screw nuts for which agreement has been reached with the United States
and Canada as to general dimensions for interchangeability. These types are: countersunk,
raised-countersunk, pan, and

raised-cheese head screws with slotted or recessed heads;

small hexagon head screws; and precision and pressed nuts. All have Unified threads. Head shapes are
shown on page 1595 and dimensions are given on page 1597.

" Dave should know his cheese (head)

rorschandt <[email protected]> wrote in
news:[email protected]:

> "Dave Larrington" <[email protected]> wrote in news:[email protected]:
>
>> Dave wrote:
>>
>
>> Maggies, though. Tip #3: Be *very* careful when undoing the bolts. 99% of brake fittings the
>> world over are made of cheese.
>>
>
> You really have a low opinion of *cheese*, don't you?
>
> rorschandt
>

--
Dave 98GTW [email protected] (remove nospam to reply directly) Presto, Presto II, Screamer

 

[Ian D]

I'd say don't bleed them unless they've undergone some sort of leakage mishap. It's a sealed system
and shouldn't need it. The only time I've done mine is after installing when the cable is cut and
after a hose failure on a really old set. Those had never been bled in 10 years. A great product.
Just tweak the screw so that the pads are <1mm from the rim and you have all the stopping power you
could possibly need for a tiny movement of the lever.

...and a tip - if you really must take them to bits:

You do need a service kit - it contains new O rings you'll need if you don't want to create a new
leaky system. Note your tubes will be about 10mm shorter as a result of cutting off the old O rings
(another reason to leave them alone) In the kit you get 50ml of Magura oil. Go to your local Citroen
dealer and you can get 2L of the same stuff (Citroen hydraulic *mineral* oil for suspensions. Called
LHM Plus in the UK) for small money.

A $10 value for a $2 price as I believe you american chaps say with your colourful argot

Ian

 

[Ian D]

Note your tubes will be about 10mm shorter as a result of cutting off the old O rings

Only true if you undo the hose connectors, so don't and ignore that.

I am a chump - I do like cheese though

Ian

 

[Rorschandt]

"Ian D" <[email protected]> wrote in news:[email protected]:

> Note your tubes will be about 10mm shorter as a result of cutting off the old O rings
>
> Only true if you undo the hose connectors, so don't and ignore that.
>
> I am a chump - I do like cheese though
>
> Ian
>
>
>
>

I mentioned the entire "cheese and Dave Larrington" thingy because of historical notes made
previously by Mr. Larrington:

>
> <ob_recumbent>
> 1. The CX Safari would have been the finest HPV transporter in the
history
> of all things ever had they chosen not to have the blocks of the 2.5
litre
> turbodiesel made on the cheap, in India, out of cheese. In an ideal
world,
> I'd have one of these for carting bikes around:
> http://legslarry.crosswinds.net/images/large/CX.jpg

and further snippets:

> We have a different system, especially in the umpteen places where
they're
> replacing the traffic lights and perforce digging trenches right across
the
> road:
>
> 1. Dig trench, install cable, refill trench to old level
> 2. Wait a few days. Because repair detailed in (1) above has been carried out using cheese,
> passage of several hundred buses has chewed large hole in previously-repaired section.
> 3. Fill hole back to old level, as per (1).
> 4. Repeat repairs with cheese for ~18 months before approval is finally gained to use something
> more permanent.

and another:

> I use the nylon ones described on
> http://www.wisil.recumbents.com/wisil/wheeldisk/wheeldisk.htm (as one
might
> expect . I'm not currently using them on the road, as:
>
> a. I needed a new back wheel on the Speedmachine, which
> b. Required the removal of the brake disc, which
> c. Turned out to be a pain in the ar5e, as
> d. Hope make their fastening bolts out of cheese[1].

Not a criticism, just an observation.

rorschandt i like some cheese.

 

[Dave Larrington]

Ian D wrote:

> Go to your local Citroen dealer and you can get 2L of the same stuff (Citroen hydraulic *mineral*
> oil for suspensions. Called LHM Plus in the UK) for small money

Though if the gentleman is anywhere other than Europe, the chance of his having a local Citroen
dealer are low to negative...

I still have enough LHM left over from my Citroenthusiastic past to run Maguras into the
next century.

Dave Larrington - http://legslarry.crosswinds.net/
===========================================================
Editor - British Human Power Club Newsletter
http://www.bhpc.org.uk/
===========================================================

 

[Ian D]

Blimey - you're right - a country with no Citroens - how queer

From http://www.execulink.com/~dtierney/wmc/Magura/geninfo.htm - lots of Magura info for americans:

"Magura Oil, which is filled into the brakes in Germany is greenish - Shell Naturelle. Unfortunately
Shell USA doesn't sell (import) that same stuff. Shell USA says that this (environmental friendly)
oil is too expensive for the American market. Magura USA could get it in a special load (a boat
load?) but it probably would last to the year 3000.

Magura USA searched high and low and ended up with Finish Line Shock Oil No 5, which is actually a
mineral based synthetic oil and is of a reddish colour. Finish line shock oil is also environmental
friendly and if you can trust the folks at Shell, it will mix with the original Shell stuff. It also
has a better lubrication value than even the original German Shell. "

...too expensive - how depressing Finish line stuff is probably pretty costly too given it's niche.

Probably best to use cheese then

ian

 

[98gtw]

"Dave Larrington" <[email protected]> wrote in news:[email protected]: How
long should I have the bike upright before I bleed to give the air time to travel up to the brake
lever end of the system?

--
Dave 98GTW [email protected] (remove nospam to reply directly) Presto, Presto II, Screamer

> Dave wrote:
>
>> I'm looking for tips and techniques for filling and bleeding [Magura HS-11's].
>
> Tip #1: Get a Magura service kit if you haven't already got one. Expensive but it's difficult to
> proceed without one. Tip #2: Get one of the screw-in fittings from the service kit and bang it
> into the end of the hose attached to the syringe. Actually, I see they now recommend this - they
> didn't when I first started using Maggies, though. Tip #3: Be *very* careful when undoing the
> bolts. 99% of brake fittings the world over are made of cheese.
>
> HTH
>
> Dave Larrington - http://legslarry.crosswinds.net/
> ===========================================================
> Editor - British Human Power Club Newsletter
> http://www.bhpc.org.uk/
> ===========================================================
>

 

[Dave Larrington]

Dave asked:

> How long should I have the bike upright before I bleed to give the air time to travel up to the
> brake lever end of the system?

I should think a half-dozen quick squeezes of the lever would get the air up to the lever. You could
just drain the old fluid out into a handy container and re-use it, though.

Dave Larrington - http://legslarry.crosswinds.net/
===========================================================
Editor - British Human Power Club Newsletter
http://www.bhpc.org.uk/
===========================================================

 

[98gtw]

"Ian D" <[email protected]> wrote in news:[email protected]:

> I'd say don't bleed them unless they've undergone some sort of leakage mishap. It's a sealed
> system and shouldn't need it. The only time I've done mine is after installing when the cable is
> cut and after a hose failure on a really old set. Those had never been bled in 10 years. A

I think mine weren't set up well to begin with. Thel actuation has always been too close to the bar
for my taste. But I understand the "don't fix it if it ain't broke" philosophy.

--
Dave 98GTW [email protected] (remove nospam to reply directly) Presto, Presto II, Screamer

 

[Steve Baker]

[email protected] (Earl The Bent Brat) wrote in message
news:<[email protected]>...
> Dave: when you bleed each brake be sure to push the fluild from the caliper to the lever and as
> you are doing this when all of the old fluid is gone keep pressure on the syringe while you
> tighten up the bleeder valve on the lever. doing this will give maximum braking at all times.
> Thank you Earl GRR,RANS V2 Ti-Rush

It's not as important, seemingly, in the very small bike systems as it is in cars and motorcycles
but you will have better luck if you work with rather than against, nature. Air naturally rises in
hydraulic systems,as in a lot of other places. You should try first to follow Earl's very good
advice, and secondly, to do all this with the caliper lower than the master cylinder in the brake
lever complex. That will help to avoid having an air bubble hide in an obscure corner of the line,
waiting to turn your brakes to, you guessed it, cheese at a critical stop. An air bubble will
compress enough that it can't push the pad out toward the caliper. That's usually a bad thing. ->)

Steve Baker Speed Machine Windcheetah (the real speed machine)

 

[Torsten Lif]

OK, so this is a VERY late follow-up to this thread and I fully understand the issues some have with
re-beating dead horses, but...

IF you're hard-put to find suitable replacement oil for Magura hydraulics in the US, go to some
local BMW service shop and ask for their power-steering/brake-booster hydraulic oil. BMW and Audi
both use (at least in some models) a combined hydraulic system for brake- and steering servos. I
know this the hard way, from having owned an old Audi with leaking steering boosters. The "BMW" oil
I bought once was considerably thinner than the "Audi" grade I usually got, and the $20 quart ran
through the Audi's leaks in a week whereas the "Audi" stuff would last about a month. BUT, during
the brief period I had that "BMW" brand bottle of oil sitting in the trunk, waiting for when I'd
need to pour it in, I sheared a Magura line on the Linear and had to refill+bleed. Knowing how hard
it was to find Citroen stuff (I was living on Long Island, NY, at the time), I used some of the
"BMW" stuff and it's still in the Magura system today, 6+ years later.

OK, so maybe German stuff isn't much better than French in the US right now, but at least there are
a lot more BMW's than Citroens on the roads, so there should be shops.

/Torsten

Ian D wrote:
> Blimey - you're right - a country with no Citroens - how queer
>
> From http://www.execulink.com/~dtierney/wmc/Magura/geninfo.htm - lots of Magura info for
> americans:
>
> "Magura Oil, which is filled into the brakes in Germany is greenish - Shell Naturelle.
> Unfortunately Shell USA doesn't sell (import) that same stuff. Shell USA says that this
> (environmental friendly) oil is too expensive for the American market. Magura USA could get it in
> a special load (a boat load?) but it probably would last to the year 3000.
>
> Magura USA searched high and low and ended up with Finish Line Shock Oil No 5, which is actually a
> mineral based synthetic oil and is of a reddish colour. Finish line shock oil is also
> environmental friendly and if you can trust the folks at Shell, it will mix with the original
> Shell stuff. It also has a better lubrication value than even the original German Shell. "
>
> ...too expensive - how depressing Finish line stuff is probably pretty costly too given
> it's niche.
>
> Probably best to use cheese then
>
> ian
>
>
>

--
Med vänliga hälsningar /Kind Regards

/Torsten
--
Torsten Lif Senior Software Engineering Specialist Rational Software Nordic AB, IBM Software Group
Box 1128, Skalholtsgatan 10, SE-164 22 Kista Office +46 (0)8 566 282 00; Direct +46 (0)8 566 28 332

Nordic Rational User Forum - the Call for Papers is now open! Share your Rational product expertise.
Submit your application today at http://accelerator.ericsson.net

 

[Chris Champion]

I find it interesting that I read this post minutes after reading Magura's FAQs:

>Hi guys, I have tuned my MAGURAs with motorcycle brake liquid. What do you think about it? Thank
>you for buying in the near future another set of MAGURAs! Why? Heck, what you have done will for
>sure destroy the inner seals of your MAGURAs because the brake liquid is very aggressive. Never use
>brake liquid on your MAGURAs neither on the rim nor on the disc brakes. Only use MAGURA blood
>mineral oil (which is even biodegradable, because we respect our environment) or low viscosity
>mineral oil.

I'm guessing that Auto brake fluid would do the same thing... I'd err on the side of caution and use
good old Mineral Oil on my very important brakes...

Chris Champion Vision R40 SWB Double Vision R85

Torsten Lif <[email protected]> wrote in message news:<[email protected]>...
> OK, so this is a VERY late follow-up to this thread and I fully understand the issues some have
> with re-beating dead horses, but...
>
> IF you're hard-put to find suitable replacement oil for Magura hydraulics in the US, go to some
> local BMW service shop and ask for their power-steering/brake-booster hydraulic oil. BMW and Audi
> both use (at least in some models) a combined hydraulic system for brake- and steering servos. I
> know this the hard way, from having owned an old Audi with leaking steering boosters. The "BMW"
> oil I bought once was considerably thinner than the "Audi" grade I usually got, and the $20 quart
> ran through the Audi's leaks in a week whereas the "Audi" stuff would last about a month. BUT,
> during the brief period I had that "BMW" brand bottle of oil sitting in the trunk, waiting for
> when I'd need to pour it in, I sheared a Magura line on the Linear and had to refill+bleed.
> Knowing how hard it was to find Citroen stuff (I was living on Long Island, NY, at the time), I
> used some of the "BMW" stuff and it's still in the Magura system today, 6+ years later.
>
> OK, so maybe German stuff isn't much better than French in the US right now, but at least there
> are a lot more BMW's than Citroens on the roads, so there should be shops.
>
> /Torsten
>
>
> Ian D wrote:
> > Blimey - you're right - a country with no Citroens - how queer
> >
> > From http://www.execulink.com/~dtierney/wmc/Magura/geninfo.htm - lots of Magura info for
> > americans:
> >
> > "Magura Oil, which is filled into the brakes in Germany is greenish - Shell Naturelle.
> > Unfortunately Shell USA doesn't sell (import) that same stuff. Shell USA says that this
> > (environmental friendly) oil is too expensive for the American market. Magura USA could get it
> > in a special load (a boat load?) but it probably would last to the year 3000.
> >
> > Magura USA searched high and low and ended up with Finish Line Shock Oil No 5, which is actually
> > a mineral based synthetic oil and is of a reddish colour. Finish line shock oil is also
> > environmental friendly and if you can trust the folks at Shell, it will mix with the original
> > Shell stuff. It also has a better lubrication value than even the original German Shell. "
> >
> > ...too expensive - how depressing Finish line stuff is probably pretty costly too given it's
> > niche.
> >
> > Probably best to use cheese then
> >
> > ian
> >
> >
> >
>
>
> --
> Med vänliga hälsningar /Kind Regards
>
> /Torsten
> --
> Torsten Lif Senior Software Engineering Specialist Rational Software Nordic AB, IBM Software
> Group Box 1128, Skalholtsgatan 10, SE-164 22 Kista Office +46 (0)8 566 282 00; Direct +46 (0)8
> 566 28 332
>
> Nordic Rational User Forum - the Call for Papers is now open! Share your Rational product
> expertise. Submit your application today at http://accelerator.ericsson.net

 

[Rorschandt]

[email protected] (Chris Champion) wrote in
news:[email protected]:

> I find it interesting that I read this post minutes after reading Magura's FAQs:
>
>>Hi guys, I have tuned my MAGURAs with motorcycle brake liquid. What do you think about it? Thank
>>you for buying in the near future another set of MAGURAs! Why? Heck, what you have done will for
>>sure destroy the inner seals of your MAGURAs because the brake liquid is very aggressive. Never
>>use brake liquid on your MAGURAs neither on the rim nor on the disc brakes. Only use MAGURA blood
>>mineral oil (which is even biodegradable, because we respect our environment) or low viscosity
>>mineral oil.
>

I purchased several British sports cars with bad brakes because the owner(s) thought that DOT 3
fluid would be as good as Castrol fluid or silicone. What happens is: all the rubber parts that come
in contact with the oil get damaged and must be replaced because the DOT 3 fluid is caustic to them.
It could be the Maguras will suffer from a similar problem, but I am merely extrapolating.

rorschandt

 

[Tom Sherman]

rorschandt wrote:
>
> I purchased several British sports cars with bad brakes because the owner(s) thought that DOT 3
> fluid would be as good as Castrol fluid or silicone....

I am writing a book. Its title is "The Reliable British Sports Car - A Work of Fiction".

Tom Sherman - Quad Cities USA (Illinois side)

 

[Tom Thompson]

"Tom Sherman" <[email protected]> wrote in message news:[email protected]...
>
> rorschandt wrote:
> >
> > I purchased several British sports cars with bad brakes because the owner(s) thought that DOT 3
> > fluid would be as good as Castrol fluid or silicone....
>
> I am writing a book. Its title is "The Reliable British Sports Car - A Work of Fiction".
>
> Tom Sherman - Quad Cities USA (Illinois side)

With electrical systems by Lucas, The Prince of Darkness.

Tom Thompson Former MGB and Jaguar XJ6 owner and current TE driver.