- Hello and welcome to another Real Time service video.
This week, we're going to be looking
at Shimano Hydraulic brake systems
and how to bleed them.
(explosive blast)
So, to do a full bleed on a Shimano System,
these are the tools you're going to need.
This is kind of an optional extra,
a pad spacer, which does help,
but you can make do without.
But the things you do need
are some decent allen keys, a 2.5 and a three mil.
We also need a decent Phillips screwdriver,
a seven mil open spanner,
a bleed block, your bleed kit itself,
and I do recommend using,
you know, the official Shimano one.
I tend to find they're a bit better.
We've got some isopropyl fast drying contact cleaner,
some real deal Shimano mineral oil,
and a load of blue towel.
I also choose to wear some gloves.
You don't have to, but just, you know, be careful.
The mineral fluid can be pretty nasty stuff.
So, you know, try and be sensible.
But anyhow, on with the service.
As you can see, we've actually removed a break from a bike.
Now this is basically to aid visually as much as anything.
But it's similar orientation.
If you're doing it whilst it's still on the bike,
we want to get it so the lever here is nice and flat.
That's basically going to aid oil as it comes.
So aid air comes up through the system, when we bleed it.
If you can have that bleed point there,
as one of the higher points in the system,
that's really going to help.
So without much further ado,
we're actually going to start at our caliper end,
and we're just going to, we've got the three mil bolt here.
And we've also got this little circlip.
So we're going to take that out the away.
And now these things...
They like to go walkies.
We're going to put that somewhere very safe,
but not that kind of safe place,
when you put it somewhere, and then immediately lose it.
But an actual safe place where you won't forget.
And we're going to remove our pads first.
We've got a three mil bolt here.
Going to get my allen key, using the square end,
and not the ball end to get it going
and then yeah, you can just spin it out
onto its low torque as required.
We're going to put that somewhere safe.
Now before I started this video,
I've washed my hands.
And if you want your brakes to run
as best as possible for as long as possible,
then you want to reduce the risk of contamination.
Well, that sounds a bit kind of obvious and silly to say,
but then reduce the risk of contamination.
Go into everything with clean hands.
Be careful how you handle your brake pads,
notice I'm touching the back plates
and not the braking surface.
And even when you lay them down,
put them somewhere that is clean.
Clean it, make sure it's clean, no excuses.
And then we're going to look at our caliper itself.
So this is where I'm going to put my gloves on.
Now, gloves are good, obviously,
'cause they protect you from the
nasty and potentially, you know, corrosive
solutions and substances we're using.
But it also means that my hands
have gone in there clean,
and they're going to come out of there clean.
So when I need to handle the brake pads again,
I should be doing so with clean hands.
There we go.
So like I said, if you want to reduce
the chance of contamination, then do it properly.
Get a bit of blue towel before we even start.
We're just going to...
(spraying)
Give this a quick wipe down.
Just, you know, you'd be amazed at how much
(wiping)
dirt...
(wiping)
these can...
(wiping)
get hold of.
(wiping)
There we go.
Now we get our pad spacer and just use,
we're not using it as a lever, okay.
If you're having to lever it back,
maybe on four pots, it can be quite a difficult job,
then just use a tire lever.
And, we're just going to use the flat hand side,
just to press him in.
That is so we can make sure
we can fit the bleed block.
Sometimes, you know, these
systems are basically overbled.
If your pistons can't go back,
instead of just applying more and more
torque and elbow grease,
these pistons can sometimes even shatter.
So what you're going to do
is let out that valve there.
So we let out that bolt.
And if the system is overbled,
then it'll mean you can press these back
into it, so they're flush
and be able to install this bleed block like so,
which should be able to drop in
with just a little bit of slack.
Then we're going to fetch our
retaining pin, retaining bolt
and just pop that in, sorry,
I'm not showing that very well.
You're just popping that in there.
And yeah, just get your three mil
and nip it up.
Just so you know, you don't have
to put the clip on or anything there.
It's just so we,
we're going to get a nice consistent bleed.
Sometimes, you know, people don't like the feel of Shimanos,
in terms of amount of lever throw.
You could potentially, if you wanted to,
get one of these bleed blocks,
and just file it down a shade.
That would mean that when you're bleeding it,
you're essentially overbleeding the system.
So it would reduce lever throw.
This will probably also mean that it's contacting
the rotor bit more if it even warps slightly.
But yeah, it's something you can do
and something people have been known to do.
Next, we're going to get our bleed kit.
Now, before you put a bleed kit away,
it should be clean, you should clean it properly.
Same with these.
However, if you take them out
and they're not clean, clean them beforehand,
let's just do a proper job.
Yeah, there's no excuses not to,
not to have, you know, clean tools and use them properly.
And if you share tools and someone else
isn't pulling their weight and cleaning them,
well, well, well well, you know what to do.
Give 'em a bit of grief, because it's just not on.
Even, I'll always wipe down the excess
that's on the outside of the bottle.
It just reduces the chance of contamination,
which will become somewhat of a theme today.
So we're going to start off,
going straight from the bottle.
And we're just going to put
a little drip of mineral oil in there.
It doesn't need to be much.
That isn't where the oil gets introduced to the system.
But, as I will demonstrate in a bit,
there is a very good reason.
And we just...
There we go.
And then let off that bolt.
This would be the bolt where sometimes
you purge the oil out of, if you are indeed
having to deal with an overbled system.
So you can just undo that
and you might see it overflowing a bit.
That's another thing entirely, another conversation.
So we've undone that bolt
and with the plunger still in the bucket,
we're just going to thread that in.
My other,
going to bring that out there.
There we go.
Now the threads on these bleed buckets are really soft
and any kind of mechanic that says
they haven't cross thread one of these is a liar.
It's so easy to do.
Really gentle, just ease it in
and you'll basically get more life out of your toolage.
It's made to thread easily.
The reason is is that it doesn't damage
your lever and the threads in there,
but, you know, let's just make it easier for ourselves.
And then we get on to our caliper.
The caliper's already clean.
But we're just going to
take our bleed syringe
with a nice long tube
and we're just going to pick up
a fair whack of oil.
This is 'cause we want to push all that oil
through the whole system.
There we go.
We're just going to pop this bit on here.
It just sometimes
quite hard to get on, but that's absolutely fine,
'cause then what we do, is we slide down
this black handle,
(click)
and that snaps on there.
That is to basically mean that it's not going to fall off
as you try and bleed the system.
Next we're going to get our open ended
seven mil.
You'd need to just back this nut off, okay.
Want to use a good quality spanner here, okay.
And make sure it's the right size.
That means that's a no on pliers,
anything like that.
Use a proper spanner and do it properly.
Now, the reason,
as we remove that plunger,
the reason we have a little bit of oil in there first
is that we're going to just
tease it back to begin with.
Not much.
Now we do this for two reasons.
One, we do it to remove any air,
even those tiny, tiny bubbles coming up there,
that we'd potentially be forcing into the system.
And it's also a really good way of inspecting
the color of your hydraulic fluid that's in there.
When we're going to push this down,
even if it gets really dirty up to there,
you can still flush out the system
really, really effectively.
But it just gives you a good idea of what's to come.
And yeah, it's just a good habit to get into.
So next with that nice and open,
if that socket isn't open enough,
it becomes really hard to push the fluid down.
You want to make sure it is open.
There we go.
And you can actually see it filling up
in the bucket here, okay.
What I've done in the past is actually use,
alternate between Shimano fluid and say some,
I don't know, some aftermarket OE fluid.
Sorry, aftermarket fluid.
And what that is, is because it's different color,
it means when you're bleeding clean fluid
that isn't contaminated with oil,
such as, sorry, contaminated with dirt such as this,
it means it's really easy to see
when you've bled the full system.
But logic dictates that
that's only got so much capacity
and amount we put in there,
it will have passed that.
And then, using this lever,
we're actually just going to turn that
just so it's almost there.
And you can actually see it, it's just threading the socket,
sorry, threading the nut a bit.
And then, using our seven mil, with moderate torque,
we're just going to nip that up.
You don't need to be swinging off it.
But yeah, it certainly doesn't help
to risk damaging parts.
So now we're going to detach our syringe.
So whilst, if you actually just gently put it on the lever,
'cause you want to create a vacuum
so it doesn't spray oil everywhere, okay?
There we go.
And basically, as you're pulling on the lever
and you disconnect it, it will actually be
drawing air into the syringe.
Problem is when you have a pressurized system,
and eventually take it off, it can spray everywhere,
which again, increases the chance of contamination.
But there we go, that's all good.
So I'm just going to pop that down.
And now we're just going to
put this oil, which is clean,
back in there.
I'm also then going to go to the top.
And this will just basically make your life easier, okay.
We're just going to actually,
withdraw some of that fluid.
Because we're going to do some,
a bit of the old twisties later on.
And what that means is,
it just reduce any chance of spillage.
This will then be, can potentially quite contaminated oil.
Well then this stuff's actually really clean,
which you can then discard.
Also then, I want to discard it,
I would then clean interior and exterior
of the syringe to make sure it is all absolutely perfect.
But before we finish off with the caliper,
we're going to make sure it's nice and clean
with some isopropyl alcohol.
This is called Specialist Fast Drying Contact Cleaner.
It's essentially isopropyl alcohol.
Sometimes you can obviously use brake cleaner.
But sometimes that's kind of,
well, I don't feel it's such an effective cleaner
as alcohol basically.
Sometimes, although it's very good,
sometimes they are slightly different.
Because that is a thoroughly clean caliper.
And then we're going to go to our lever.
So like they do in Westlife concerts,
I don't know if they're still going,
I'm going to stand up out the stool.
That's when you know it's getting dramatic.
Right.
So now, when we're bleeding this lever,
we want to do it properly.
So some people would then just
pop the plunger in, take the bucket out,
reinstall that nut and jobs are good.
What we're going to do is
increase your reach, which actually
increases the amount of volume within the lever,
ever so slightly, not much.
But also,
going to with our Phillips head screwdriver.
We're going to back out this free stroke which, yet again,
ever so slightly, increases the volume of that.
And when people struggle with bleeds,
and they struggle to get good consistent bleeds,
it's often because of this.
So with those both backed off,
we just move the plunger out the way.
And we begin to just...
You don't want to just be holding down this lever,
you kind of want to be flicking it
just a prompt any air out,
and then whilst doing so,
we can go to the next stage,
which is basically dialing in and backing off
this reach adjust, as we flick the lever.
And you'd be amazed at how much more air
this can, you know, prompt out.
So it's super useful.
Then once we've kind of done a bit of that,
we then put the lever back up full extension,
just to increase that volume again.
And then we're going to do the same
with this one here.
A lot of people perhaps, don't realize
about the free stroke adjustment in these Shimano brakes.
It's really important that once it's,
you know, fully fully in,
you're not just absolutely mashing it,
'cause you can kind of damage the internals a bit.
But yeah, you can just see
the little bubbles coming out there.
And then with it,
again, kind of fully backed out,
we're just going to tap the lever
to do any last prompting.
That looks pretty good to me.
So what we do is, we gently pop that plunger in.
We're going to just,
there we go.
So you can see, you know,
that system's absolutely brimmed now.
And you can see it flat on here.
Now when we're putting in these bleed bolts,
this little nut here, it's really important
we're not putting it in directly flat,
because it sounds stupid,
but that could actually trap air underneath it.
So what we're going to do is,
it's really hard to show you here.
We're just going to put it in at a slight angle, okay?
Doesn't have to be much, but that means,
that as it's put in, it's just going to force any air,
it's going to give somewhere the air to ago.
We're just going to thread it in
and go to the other end, just to
nip that up.
Then we...
We're also going to use this opportunity,
before I do the full decontamination,
to put this little fella back on.
One last reach for the cleaner.
Absolutely no excuses, especially
when it's out of the bike to give it
just a bloody good clean.
(wiping)
There we go, even the hose, why not hey?
Then I'm going to just back off
that reach adjust.
This is about the center before.
Then dial in that free stroke, like so.
We don't want to be over torquing that,
just nip tuck, it's absolutely fine.
If it's on the bike,
we say with Shimanos you can
basically measure it by point and free stroke really easily
without actually literally do it with a ruler,
do it with some verniers
and you'll be absolutely sweet.
So everything now is, well,
it's about as clean as you could hope it to be.
So we're going to reach for three mil.
Undo that bolt there, like so.
Moving it.
There we go.
Now, as you might have gathered,
I am a bit fussy when it comes to contamination.
Something I actually would do at home,
and you're going to laugh,
is actually just got a little spray bottle of water.
Now water is great, just because it can see,
if water is beading lots then there's kind of
a lot of oil there.
So I would just spray everything with water,
which I'm not going to do today.
I'm going to spare you the
tragic extent of my fear of contamination.
So now everything is absolutely clean.
There is no risk of
contaminating these brake pads
because I take off my gloves to reveal
these freshly manicured hands.
Me and Doddy actually go down on a Friday afternoon,
manicure, pedicure, every week.
It's an absolute pleasure.
Anyhow, so touching the back of the plates,
we're going to slide them in through the back of the caliper.
And they can just drop in.
Then we reinstall this little bolt here.
He says confidently, as it doesn't seem
to want to go in through the center.
There we go.
Okay, you can just spin that in.
And going to the end just to nip it up.
Last but not least, this little devil.
To just clip on there and that would make sure,
if that were to wobble loose,
it's not going to go anywhere.
And there we have it, guys.
That's how to do a full bleed on a Shimano hydraulic system.
Now, be careful how and where you dispose your oil.
And be sure to give everything,
all your tools, a thoroughly good wipe down.
Now if you want to stick with the Real Time service videos,
click down here to see me service a rear shock.
And click down here to do an air spring service
on a RockShox fork.
As always, don't forget to like and subscribe
and hit that notification bell.
Thank you very much, and we'll see you next time.