about a week ago i went on a trail ride on my stache and while i was driving back from
the trailhead someone in a chrysler 200 lightly tapped me from behind now they fled the scene
i pulled over and i got out and i checked everything my bike rack was slightly bent but
everything still looked secure so i continued on home unfortunately about 10 miles down the road my
bike fell out of the rack and onto the road when i got home and i was able to fully assess the damage
i found out that i had a couple minor issues and a couple issues that were worse the minor issues
were one of my bar ends my hand grips just got scuffed a little bit and my seat got a scuff
the other issues had to do with my derailleur it got bent it hit the ground pretty hard
i've bent it back into shape and i think i'm shifting pretty good now the other issue was
the bars spun and so all of the cables that go to the back of the bike got stretched a little bit
the dropper post in the derailleur shifter cable seems to work fine and seems to be okay the hollow
brake line though it was stretched pretty bad and up near the reservoir it has a crimp in the hose
and so i doubt the integrity of that now and so today we're going to replace it the first thing
i'm going to do is i'm going to take the new brake hose and i'm going to zip tie it along the length
of the old brake hose now once i've done that i take into account just how much of this hose
has to go inside uh in front of the jam nut there then i take a pair of cable cutters and i cut it
nice and clean you want to use a pair of cable cutters so that you don't mash the
line you don't want to crimp that and now i take a pair of cutters remove all the zip ties
before we work on this brake line it's good to remove the rear wheel because if we get any uh
brake fluid onto this rear rotor that's a bad thing after i've made sure that the derailleur
is in the highest gear the smallest cog on the cassette and i've loosened the axle a little
bit i position myself behind the bike and i put my torso into the wheel to steady it i then disengage
the clutch on my rear derailleur and i grab the rear derailleur and fully extend it and open it up
then i take out the axle the rest of the way once the axle is removed lay that to
the side and then i grab the wheel and i just drop it right out of the chain and derailleur
i also want to get the brake pads out of the way because if they get any mineral oil or
brake fluid on them they're going to squeal because i want to reuse these pads
i'll use a non-marring bicycle lever it's plastic that way i can push the pads and the
pistons back into the caliper now the pistons are pushed back i can remove this set screw
and then i can slide the brakes out
just set those aside now that we've got the brakes out we're going to install the piston block
the piston block is retained with the same set screw
what i've done now is i've positioned the bike so that the caliper is the lowest point in the system
and i flex tied the handlebars so that the reservoir is the highest point in the system
when i'm at this point i take a coffee cup and then i poke a hole through it then i take a zip
tie and i feed it through the hole then i take the coffee cup and i zip tie it to the chain
stay right below the banjo bolt right like that before i open the banjo bolt i go ahead and i
take the cap off of the reservoir so that air can come in and the fluid can drain more easily now
that we've got the reservoir cap off it's time to remove the banjo bolt and let all of the fluid out
now we finish cutting the cable ties that are holding the brake line to the
frame now that the line and reservoir are drained we can remove this nut and there we have the olive
and the end of the brake line shimano provides a few items with the new brake line they provide you
a new flange nut they give you this piece which is called the olive and they give you this piece
which is called the barb they also provide new o-ring seals that go into this connection point
and the last thing that comes with the kit is they give you these blocks which are used to hold the
line while you insert the bar i'm not going to use that i found this you can use it to hold the line
and then push the barb in off of my other brake line i had to salvage this cap the first thing
that goes on is this cap then you put on this bolt or flange nut i think it's called that i hope i'm
not calling it the wrong thing the whole time through here then you place the olive on there
okay we've got it all lined up now we're ready to just drive it home
all right we're now ready to insert our new brake line into the reservoir
and then we slide in that olive and then we start screwing in this flange bolt
now as we tighten this down it is going to smash that olive and that olive is going to seat
very tightly against the line and the barb inside now we run this cover up and snug it in
now we want to roll this line out the line comes rolled up from shimano from the factory
so you want to lay this line out and you want to make sure that it is laying the way it naturally
wants to lay and does not have any kinks in it once we've got the line running naturally
we want to go ahead and take our o-rings and just place them in the fitting
and they'll sit there they'll stick because of the grease we then insert the bolt and just hand
tighten that making sure the o-rings are still intact let's go ahead and run that all the way in
and now i just loosely zip tie everything back into place
now this i think is the easiest part that most people get daunted by
you just want to make sure that your reservoir is the highest point in the system
and we fill from the caliper to push all of the air up the line out through the reservoir
and make sure the reservoir is full of mineral oil to do this part i highly recommend this
overflow cup from shimano it screws right into the reservoir and it lets brake fluid come into it
but it will not drain back out i've also seen a few of these that are opaque i recommend something
translucent like this because you want to be able to see when the fluid is starting to fill this cup
we'll now fill this syringe with mineral oil
all right now we take this little rubber cap off of this fill nipple and then we loosen it
now i leave the wrench on there for this next step because you're going to want to tighten
it and you want to make sure that you have free range of movement to be able to tighten
it back so i leave the wrench sitting on that chainstay then i get my mineral oil syringe
and i place the hose over the nipple and i begin to push mineral oil into the system
while we are doing that we are always looking up at that fill reservoir to see when mineral
oil starts to appear there and here it comes that's good okay i'm gonna tighten down the
nipple and remove the hose on my syringe so i'm gonna go ahead and take this cap off
when you take the cap off you depress this little needle down into the hole into the seat so that
it stands like that and then you know the fluid can't flow back then you start removing this cup
there it's removed i see nice clean mineral oil coming out there remove the piston block
the brakes were actually a little bit more war than i thought they were
and so i'm going to drop a new set of breaks in here
and we don't want to even think about squeezing that rear brake until we get the wheel in there
okay i then go ahead and squeeze the brakes a few times in order to fill
the cylinders and push the pistons back out and then i remove the reservoir cap again
and now with my little fill bottle i go ahead and just top off my reservoir
at this point all that's left to do is to tidy
up all of the zip ties in the cockpit and then go ride later