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How to Bleed ATV Brakes | Yamaha YFZ450R | Partzilla.com


Hello, John Talley here with Partzilla.com. Today I’m going to show you how to bleed the
brakes on our 2009 Yamaha YFZ450R. Really simple to do. Let me go grab a couple of tools and we’ll
go right through it. Listen, this is only going to be a skill level
one. It’s going to be really simple, and I can
prove that by the fact we only need a couple of tools to pull this off. Which tools? Well, a Phillips screwdriver, an 8mm wrench,
some type of container, and then a length of quarter inch hose. Now, as far as the parts go, there’s only
one. All you need is some DOT4 brake fluid. Me? I prefer to use whatever the OEM manufacturer
put in the machine when it was brand new. So, once you’ve got your tools and your DOT4
oil ready, we can jump over there and I can show you how to do it. Alright I’m going to go ahead and lift this
one up and get the front tires off, but that’s not absolutely necessary. You can actually bleed it with it sitting
on the ground. I’m just taking it off so you’ll be able to
see what I’m doing. Alright, let’s start by taking off the cover
on the reservoir on the master cylinder for the front. Just a couple of Phillips and if they don’t
break loose immediately using just a regular Phillips screwdriver, you may want to use
an impact Phillips. Take off the cover, clean up this plastic
section. then there’s a little rubber diaphragm that
needs to come out. Yep, looking like Coca-Cola in there, so it’s
definitely time for a flush. The name of the game here is clean, because
you don’t want to introduce any contaminants into the system, whether it be dirt, water,
or whatever. Alright, so we’ve got our reservoir opened
up and all we have to do now is connect a length of hose to the bleed valve right here
and then that needs to go into some type of container. I just drilled a hole in the top of a regular
quart of oil that we had already used. So, here’s the process. Pump this up, hold, open the valve til it
bottoms out, then close the valve and repeat. I typically do this pretty much every time
I go through a brake pad change, so that’s when it needs to happen. That or annually. Because brake fluid is what they call hygroscopic,
and it attracts water into the system and that’s what we don’t want to stay in there. Plus, the fluid that down at your caliper,
well, it’s pretty much staying there the whole time and every time it goes through a heat
cycle, that starts to break it down a little bit, so it’s important that you get quote-quote
new fluid down into the caliper area. As you’re doing this, you need to keep an
eye on your reservoir because what you don’t want to have happen right now is to introduce
air into it, because I know this system is working like it’s supposed to so I don’t want
to have to start over by forcing an air bubble all the way down and through the caliper. I’ll do this in between 20 and 25 times, checking
along the way to make sure I still have enough fluid. Alright we’re getting a little bit close,
so I’m going to fill it back up and keep going. Do this side a few more times and then we’ll
head over to the left and then do it. Alright, we’re going to go ahead and fill
this back up and go switch over to the left side. Tighten up. Same procedure as the right side. Let’s go take a peek at that reservoir again
and see where we are. Yep. Alright guys, that should do it. Only thing we need to do now is set our level. Tighten than back down all the way, then don’t
forget to put your dust and dirt cap back on. Alright, we are going to refill it to about
right here, just below that upper section of the sight window. alright, there’s one thing I want to caution
you on when you go to refill and set the level on the reservoir. If you have old brake pads and you fill it
all the way to the top and you put new brake pads on it later, well guess what? That fluid is not going to have anywhere to
go. So, if your pads are worn out, don’t take
it all the way to the upper level. I know that we just replaced the brake pads
on this machine not long ago, so, I’m good to go up to that upper mark. So let’s get it filled up. That’ll do. Now at this point we can co ahead and put
the diaphragm back in along with that plastic spacer, and then the cover itself. Alright, with the front finished up, let’s
move around to the back and get it taken care of. Alright, we’ve got our dust cap out of the
way, let’s go and connect up our quarter inch hose. And the rear reservoir is actually up under
the seat. And that is it right here. Put together about the same way. Nylon spacer, rubber diaphragm, and then just
the cap. Alright, we’ve got it opened up, I’m going
to go ahead and top it off and we’ll start pumping it through. What we’re going to do is you’re going to
pump it up, hold, open the valve, let it bottom out, close the valve, and then repeat. Do it about 10 times then we’ll check the
reservoir. See where we are. Yep, time to fill up. To give it a good chance of getting most of
the fluid flushed out, we’re going to fill up the reservoir probably three or four times
to really force out that old fluid. Alright, we’ll refill it one more time, pump
it down, then we’ll set the level. And the mark we’re heading for– once again
I know we have new brake pads on the back of this one– we’re gonna be heading about
right here. And that’ll do. Let’s go ahead and put our cap and diaphragm
and little nylon piece back on, and we’re pretty much finished guys. Alright, now just need to pull the hose off,
put that dust cover back on. Well alright guys, that pretty much wraps
this one up. all that’s left for me to do is put the tires
back on and get the seat in there. So, if you need any parts for your machine,
why don’t you come see us at Partzilla.com and we can get you taken care of. If you have any questions or comments, leave
them in the section below and I’ll do my best to answer them. Til next time we just want to say thanks for
shopping with us at Partzilla.com and we will see you in the next video. Have a great day.

5 thoughts on “How to Bleed ATV Brakes | Yamaha YFZ450R | Partzilla.com

  1. IT IS THE SAME PROCESS AS THE YAMAHA RAPTOR 350? I. GOT AN 07 THAT IT'S GIVING ME PROBLEM WITH THE REAR BRAKES. I GO NEW PADS NEW OIL AND STILL DON'T HOLD FOR SOME REASON.

  2. *PLEASE HELP*
    Hi to whomever is reading

    When ever I pull my front break, my rear break pushes out and kind of counteracts the rear break. And vice versa. Why?! I bled the breaks there’s no air in there. Please help I can’t find anything online – maybe I’m not wording it correctly.

    Thanks in advance!

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