John Talley here with partzilla.com.
Today we're going to be taking a look at the braking system on our Polaris Sportsman 850.
Specifically, what's going on is I've ridden this machine and you go to hit the brakes
and it's making this God-awful grinding sounding noise.
So we're going to go ahead and take a look at the front and rear.
For this particular machine it actually uses the same brake pads for the front and rear
system,
so there's only one part number you need to keep up with.
Alright, so give me a couple of minutes, I'm going to go ahead and life it up in the air
and I'm going to pull that right front tire and start pulling it apart and see how it
looks.
So let's get started.
Alright, what we want to do is go ahead and get this thing cleaned off the best we can.
Get most of the dirt out from around that boot.
Also, inspect the boot while you're doing it.
Make sure it doesn't have any rips in it.
Next, we want to go ahead and compress the piston back inside the caliper.
I usually pick that point right there.
Just start prying on it.
Once it opens up just a tick, then you can get your screwdriver and get between the pad
and the outside of the caliper itself.
and we just want to compress the piston all the way in there.
that way, we'll have enough room to get the new pads back in there because these are--
once you'll see in a minute-- are completely worn out to the point of being a little absurd.
It's metal on metal.
Alright, before you take off these two 15mm bolts at the top and the bottom of the caliper
bracket, there's a 5mm Allen at the top.
Go ahead and back it off.
What that's going to allow is that pin to get pushed all the way through-- well, not
all the way through but further back that way you can get the actual brake pads out.
Now we can remove those two 15mm bolts.
Push these all the way back.
Now you can lift off that end, swing it around.
Look at that.
That is just absolutely terrible.
No pad material left whatsoever.
And that inner one is actually about a third of the way cutting through the backplate of
the brake pad itself.
Alright, with the pads out of the way we want to go ahead and pull the backing plate.
What we want to do to make this thing operate smoothly is clean this off with a little bit
of brake cleaner and then we want to put some grease back on these two pins.
We also want to inspect these two boots and make sure there's no tears.
If they are torn, you need to go ahead and replace them.
Alright, we've got the grease on there, everything is cleaned up fairly well.
I may have to compress that piston a little bit further but we'll see.
It doesn't give you a whole lot of room but it will go in there.
I'm definitely going to have to compress that piston in a little bit more.
So what I'm going to do is just temporarily mount it back to the hub.
Get our screwdriver back in there and compress that piston further in so we can get that
other brake pad on.
There we go.
That should have bottomed it out now.
Sometimes you've got to back up to go forwards.
Alright, now there should be enough distance to get those around the brake disc itself.
Not by much.
Alright, there she goes.
We can get our 15mm back in on the top and the bottom.
Don't forget this little 5mm Allen plug up at the top of that upper pin.
And that pretty much does it.
the only thing we need to do is you know just give it a couple of pumps just to make sure
that you know it re-engages the pads on the rotor.
Basically, the other side is a mirror image of this right here.
so it's exactly the same procedure and we're about to go back and do the rear brake pads.
I mean the purpose of this video is to show you just how to do the brake pads but honestly,
this front brake disc is beyond use.
I mean its wear limit should be right at 4.24mm in thickness and it's well under 4mm. so this
thing is not really usable.
I will come back in a different video and show you how to replace this, but for right
now I'm just going to leave it in place.
We'll go ahead and put this back together and move to the back and show you how to do
the rear brake pads.
Alright guys, I've got it set up so we can do the rear brakes on this particular unit.
It's kind of an odd setup in my opinion.
It actually has only one brake caliper and set of pads and it's over on the right side.
the other side?
Nothing over there.
so all of your braking action is handled by this side and then transmitted through to
the other side through the rear differential.
I wasn't in on that design and it wasn't my idea, but that's just the way Polaris does
it.
Alright, as far as replacing the pads it's almost exactly the same procedure as we did
on the front, but I'll go ahead and walk you through it.
Go ahead and collapse the piston into the caliper.
I'll tell you what these calipers are not in the best shape.
I'm fairly certain I'll end up rebuilding them in another video.
While we're talking about other videos, as I mentioned on the front, this rear disc is
not in very good shape either.
But, like I said that is for another time.
All we're going to do today is just replace the pads.
alright, with that compressed in, go ahead and take off that little cap that they have.
Once again it's a 5mm.
From there, let's just get her cleaned up just a little bit.
We'll do this a little bit more once we get it all the way off.
Same setup as on the front.
15mm at the top and at the bottom.
Yeah, they're just worn completely out.
Somebody definitely did not maintain this machine very well at all.
Alright, it's like someone built them a little sandcastle in here.
Alright, same thing like we did on the front.
go ahead and pull that all the way off.
Get these boots cleaned back up, get those pins cleaned up and a little bit of grease
on the end.
Reinserted.
Get those boots up and around there.
Now we can start putting it back together.
Alright, we need to open up that gap a little bit more.
And now she ought to go on.
Just like that.
Get our two 15mm put back in place.
Then we'll put on that little 5mm cap, the Allen. and that'll pretty much finish this
up.
Alright, give the brake pedal a couple of pumps and make sure it's engaging.
Oh yeah.
That clamped right down on there.
Alright, that pretty much finished this part up as far as just replacing the brake pads
themselves.
But like I mentioned on the front, the rear brake disc is in pretty bad shape so we're
going to be replacing it as well on another video.
But as far as just doing a brake pad installation, this is pretty much it.
It's pretty easy to do and if you keep up with it and keep your pads in good shape you
won't have to go back and replace the brake disc like this one is in desperate need of.
Well listen, if you have any questions or comments, if you would just leave them below
and I'll do my best to answer them.
If you need any of the parts come see us at partzilla.com and until next time, thanks
for watching.