I have a 500 HO, Last weekend I was using it and started hearing a squeel from the rear end. I started feeling the quad drag and when I looked the rear caliper and rotor were pretty hot. I let it cool and trailered it home to take a look.
When I got the caliper off the pads are in good shape but the piston will only slide back about half way, I got on it with a big C-clamp to push it back all the way and It seams froze.
I have not unhooked the break lines yet. On any of my other vehicle the piston should push all the way back in when changing brake pads.
Has any one had similar issues with the the rear caliper? The boot around the piston looks good. The piston does move about 1/8", enough for the pads to contact the rotor. Is there any rebuilding of the caliper or am I going the need to change it.
Any advice from experience would be great.
Thanks,
Deerkiller

 

Can order caliper piston and seal kit separately if piston corroded,pitted.

 

Thanks,
Will i be able to see a pitted piston if I remove the pads and extend it?
That sounds like what might be going on.

 

most of the time your better off pushing the piston out to really see it but if you look around the boot you should see wear its rusted/corroded. like he said by a rebuild kit for it and clean it up real good. imo.

 

I took a look last night and did see rust around the boot. I usually keep it cleaned but i guess moisture stays in there. The piston doesn't get alot of use so I suppose it's prone to rust.I'll get a kit tonight and change it.
Thanks for the input.
Deerkiller

 

OPT,
Sounds like you have/work in a Polaris shop.
I checked with a couple of shops nearby. The one needs to order the seal kit,(looks like 2 seals and a boot), $42.00. The other has it in stock, $48.00. Upstate NY
For 3 rubber parts, you might be kidding me.
Just for grins, What is the retail price at your shop for the seal kit, '04 1/2 Sportsman 500.
I think what happened was the boot around the piston got pinched and let moisture in and got a little corrosion on the cup of the caliper where the boot seals.

The plunger that the rear brake pushes against doesn't look like it is contacting the brake lever. Is there any adjustment for the brake lever or the plunger. The rear brake never worked very well. I only us it to get it into Park and high range.

 

it needs to be bled but cant be bled with a frozen caliper.

 

Thanks Mechanike,
I'll fix the caliper problem then bleed it. I'm thinking the cylinder on the rear brake may have a problem as it looks like it is pushed all the way in. I'm hoping once I get it bleed and some pressure in the rear caliper the rear cylinder will get pressure as well.
It's pissing me off about the price of Polaris parts. I can get a loaded chevy caliper for the price I'm paying for a seal kit.
Deerkiller

 

<div class="FTQUOTE"><begin quote>Originally posted by: Deerkiller

OPT,

Sounds like you have/work in a Polaris shop.

I checked with a couple of shops nearby. The one needs to order the seal kit,(looks like 2 seals and a boot), $42.00. The other has it in stock, $48.00. Upstate NY

For 3 rubber parts, you might be kidding me.

Just for grins, What is the retail price at your shop for the seal kit, '04 1/2 Sportsman 500.

I think what happened was the boot around the piston got pinched and let moisture in and got a little corrosion on the cup of the caliper where the boot seals.



The plunger that the rear brake pushes against doesn't look like it is contacting the brake lever. Is there any adjustment for the brake lever or the plunger. The rear brake never worked very well. I only us it to get it into Park and high range.</end quote></div>

[img]i/expressions/face-icon-small-happy.gif[/img] Yep price sounds about right.SOME dealers do add above listed price but we dont! Assist brake has never had strong stopping power! Master cylinder small compared to hand brake. Replace seals,clean or replace piston,bleed as MECHANIKE suggested. OLD mechanical assist rear brakes on old Trailboss and early Sportsman had better stopping power. PLUS pedal brake designed as ASSIST/EMERGENCY brake only,not to be used constantly like the Jap models! DONT compare atv parts with auto parts on price, they dont make thousands of these like car parts! I'm training an ex Ford mechanic and he cant believe prices of atv parts,NOT just Polaris,but all powersport parts!

 

Yup, I thought the price had alot to do with economy of scale.
10,000 Chinees putting out 1000's of chevy calipers really can brink a part price down.
How often does a sportsman rear brake need rebuilding? not too often. I guess the same goes for a $13.00 quart of Polaris synthetic oil. I change my oil once a year or so. maybe every other.
Here is one more question about my brakes. Not to beat this horse to death but.
When I bleed the brakes using the hand brake lever, will I also need to pump the foot brake to bleed that half of the line. Is that cylinder at the foot brake what you are calling the master cylinder? I think it might be seized as well because the plunger is pushed in and is why it is not contacting the foot pedal. Will that plunger extend when I bleed the lines? or is it spring loaded like the hand brake.
Thank for the reply if you get the chance.
Deerkiller