01 Sportsman 500 Rear Master Cylinder
 

Has anyone rebuilt master cylinder? New is $125 Kit is $22.00
any explanation on how. I had taken it apart and cleaned still does not work correctly.


Any ideas?

Seal kits like you mentioned are cheap,but you have to split the caliper if I remember correctly and the two small o-rings seal the caliper halves.http://www.ebay.com/itm/98-99-2000-2001-Polaris-Sportsman-Worker-Rear-Brake-Caliper-Seal-Rebuild-Kit-122-/270894575205?pt=Motors_ATV_Parts_Accessories&hash=item3f12932e65&vxp=mtr

Really the rear master cylinder is activated by the foot brake only and is only a emergency back up in case main hand brake which operates the front brakes (60%) and rear brake (40%) simultaneously ever fails.

That's why the rear caliper has two separate hydraulic lines going into it.

I know people who set the rear foot leaver not to work on purpose because people find they are standing on it without realizing while riding and prematurely wear out the rear pads.

Between the main hand brake and the EBS the foot brake would not be a $125 part worth fixing to me.

The small master cylinder has rebuild kits now rather than replacing the whole master cylinder. Main reason I found over the years is that most people never use the foot brake that often,seals dry up and the foot brake is useless because of it. Best to at least use it every now and then and you won't have problems with it.http://www.ebay.com/itm/1998-2009-Polaris-Sportsman-Rear-Foot-Brake-Master-Cylinder-Seal-Repair-Kit-/281401394521?pt=Motors_ATV_Parts_Accessories&hash=item4184d48559&vxp=mtr

Rear Master Cylinder
 

Thanks for the replies, will not worry about fixing it, Hand breaks work fine.

Just my :twocents: on this one. This is one safety device that Polaris has that really does work along with the etc switch in the throttle housing if snagged by a tree limb. If any of the 3 main brake lines rupture,get snagged ,you're up a creek with out the auxiliary rear brake that can at least stop you in an emergency.Has a separate chamber in the caliper that puts pressure on the piston. That's why I recommend using it every now and then to keep the master cylinder seals pliable and working.

You should see my dads 1997 Sportsman 500 and with no EBS. Back then the back up foot rear brake was Mechanical cable operated not Hydraulic.
Even when new you could stand on the foot brake and would be lucky if you could feel it slow you down on its own.LOL

I actually like the old mechanical systems better than the later hydraulic ones. Kinda the same problem scenario on this too as the hydraulic systems as I had a bunch of owners from the Trail Boss,Trail Blazer,Sportsmans,etc come in complaining on the foot brake wouldn't stop or slow it down enough. Most people didn't use them often and as the pads wore you had to turn the adjuster screw on the outer assy to where the bottom of the foot pedal was about 1/2" from the floor board to keep it adjusted properly. I could get out in the parking lot and lock up the rear tires when they were adjusted correctly. The adjuster screw just pushed the activator pin #25 against the rear of the piston.Even the owners manual had instruction on keeping the brake pedal adjusted,but hardly anyone did. Dirt Cheap Yamaha & Polaris OEM Parts & Accessories – Cycle Parts Warehouse