Hi opt! Glad to see you are still on here as you have helped me many times before. Got a 98 sportsman 500 and the last few weeks I have had poor brakes. The hand brake squeezes all the way and barely stops the machine. I have had to add fluid lately so I assumed it was a leak but can't not find a leak anywhere! Tonight I had to change the recoil and a tie rod end so I did some invesagating and found that the front brake pads were wore down. So i stock an extra set so I changed them and that did not change the light pressure I get from the hand brake. I pumped the handle for about 10 min. And could not see a single drop of brake fluid anywhere so I don't know what's going on. Any ideas?

 

Try a mity vac first and see if you can bleed any trapped air. You can also clamp off the hose close to the master cylinder and and see if it primes up. If it doesn't and you can't see any leaks from caliper seals or lines or at the line block,then I'd replace the m/cyl piston and seal kit.This model was bad anyway about the master cylinder piston seals wearing and sucking air. Item #5. Dirt Cheap Yamaha, Polaris, Suzuki & Kawasaki OEM Parts & Accessories – Cycle Parts Warehouse

 

I do not have a mity vac, I can assume what it is but I am not sure exactly what it is. I went out and pinched the line close to the master cylinder with a pair of need nose vice grips and I do have a lot more pressure better than I did before but I also noticed a swish suck noise when I was pumping the brake. so I don't know exactly what that is. tomorrow I am going to change the tranny oil seeing how it has been a couple of years so I will try to bleed the lines and see if I get any air, it acts like there is air in the line or a leak but I brought the wheeler in on clean concrete and pumped and pumped and not a drip anywhere but the fluid has to be going somewhere. unless it is just such a small leak...

 

I went out there and pinched off each line one at a time then tried the brakes. when I pinch off the top rear line that goes to the rear caliper I HAVE PRESSURE :-). Bit I can not see a leak or any idea why this is happening. any ideas as to my next step?


thank you OPT

 

They don't show it on the parts list,but the rear caliper has the piston seals and also has two small o-rings that go between the caliper halves. This might be the problem if they're seeping air.Dirt Cheap Yamaha, Polaris, Suzuki & Kawasaki OEM Parts & Accessories – Cycle Parts Warehouse http://www.ebay.com/itm/like/231588784265?ul_noapp=true&chn=ps&lpid=82 This is the description on the seals from another supplier:
"Kit includes: 6 oem style seals, 2 orings for each piston and 2 small orings that fit between caliper halves."