I have a 2004 500 ac 4x4, ususally back brakes work awsome. Went riding at a river couple weeks ago, washed it today and went to put it in the garage and they wouldn't work at all, the pedal goes to the floor. I looked at the sight glass in the cylinder, it looks half full. Should the cylinder be completely full?

 

nope, you should be able to see the level in the glass. You might want to check for a leak, otherwise the only way to get the air out of those things is to unhook the linkage and pump fluid from the caliper into the cylinder. If you do that you get a small air pocket out of the cylinder and then you can adjust the linkage and then your back brake works great!

 

To check for a leak, do I just pump the brake and look for fluid coming out? I have pumped it quite a bit hoping it would work out, there is no fluid anywhere so far. How would I go about pumping the fluid into the cylinder? Thanks for the help.

 

Yes, you should see some fluid if there is a leak- like wetness on a line or fitting, or some dirt that is wet on the wheel or wheel well that won't dry. To bleed the rear brake you can use one of two things- a Mighty Vac or a oiler (the kind that you would see someone oil gears or something with). Most people don't have a mighty vac so I will describe how to bleed the brakes with an oiler. First you need a oiler- one with a lever pump not the kind that you push on the bottom. Fill it with clean brake fluid- the wilwood stuff you get from your dealer is best because its nice high temp stuff. Next get a piece of clear hose that will fit over the spout of the oiler and is small enough to have a air tight seal over the brake bleeder. Next, remove the pin out of the brake linkage so the rod going to the master cylinder is relaxed. If this is not done you will not be able to fill the master cylinder with fluid. Remove the cap off the top of the master cylinder along with the rubber bladder. After that pump some brake fluid out of the oiler untill you stop seeing air bubbles in the line. Attach the hose to the bleeder on the brake caliper and crack the caliper open and start pumping. Don't worry if it over flows from the master cyl.- you can take a clean rag and remove the excess later. While pumping you want to make sure you don't see any air bubbles going through the line otherwise you will have to start over. Once you feel that you have filled the master cylinder enough close the bleeder and remove the hose. At this point you can remove any excess fluid from the master cylinder and put the bladder and cap back on. Then you can adjust the linkage on the rod untill you have a "good" feel on the pedal. Reinsert the pin and you should have a working foot brake!

 

Thanks alot for the great instructions, might take a couple days for this to get done. I need to get the oiler and stuff. When you say to put the hose on the bleeder and open it, is it like opening the one on a Honda fourtrax, just need a small wrench to open it a little? Also, would it work to open the bleeder and push the brake down, then before releasing the brake, close it, and do that a couple times. I did it that way on my Honda.

 

The bleeder is just like what you would see on a car- I believe its a 1/4". You can't do a conventional bleed on that brake because of the design of the master cylinder- there is a small air pocket that gets trapped in it giving you poor brake feel and stopping power. The only way to get it out is to back bleed it like I described.

 

Ok, I'll give it a shot, thanks alot.

 

Today I bought the oiler, hose and brake fluid. I went to do it and I don't see a bleeder on the brakes anywhere. It should have like a nipple on it and have a nut shape on it to loosen it with a wrench, right? All I see is where the brake line goes into the caliper, I don't see any nipple. Another question is, I see the rear has 2 brake lines, one going to each caliper. I see the one goes to the rear master cyl. and I assume the other goes to the front so the hand brake must also work the rear brake, am I right? And if so, then I should only have to worry about the caliper going to the rear cyl., right? Since the hand brake works the rear also, would you assume that the rear brake should be working ok with the hand brake? Sorry so many questions in one post.

 

Ok, I'm a moron. After my last message, I went back out and was laying under it looking, again, and thought to myself, don't tell my they put it in front where it's easy to get to. And guess what, there it was. So, now I'm going to try and git er done.

 

It seems that the oiler doesn't have enough pressure to do this, when I squeeze the trigger nothing really comes out and the cylinder doesn't get any fuller. Any ideas?