I have a 95' scrambler 400 4x4 and the back break pedal does not work. The back break will work with the hand break. I've turned the screw in the center both ways but nothing works. Can you help?

 

Well, start off witht the easiest and cheapest things first. Check the rear resevior to see if it's filled to spec. The next thing to do would be to bleed the brakes. There are two bleeder screws on the caliper. One for the foot brake, one for the hand brake. Try bleeding the line first. If that doesn't work then my guess would be that the rear master cylinder needs to be replaced.

 

I looked at the calipar for a bleeder screw but could not find one. It looks like the rear brake pedal is a manual brake. There has got to be a trick or some thing. Need more imformation.

 

Your bike has the same rear brake system(old version) that my xplorer has. It is a fluid and manual brake system on the rear. The bleeder is on the top of the caliper but the fluid part of the system has nothing to do with the foot pedal. Most or all are set from the factory to a 60:40 split with the 60% to the front calipers. I would check the brake pads and rotor first, make sure nothing is binding up the rod that goes to the pedal and caliper, make sure the nut is tight and yes, to increase pressure you screw the bolt in. There are two bolts that hold the outer housing of the manual section in place - i would check them or take that assembly off to check it - sometime the manual part inside will break - therefor fluid system still works. you can see a diagram of the rear brake assembly at ronnies.com.
hope this helps
hunt