Jimm 12/28/2012Need more information - what is meant by..'they go out...'? Does this mean you have low pedal, no pedal pressure? Does this mean loss of brake fluid when the pedal is pressed? If there is a loss of brake fluid, then inspect the brake system for external leaks - check both the rigid line (tubing) as well as the flexible brake hoses at the brake calipers. Also, check the brake master cylinder for leaks.
Finally, and once the leaking components are replaced, be sure to properly bleed the brakes. Use the 'How-To-Guides' feature on the AutoMD website for the specific steps.
Check on-line for the many parts supply sources, such as; www.autopartswarehouse.com or www.rockauto.com for the replacement parts.