Having problems with your 1998 GMC Sierra ?
Brake peddle keeps goin farther down, less stopping. is it the calliper?
More than likely it's air getting into the system via a leak. If you are able to, check for a brake fluid leak at the rear brakes, brake shoes should be clean, if they are oily you have a leak.
Repair Help & Product Troubleshooting for 1998 GMC Sierra
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