Two problems related to brake fluid leak have been reported for the 1997 GMC Sierra 1500. The most recently reported issues are listed below.
Driving downhill at 25 mph and applied brake to slow down to drive over small bridge. Brake pedal went to the floor and brake warning light illuminated. I depressed brake several times to stop and pedal went to floor without the vehicle stopping. I found brake fluid leaking from steel brake line along drivers side rear frame rail.
Brake fluid began leaking from under the driver side door. Closer inspection revealed the brake line had corroded and began to leak. This was replaced in January 2011. After replacing both front brake pads and pressing the brake pedal, the brake line on the passenger side burst and after inspecting this brake line as well, it was corroded and finally gave way due to the extra pressure exerted by the new unworn brake pad. The amount of corrosion seemed excessive for this to happen so suddenly. In both cases, the vehicle was not in motion and no harm was caused due to early recognition of the problem.