Four problems related to brake hoses, lines/piping, and fittings have been reported for the 1999 GMC Suburban. The most recently reported issues are listed below.
Complete loss of brakes coming up to a stoplight in moderate traffic. Widespread heavy corrosion/deterioration of brake lines resulted in rupture of brake line over left rear wheel. Emergency/park brake used to avoid accident. Clearly a materials defect in the brake system, in my opinion.
While attempting to stop in a business parking lot, brake pedal unexpectedly went to floor, vehicle ran over curb/stop, damaging suspension. Cause of incident was determined to be a ruptured metal brake line, caused by severe corrosion. A second line was found to have small pin hole, which had not yet ruptured, but could have failed at anytime.
Brake lines rusting through; lost rear brakes first time (early 2008) and I had 2 brake lines manufactured that were of higher quality than original; this time lost front brakes - metal line started leaking rapidly; now have to replace all remaining brake lines to feel safe. Suburban 2500.
The right rear transmission seal broke twice and leaked fluid onto the rear brake. This resulted in loss of braking ability. The positive battery terminal leaked acid and caused the battery tray to rust.