One problem related to brake drum has been reported for the 1997 GMC Sierra 1500. The most recently reported issues are listed below.
The problem with the abs-- it take longer to stop than it would without abs, it also seems to actually slide on slippery surfaces such as ice & snow. . . . Even though pedal is held firmly down, the wheels grip, then release, as if the abs is not cyclling quick enough. I drive another gm vehicle with abs & that system works differently & works ok. I am not talking about the pumping & pressure I feel from the pedal. The wheels will slide before the abs kicks in, or so it seems. As regards to the rear drum brakes--- when it is cold & damp, the rear wheels will lock up with just the slightest pressure on the pedal. . . Once it has been driven for approx 5 miles & the brakes used & warmed up, then the problem goes away. . . . . . This is a very annoying & dangerous trait of this vehicle. . . This has almost caused an accident on several occasions. . Thank you.