Two problems related to brake differential proportional valve have been reported for the 1999 GMC Suburban. The most recently reported issues are listed below.
I've had this vehicle in for brake repairs at least 6 times since I bought it. It now has 26,500 miles. The brakes have been replaced 4 times, master cylinder replaced, proportioning valve replaced, and right side caliper replaced. I have also had the following replaced: motor pulley, a/c compressor, tie rod, idler arm, pitman arm, coil in steering column, main belt, front differential gasket. Every time I take it in to the dealer, it seems that I am a pest. . . . . . . . I will never own another GMC product, and I am seeking legal advice for a possible manufacturer buyback.
On 4 separate occassions consumer has had to take vehicle in for excessive grinding noise from rear brakes when coming to a stop, also there was leaking proportioning valve that caused premature wear to rear brakes.