I got on this site looking for a schmetic for a 2000GMC 4X4 Sonoma. My problem was the Air Controls and front axle failed at the same time.I immediately assumed a vacuum failure. Your pictures helped a great deal.I found that the vacuum line was hanging loose at the driver side fender.I plugged it and they are working. According to the pictures posted it should be plugged into the fender. You can see it was attached somewhere. The top threee photos in this post illustrate it greatly. The middle picture depicts the linedirectly under the thumb.I will be darn if I can find the connection.
Sunday, October 16th, 2011 AT 9:44 PM