The brake lines in 1999-2007 GMT800 Silverado’s, Sierra’s, and Suburbans are very prone to rusting out and needing replacement. For individuals who live in “salt” states, where cities commonly salt the roads to prevent ice, the brake line rusting is even more common. In 2010, a class-action lawsuit was filed as rusted brake lines were leading to brake failure and causing accidents.
GMT800 Brake Line Failure
The brake lines used in all GMT800 Silverado/Sierra/Suburbans are a copper plated steel tube. The lines are then coated with an “AlGal” coating to protect them from corrosion. However, the AlGal coating, which is a form of aluminum paint, was easily damaged or worn down from normal tire kick-up. In 2007, with the GMT900 line, Chevy upgraded the brake line coating to a NyGal coating which was made of plastic and significantly thicker than the previous AlGal coating.
Corrosion can lead to break lines leaking fluid, with the end result being the brakes not working very well, or hardly at all.
Additionally, portions of the GMT800 brake lines are made of rubber. Over time through normal wear and tear, this rubber can get deformed and cause air pockets in the lines when pressed. The end result is not enough brake fluid getting to the calipers for the brakes to function properly.
Brake lines can go bad as early as 50,000 miles, or as late as 250,000 miles. If you live in a salt state, we recommend changing the brake lines approx. every 120,000 miles.
Chevy Silverado Brake Line Failure Symptoms
- Leaking brake fluid underneath vehicle
- Brake warning light illuminates
- Squeaking brakes
- Shaking, vibrating, or wobbling when braking
- Soft brake pedal, feels spongy
DIY 1999-2006 Brake Line Replacement Guide
https://chevroletforum.com/how-tos/a/chevrolet-silverado-1999-2006-how-to-replace-brake-line-392749
1999-2006 Brake Line Diagram for Silverado, Sierra, Suburban
This brake line routing diagram is applicable for:
1996-2006 Chevy Silverado 1500/2500/3500
1996-2006 GMC Sierra 1500/2500/3500
2002-2006 Cadillac Escalade
2000-2006 Chevy Tahoe 1500
2002-2006 Chevy Avalanche 1500/2500
2000-2006 Chevy Suburban 1500/2500
2000-2006 GMC Yukon 1500/2500
I have a 1999 Sierra. Every now and then, quite rare, when I push the brake pedal, I have a real hard brake, not to push down, but it stops and is like pushing against a brick wall, and it has no brakes, it just keeps rolling. Once I release the brake pedal and press the pedal again it will stop normally. Any Ideas?
your brake booster is defective
check the vacuum line coming of the rear of the intake system to the booster. This line will break down over time become weak and kink up at the rear most part of the hose whereby there will be no vacuum going to the booster resulting in a very hard pedal.
I have a 2020 silverado who’s brakes went soft and traction control cancelled. Brake fluid obviously lost and had too be towed to a dealer. Still waiting for the dealer to diagnose but I don’t have much faith in their answer as they have had it for 2 days already.
I have a 04 Silverado. Horrible passenger side front wheel shudder when braking. I have replaced pads , rotor , caliper and wheel bearing . No change. Stops fine and doesn’t pull at all. Feels like you are driving over rumble strips when braking. ???
I had a complete brake line replacement on my 2002 chevy silverado 1500.. Then my ABS locked up my brakes while i was driving. Why would this happen?
I replaced both rear pads calipers and rotors and front pads. When trying to bleed I am getting fluid from just the front drivers bleeder valve. And suggestions greatly appreciated.
Try closing off drivers bleeder and putting vacuum to the passenger side. I have had this happen and this seems to correct the issue.