CriticalCommonBrakes

Chevrolet Silverado: Corroded steel brake lines along the chassis rail (GMT800)

Corroded steel brake lines along the chassis rail (GMT800) is a common brakes fault on the Chevrolet Silverado on the 1999–2006 cars, and we rate it critical. Putting it right costs $600 to $1,800 at New Zealand independent workshop rates. Below is what goes wrong, the symptoms to notice on a test drive, where to look, and what to ask the seller before you hand over any money. It is one of 14 documented faults on the Chevrolet Silverado.

Vehicle: Chevrolet Silverado
Years: 1999–2006
System: Brakes

This page covers the Chevrolet Silverado as a model. Some faults only affect particular engines or build years — enter a plate below to narrow the list to one car.

All Chevrolet Silverado faults14 documented faults on this model

What you are looking at

No photograph available

We do not hold a verified photograph of the Chassis and structural rust yet. We would rather show none than show a picture of a different part.

What goes wrong

The uncoated steel brake lines that run along the frame rail and over the fuel tank on GMT800 trucks corrode and can burst without warning, leaving the pedal on the floor. NHTSA investigation EA11-001 covered about 2 million 1999-2003 GM pickups and SUVs after more than 2,500 complaints; it closed in 2015 without a recall, finding the corrosion typical of trucks from road-salt regions, and advised owners to have lines inspected. Many NZ/AU Silverados are US imports that spent years on salted roads, so the lines may already be thin even if the truck now lives somewhere mild. Replacing the full set of lines is a routine but fiddly job.

What you would notice

Brake pedal suddenly sinks or goes to the floor
Wet patch or brake fluid drips on the inside of a wheel or along the frame
Brake fluid reservoir level dropping
Brake warning light on

How to check it

Where to look. Steel brake lines along the driver's-side chassis rail, above the fuel tank and across the rear axle

Crouch beside the driver's side and shine a phone torch along the inside of the chassis rail between the front and rear wheels: the brake lines run there, and heavy flaking, swelling or wet fluid on them is a warning sign. Look at the brake fluid reservoir level under the bonnet and for any damp patches under where the truck was parked. With the engine running, press the brake pedal firmly and hold it for 30 seconds; it should stay high and hard, not slowly sink. Ask whether the truck came from the US and whether any brake lines have been replaced, and look for shiny new or copper-nickel lines as evidence. If a workshop inspection is possible: on a hoist, have the full length of every line checked, especially above the fuel tank and at the rear axle, and have any flaking section scraped to judge remaining wall thickness.

Parts involved: Chassis and structural rust.

What it costs to put right

$600 to $1,800 at New Zealand independent workshop rates. That is for this job on its own, not for the car.

An estimate, in NZD, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

Ask the seller

“Was this truck imported from the US or Canada, and which state?”
“Have the brake lines ever been replaced, and were they all done or just one section?”
“Has the brake pedal ever gone soft?”

Now check the Chevrolet Silverado you are actually looking at

Everything above is true of the model, and it is free. What it does not tell you is whether THIS car has been looked after: its odometer history and whether the reading has ever gone backwards, whether there is still money owing on it, whether it has been reported stolen, how many owners it has had and what it is really worth today. That comes from the official records for that plate. Enter the plate for the free details, or get the full history and a market valuation from $13.49.

Not sure what you would be paying for? See what a full KickTyres check includes.

Where this comes from

The failure described above is documented in the sources below. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them.

NHTSA Engineering Analysis EA11-001 closing report (1999-2003 GM C/K trucks brake line corrosion)
ConsumerAffairs 'Feds end GM brake-line rust probe, advise owners to wash underneath their cars and trucks' (2015)
MotorWeek 'NHTSA Warns of Corrosion on Brakes'

Chevrolet Silverado buyer questions

Is corroded steel brake lines along the chassis rail (gmt800) serious on a Chevrolet Silverado?

We rate it critical and common on the Chevrolet Silverado. The uncoated steel brake lines that run along the frame rail and over the fuel tank on GMT800 trucks corrode and can burst without warning, leaving the pedal on the floor. NHTSA investigation EA11-001 covered about 2 million 1999-2003 GM pickups and SUVs after more than 2,500 complaints; it closed in 2015 without a recall, finding the corrosion typical of trucks from road-salt regions, and advised owners to have lines inspected. Many NZ/AU Silverados are US imports that spent years on salted roads, so the lines may already be thin even if the truck now lives somewhere mild. Replacing the full set of lines is a routine but fiddly job.

How much does it cost to fix on a Chevrolet Silverado?

$600 to $1,800 at New Zealand independent workshop rates. That figure is for this job on its own. A car showing the symptoms on this page is usually worth either walking away from or negotiating down by at least the repair figure.

Which Chevrolet Silverado years are affected?

Our research records this fault on the 1999–2006 Chevrolet Silverado. Build dates move around, especially on imported cars, so treat the range as the years to look hardest at rather than a guarantee either way. The official records tell you the exact build and first registration date for the car in front of you.