Hi, I have a 04 Tahoe that I use for running errands so I rarely drive it, it mostly sits. I went to drive it and the pedal went straight to the floor and the master cylinder is empty. I dont see any obvious leaks. Someone told me its likely the brake line rotted above the gas tank? Is it really possible to lose everything from 1 lost brake line or it would have to be multiple?

I was told I can get a new brake line kit for under $100 but the labor seems to be way too involved because I dont want to mess with dropping the gas tank. Anyone know how much this job should cost?

I am in the northeast btw, so def have been expposed to salt roads.

 

Even if that "someone" is a real mechanic, one needs to have this investigated and diagnosed first, a real second opinion. You could be leaking from a caliper seal (and maybe not so obvious to see), a flexible brake line, or even from the brake master cylinder into a booster or hydroboost cylinder.

I suggest to take it to an independent ASE shop for a diagnosis/estimate.

 

Hi, I had a mechanic friend look at it today in my driveway and confirmed the suspicion that the brake line is burst above the fuel tank. We filled the master cylinder with fluid and i hit the brake until you could hear air rushing and fluid coming from the frame rail from on top of the gas tank. right in the middle of the truck. He was surprised though because he said thee underbody was in such good condition, but that is because i used 3m underbody spray on it when i bought it, but that doesnt help above the gas tank.

My friend works for a big dealer so he couldnt give me a price but he said it wasnt going to be cheap. Not sure what I should do its an 04 w/ 165k miles roughly.

 

OK, good that you got a second opinion. Can your mechanic friend help you drop the tank at your home? Maybe he can flare/splice in a new piece of brake line.

SwageLok connectors (available in different metals, and in metric and standard) are excellent quality and we used those in the lab even for explosive, tiny hydrogen gas.