Brake lights don't stay on when I press on brake pedal. I have a 1998 chevy tahoe. Can someone help?

Brake light switch is activated by brake pedal arm, above the pedal. Have you looked to see if the switch is bent, broken, out of place or disconnected from wires?

These Toyotas had daytime running lights. The headlights and the taillights turn on when you start the car. If you press the brake pedal, the rear lights (and the brake light in the rear window) should come on brighter.

I have never heard of the brake light staying on (The brighter filament in the two-filament bulb). Hope this helps.

Most brake light switches have a small nib or piston/pushrod which is depressed by the pedal when the pedal returns. Many pedals are fitted with a metal plate and sometimes a plastic bung, which connects with the brake switch's pushrod. If this pushrod isn't being pushed in when the pedal returns, then the brakes are going to stay on. Check this operation carefully and please report.

Should be on brake pedal under dash, could be brake switch is sticking or bad try pulling up on your brake pedal, if tail lights go off that's what it is, if not your switch is staying stuck in.

That sounds like a brake booster problem. The brake booster runs on engine vacuum to help make the brake pedal easier to push and easier to stop the tahoe. When a booster develops an internal leak, you can hear the vacuum escaping through the leak when you step on the brake. The engine stalls because the vacuum leak in the brake booster also causes a large vacuum leak for the engine.

To verify that this is actually the problem, go outside the vehicle with the hood open. Find the large brake fluid reservoir attached to a large round metal black (usually) canister on the driver's side of the firewall. (back of the engine compartment.) There is a large black rubber hose pushed into the top of the black canister, which is the vacuum line attached to the brake booster. Pull the rubber hose out of the grommet on the booster and stick your finger over the hose. Have someone start the tahoe. You will feel a considerable amount of vacuum pulling at your finger, and if you take your finger off the hose, the engine will stall. Also have someone step on the brakes while your finger is over the vacuum hose. If the noise is gone then you know the problem is in the brake booster.
Don't forget to re-attach the vacuum line to the brake booster. Failure to do this will result in the engine running very rough (if at all) and the brakes will require excessive effort to try to stop the tahoe.

Sounds like you have a bad multiple function turn signal switch. A couple things to try With your foot pressing on the brake pedal, Press the four way flasher button up and down, press and hold it down, pull up on it, or wiggle it. If the brake lights come on during any one of those replace the switch. With the key in the run position pull, push, the turn signal lever slightly. If the turn signal or brake lights start to work replace the switch. Let me know if none of those work, they usually do, and I'll get you some more in depth diagnostic info.

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I had this problem, and to be honest, it happened to the left side about a week later...it's the board that the bulbs plug into...it's a very common problem with this model. So popular that you can normally get the socket board off the shelf at a parts store! it's extremely simple to replace, and I replaced all the bulbs at the same time!

Probably the brake light switch. It should be located below the brake pedal close to the firewall. When you push the brake pedal down, it activates the switch. The switch can be tested with an ohm meter or multimeter. Also look for damaged or disconnected wiring. Sure hope this helped and good luck.

There is a clip that gets worn on the brake pedal that holds the switch tight to one side. It must be put on correctly or else the brake lights will come on for a split second and then go out when you push the brake pedal down further.

I have an '03 Chevy Tahoe and I had a similar problem. I discovered that there is a bare copper striking plate or tab that the medal emergency parking brake pedal touches when the emergency brake is set. It turns on the idiot brake light in the dash. It had broken off and the light stayed on all the time with the say issue of chiming whenever the vehicle is in motion. You or the dealership must replace that striker plate to fix the problem.