Q&A

The brake warning light comes on when the brake fluid level in the brake fluid resiviour drops below a safe level. the brake master cylinder is attached to the brake pedal. Pressure is generated in the brake master cylinder proportional to the force you apply to the brake pedal. This pressure goes to each corner of the car via a metal brake line and goes out to the wheel through a flexible rubber brake hose. You don't say which metal line is in need of replacement but depending on location they can be difficult to replace. The brake hydraulic system should not "loose". It may drop a little as brake pads wear but if indeed a metal line is failing this could rupture and cause a sudden loss of a lot of brake fluid.

Have you been adding brake fluid at all? My guess is no, which is why you're holding off on the repair. When was your last brake job? The reason I ask is Honda, in their infinite wisdom, engineered the master cylinder reservoir to show a low fluid/ brake light when the pads were worn, before you started grinding metal parts. It starts intermittently, especially after a good hard brake. Just a quick flash here and there. As time goes on, it will stay on longer and longer, until it stays on for good until you refill the master or put on new pads. At least, that has been my experience. Hope that helps. Look at your pads.