Front brake lever gets spongy again two days after bleeding

Old rubber brake hoses can expand under pressure. If the hose is original, it might feel like air even after a good bleed.

Try tying the lever back overnight and tapping the line/caliper gently. If bubbles collect at the top, the lever may improve temporarily. That does not fix the source, but it confirms trapped air.

The hose is old. I also noticed the bleed nipple threads look wet during bleeding, but not afterward.

Spongy lever after bleeding: separate air, hose expansion and master cylinder bypass

Sofia, brakes are safety-critical, so treat this as a controlled inspection, not a casual experiment. A lever that becomes spongy again can come from trapped air, deteriorated hose, a poor bleed technique, or internal seal bypass.

Suggested checks:

1. Inspect the hose date and condition. If the rubber line is old, cracked, swollen or very soft under pressure, replace it. A braided line is not mandatory, but a healthy approved hose is mandatory.
2. Bleed with the caliper positioned correctly. Air rises. If the bleed nipple is not the highest point in the caliper cavity, remove the caliper, place a spacer between pads, and orient it so bubbles can escape.
3. Use grease around bleed nipple threads during bleeding. Wet threads can pull air around the threads when using a vacuum bleeder. That makes you think air remains in the system. Grease on the threads, not inside the hydraulic path, helps seal the outside during bleeding.
4. Clamp test carefully. With a proper brake hose clamp, isolate the hose/caliper side. If the lever becomes rock solid, the issue is downstream. If it remains spongy, suspect the master cylinder or trapped air near the top.
5. Check caliper piston movement. Sticky pistons can retract unevenly and increase lever travel.

If you are unsure, have the brake inspected by a qualified mechanic before riding. The course platform includes a free braking-system module, and I strongly suggest enrolling and watching it before doing more hydraulic work. Understanding the system is part of staying safe, not only fixing the bike.