Spongy brakes

[Z71]

I replaced a leaky brake light switch on my deuce several months ago. This is an old style switch actuated by pressurized brake fluid, not by pressurized air. Then I bled the system and the brakes were good and the pedal firm for a while. Then I noticed that the pedal became gradually more spongy and now I hear hissing noise when I pump the brake pedal several times. It becomes more firm as I pump it. I wonder if I somehow have some air trapped in the system or is the air pack going bad? I would assume it is only trapped air, as this hissing noise is the same I heard when the brake light switch failed and brake fluid was leaking out.

Should I try to bleed the brakes again? That DOT 5 fluid is awfully expensive at $ 27/quart.

 

[Flyingvan911]

Might be air in the system still. Might be a good idea to bleed it again.

 

[rrrr]

Check your fluid level as well.

 

[stampy]

Air in the system.

 

[Z71]

The fluid level is OK and I see no evidence of any fluid leaking anywhere. I will have to bleed the brakes again. First I will bleed the air pack, then one wheel at a time.

 

[RAYZER]

I would bleed the system again, put a clear piece of tube on the end of the bleeder and catch the fluid in a container, you can strain and reuse the brake fluid as long as its clean.