Brake fluid
Could be your brake fluid. As time goes on, your brake fluid becomes contaminated and needs to be replaced. Enough water contamination and you start to lose function. If your brakes get hot enough, the old, oe fluid will actually boil - creating a bad brake situation. This is also one of those maintenance items hardly anyone ever does. Replace all the fluid with high temp racing juice. Bleed all 4 calipers at the same time.
If this doesn't help with the spongey pedal, you may have a problem with the master cylinder or the vacuum booster. Check all the vacuum lines and ports first. If you are pulling plenty of vacuum, check the master cylinder.
Depending on your mileage, you may be nearing the end of the life span for your master cylinder/booster/calipers, etc.
Could be your brake fluid. As time goes on, your brake fluid becomes contaminated and needs to be replaced. Enough water contamination and you start to lose function. If your brakes get hot enough, the old, oe fluid will actually boil - creating a bad brake situation. This is also one of those maintenance items hardly anyone ever does. Replace all the fluid with high temp racing juice. Bleed all 4 calipers at the same time.
If this doesn't help with the spongey pedal, you may have a problem with the master cylinder or the vacuum booster. Check all the vacuum lines and ports first. If you are pulling plenty of vacuum, check the master cylinder.
Depending on your mileage, you may be nearing the end of the life span for your master cylinder/booster/calipers, etc.