The ABS modulator (hydraulic unit) can leak air into the brake system and cause a low brake pedal. A new ABS modulator will be needed if it is diagnosed to be the source of the leak.Google+
Car Problem Reports
Honda Accord Hybrid ABS Modulator May Leak Air and Cause Low Brake Pedal
Honda Accord Hybrid Problem
Average Mileage: 80,082 mi (17,330 mi - 148,000 mi)
Visitor, 2007 Honda Accord Hybrid, 17,330 mi
Unable to stop car slowing down for stop sign. Hit car in front of me.
NO WARNING LIGHTS at all. Drove to nearest dealer the next day very, very
slowly. Service found air entering into ABS Modulator. Modulator replaced,
cost $1,400. As per service, out of warranty. Still trying to get regional
rep to fight this charge. To make matters worst, received ticket even though
modulator defective? Get the not my job feeling?
Visitor, 2005 Honda Accord Hybrid, 148,000 mi
As described above. $2200 problem plus labor.
Visitor, 2006 Honda Accord Hybrid, 32,000 mi
Brake pedal is going all the way to the floor. Brakes need to be pumped up a second time to so it doesn't go to the floor. Not yet fixed, don't have $1,000 laying around for the ABS modulator part aside from the service costs.