Today I found that the braking performance is very bad on my recently acquired 1998 V70. I bought the car 6 months ago from the original owner. It has about 100K miles and the brakes were fine with excellent stopping power, short pedal travel and very solid pedal feel.

For the past 4 months the car sat outside and was not driven. I last started it in February and just drove a couple of miles, I think the brakes were OK then. The battery completely discharged in the past 7 weeks. Today I charged the battery and went for a drive. The first thing I noticed was that the brakes felt very different.

Now the brakes start to engage like they always did after short pedal travel but then the pedal sinks much further than normal and there is little ultimate stopping power. I tried a panic stop on asphalt - ABS does not engage and the car does not stop fast. I tried a panic stop on loose gravel - ABS did operate then.

I am guessing that leaving the car outside in 10-40 degree snowy weather and not driven for several months did something to the braking system. Perhaps some rust occurred in the master cylinder and seals were damaged ? Or perhaps a rubber brake hose has weakened ?

Master cylinder fluid level is normal and brake warning light stays off.

Thanks for any advice,

Mike