JP250

I have an 08 is250 AWD w/ 123k miles and recently the brake pedal has been very hard to press these past few days. Every time i would initially start it, the brake pedal would barely go down at all before i press the push start button. When i am driving, it is very difficult to come to a stop. I would have to press the brake pedal very very hard. Just recently the "Brake" warning light came on as well as the "Check VSC" light, but the "brake" warning light would come on and off as i am driving.

When i put the car in park, i was playing around with the brake pedal. When I would press the brake pedal, it is very very stiff. But then after a second of me still pressing the pedal, the pedal goes down like it normally would. I also hear a lot of air noise as the pedal is going down too if i continuously pump the brakes. When the brake pedal is all the way down, i also sometimes hear a slight high pitched whining/electronic sound coming from the pedals.

Can anybody figure out what is going on with the car? i took it to a local firestone, and they said that they think its a computer issue and that it is recommended to take it to the dealership.

robtwo

Are you current on your brake fluid changes?

JP250

It has been a while. Do you think a brake flush might help?

robtwo

A flush is where you start....

mike33

iTrader: (1)

Its probably your brake booster or vacuum valve...

JP250

yeah i was thinking it was the brake booster too. Does it seem weird that this part has failed? I've never heard of this part before. do brake boosters often get replaced on other cars too?

JP250

would this also have anything to do with the electronics of the car? I took it to firestone and they said they think it was the computer on the car. im not sure if they are right

Gville350

iTrader: (10)

If you pump the brakes with the car off, of course it will be tough to press thereafter. But the problem with it getting HARD being driving is not at all normal. Time to start narrowing down the issue. Check brake pads; if good, move onto the calipers. If calipers all operate as they should, then proceed with a brake fluid flush. If no help there, check to see if the booster is bad (I'd have no clue on how to check that unfortuantely).

JP250

i was pumping the brakes in park while the car was still on, and the pedal was still very stiff. The brake pads are still thick, but even if the pads were thin, it would not cause the pedal to be super stiff. id understand if it wouldn't stop the car quickly, but the brake pedal shouldn't be this stiff.