My two month old (for me) 940 N/A wagon has soft-feeling brakes. I have bled the system and I'm getting a nice firm pedal when the engine is off.

With the engine running, however, the pedal drops maybe 1" below the point of first resistance, making it feel soft and vague on application. Is this a vaccum servo issue?

The front calipers are Girling, the rears ATE, the servo is Bendix. Brake effort seems reasonable. It's just SOFT compared to my other cars.


Thoughts anyone?

 

That might just be the way it is.All cars are different.

 

The pedal is hard with the engine off. Soon as the engine is started and vacuum is applied to the servo (booster) the pedal drops that extra inch. It doesn't "pump up" like it would if there were air in the hydraulics.

Could an internally swollen vacuum hose or defective white check valve (on the servo) cause this type of pedal response?[sm=rolleyes.gif]

 

After you turn the car off does the pedal get hard right away.Or does it take one or 2 pumps to get hard?
If it takes one of 2 that is normal.
If there was a vaccum leak at the booster or vacum supply to the booster the pedal will be rock hard.

There might be a problem with the master cylinder.

 

have you tried having them bled?

 

With a Vacume assist hydrolic braking system your brake pedal will be hard and when you start the car it should move down about an inch, if it does not than you have a brake booster going out. A brake booster going out can also cause brake fluid to be leaking into the vacume line and cloging the check valve. Soft brakes are not bad, like Tech said, it may just be your not used to them. If your brake pedal goes all the way to the floor than your brake lines need to be bled. You may want to do this just to verify you have no air in the system. Good luck and welcome to the Volvo community, I myself have recently purchased one too.