Intermittent Brake Failure - 2004 S60 2.5T
 

The strangest thing happened yesterday and I'm curious if anyone here has had a similar problem. I checked the search feature and didn't find anything like this.

I loaded up the family to go to a pumpkin patch last night and when backing out of the driveway I noticed that I had no "power" brakes. I had to mash on them pretty hard to get the car to finally stop. I put the car in drive to go back into the garage and noticed the same thing in that direction.

We decided to take my wifes car! When we returned I fired up the Volvo again and the brakes were just fine. It seems I had an intermittent power brake failure. The worst part is there are not warning lights or check engine status indicators going off.

I am worried that this could happen mid-drive causing a wreck. Has anyone had this problem before? What should I look into? The car has 125k miles on it now and has been fairly flawless up until this.

Thanks!

Assuming your car has vacuum assist brake booster (assuming it does but I'm not familiar with the newer models..) then that's where your problem is.

Ck the vac hose (about as thick as your thumb) going from the intake manifold to brake booster; usually hose connects to a plastic piece at the booster; this plastic piece is the check valve.

Either the the hose is collapsing or kinked, or the ck valve could be having intermittent failures. Never heard of booster themselves going bad intermittently but suppose it could happen.

If you don't see anything obvious with the booster vac hose or ck valve, then vacuum test the booster itself.