Brake pedal went to floor!

[Michael Haas]

Yesterday purchased a 2008 VP with only 26,000 miles, bumper-to-bumper warranty for 18 months/22,000 miles. Test drove no issues. Drove it 100 miles from Indy to Louisville. Almost got home and suddenly with no warning brake pedal went to floor at stop light! Pumped brake pedal once and car barely stopped while making a grinding noise. After going through green light, pulled over and turned engine off. Brake pedal is more soft (spongy) than previously owned 2005 Pilot. Took to dealer today. Braked fine on way over there. What can cause such an intermittent brake issue? Scared to keep a car that exhibits a brake problem like that completely out of the blue!
Will know what dealer says tomorrow afternoon. But I am considering taking vehicle back if they say they can't find a problem.

[cofetym]

Air in the lines probably.

[sand wedge]

My old Nissan Xterra had the same issue. Went to the floor one night and was fine the next day. Turned out to be the master cylinder.

[Michael Haas]

dealer found nothing wrong. I questioned them about air in the lines, especially since the brake pedal is so spongy. I tested another Pilot at the dealer, and it had spongy brakes too.

My wife told me in greater detail what happened. On 2nd time she pushed down hard on the brakes, she was barely rolling but yet the Pilot continued rolling toward the stopped car in front of her. She said it made a sound only when pushing on the brakes. Like "whirring" or "hydraulic pump" sound. Today I drove it home with no problems other than still spongy pedal. Any further thoughts? Thanks for your opinions.

[LChisum]

Don't know what the road conditions are in Louisville, but could it be slick streets and your antilock braking system kicking in?

Larry

[rocky]

When the ABS kicks in, there is a pulsing feel and noise. The natural reaction is to lift off the brakes.

Do the opposite PRESS HARDER. Let the ABS and brakes do what they are designed to do.

Either the road was slick or your wife wasn't paying enough attention and had to do an emergency stop.

[DannyP]

x2 to rocky
Michael's story sounds like his car was engaging ABS at that time. cause he mentioned 'grinding noise' and it is typical noise from ABS system. It should happen anytime when tires gets 'locked' and slips from the surface of the road while applying brakes. you should Press harder on brake pedal to stop the vehicle.

[Michael Haas]

well I certainly appreciate all the advice. Roads are completely clear in Louisville (thank goodness!) We have owned 3 or 4 cars with ABS and I probably shouldn't have used the "grinding" term. She told me it was more of a "surge" sound. There was no pedal pulsation that happens when ABS is kicking in. I know it seems like I'm changing the story, but I think it's more evidence of a husband who is not a good listener. (you're all guilty too)

She said the 2nd time she pushed down she was pushing as hard as she could, and it was as if she couldn't override the car's wanting to creep forward (but she was not going more than 2 miles per hour). Like the brakes really just didn't want to grab hold and stop. And of course she was standing on the pedal. I'm still afraid it's the first sign of a master cylinder going bad, and it showed up after driving for 2 hours at highway speed.

[Skoorbmax]

I think it's more evidence of a husband who is not a good listener. (you're all guilty too)

Don't I know it.

When ABS would engage on my 2000 Maxima it would have the "grinding" and pulsing (common in ABS) and then once the ABS had stopped there would be almost a metallic "ping" sound.

Still, sponginess aside (highly subjective and may not be a problem on this vehicle), if conditions were dry and the brakes felt like they weren't working I'd have to say continue to pursue this. There are tests to confirm master functionality or brake booster, but I'm sure the dealer tried this. Otherwise, perhaps bleed the brakes. At the very least make sure you know exactly how to drop the gears and hit the emergency brake if the primary fails. If you can borrow from dealer another 2008 and compare them yourself it would be helpful. If nothing else play up how you just bought this thing and if the brakes fail and cause a major accident after you've already brought it into the dealer "it's going to look extremely bad". No need to get threatening a lawsuit or anything, but... I'd just be sure they take it seriously.

[Michael Haas]

Thanks Skoorbmax! Your answer was thoughtful and insightful.

I have learned now that at 26,000 miles dealer added brake fluid, but pads front and back are still original. Questions about this:

1- Is it normal to require adding brake fluid to a 26,000 mile car when no brake pads have been replaced yet?

2- Is it possible that if the brake fluid was low while driving, that it could have induced air into the lines?

3- After this braking incident, Pilot has been driven without issue. Is it possible that if air was issue, that it would have "fixed" itself when this incident occurred?

[rocky]

1: As pads wear, the level of brake fluid in the reservoir will drop to accommodate the loss of pad thickness-but rarely enough to require topping up. Red flag?
2: No
3: No