How can the brakes fail without warning and then work just fine after a 30-minute ride on a flatbed tow truck?

I drove my housemate's 95 Accord wagon yesterday about 20 miles and it was fine. Stopped at a light on a downhill incline in town and it was fine. Light turned green, we all started to move, and about 50 yards later, traffic slowed down. I was coasting on a flat area of road, foot off the gas, maybe 3 mph. Trash truck in front of me applied the brakes. I applied my brakes about 10' from rear of the trash truck but NOTHING HAPPENED. The brake went right to the floor and there was no brake! I thought I might just coast to a stop or maybe bump the truck's fender, as I was only going about 2-3 mph.

The Accord did bump the trash truck's rear and it buckled the Accord's hood, but there was no damage to trash truck. The hit was so mild that the trash driver got out, came back, and said, "Did you bump me? Oh, I guess you did!"

I paid $150+ to have AAA tow the car home per housemate's preference. He then drove the car down the driveway AND THE BRAKES WORKED FINE. Naturally he thinks I'm lying about the brake failure, but I know the brakes failed. I'm 59 and have driven for 40 yrs without causing an accident. I wasn't texting or otherwise distracted. There simply were no brakes.

Again, how is it possible for the brakes to fail one minute, and then work perfectly fine after a 30-minute ride on a flatbed truck?

PS: There were no brake sounds like when brake pads need replaced, it was a sunny day on dry pavement, and I just barely moving.

Also, I'd appreciate your opinion: Should I pay to replace his hood?
I appreciate the loan of the car, but I was not irresponsible in my use of it. Housemate says since I was driving it's my responsibility to replace the hood at an estimated cost of $2000. I want to be fair, but hey, I could've been killed or killed someone else had this happened at a higher speed AND I'm already going to end up with a fine for hitting a city truck...

I called my mechanic who offered to inspect the problem without fee to me if housemate drives it over. What items should I make sure the mechanic looks at?

Thanks for your input,
Anne

 

Sounds like the master cylinder is going bad. Is the brake fluid clean and not dirty looking? If the brake fluid gets dirty it can eat the seals in the system away.

 

Lazlong, how do I check brake fluid? Car sitting in driveway; housemate still sleeping; might be a good time for me to do this. He bought the car last October, 2011 and told me he had replaced the master cylinder. No offense to him but he's tough to talk to, very blaming type personality so I'm not getting much conversation here other than demands to replace the hood. Should I?

 

You were driving, you are responsible. Apologize and get a recycled hood.

 

If it was me I would tell him to wait and have it checked before you buy a new hood. If the brakes are going bad you shouldn't have to buy one. If they can't find anything wrong with it then buy him a $100 salvage hood and chalk it up to a lesson learned.

Nationwide salvage listings: http://www.car-part.com/

Open the brake fluid reservoir and dip your finger in the fluid. Is it gritty feeling or look dirty?

 

The master cylinder isn't going bad. It is bad.

Even if you had a leak in one of the lines, the other lines, since they are separate, would have allowed you to stop. You just would be losing fluid.

 

I have the same problem with a 2001 Honda Accord. In July I went to stop by the house and drove into the hedge instead. I thought it was my inattention. Got the damage fixed last week. Then on Friday I drove into the hedge again. I checked my feet and I had the clutch and brake pedals fully depressed. I also noticed the engine racing. So now I think it is an intermittant electronic problem. On both occasions I was doing about 5mph. But if the garage find nothing wrong then I think I need to persuade my insurance company that it is a write-off. I am not sure if they will agree to this ...