Faulty brakes on Astra?

I drove my car down steep hill this morning. When I went to brake. they wouldn't work. I pressed the brake 3-4 times and each time it felt like I was pushing down on air and the car jumped a little. The brakes did eventually work.
I checked the brake fluid and it's fine and we drove the car to test it and it's now fine again but I'm wary. Does anyone have an explanation for this? I'm certain my foot was on the brake and not the clutch or accelerator but I can't figure out why it would have happened.

Does sound like there could be an air bubble in the brake fluid. Could just have been that the brakes were cold, then worked after they warmed up. Did you wash the car the day before or had any recent work done to it?

It was washed a week ago and has been serviced about 4-6 weeks ago. This included new brake pads and brake fluid. I do find the brakes make a slight noise now when I press them which sounds like air been pushed out.

In my experience, sometimes if a car is stitting for a while rust builds up on the disc and you need to brake hard to give them a clean. Otherwise they'll be soft the first time you use them. Something else that can happen is on a very wet road with standing water, water can build up between disc and pad and you'd need to pump the brake to brake the water layer. I've only had that happen to me once though.

Air bubbles I don't have experience of.

well its strange that it has only just happened. I had a similar service to my brakes about a month ago, and had a similar problem which turned out to be air in the fluid, which has stopped now. If this was the case with yours it would have been there ever since the service.

I think it might be air so as the noise is there since the service. I'll get it checked, thanks.

Yeah I'd get the people who serviced it to check it and test it throughly.

Could it be the engine cut out, the brake system needs the engine running to work correctly.