This started last week, noticed it once, then again a few days later. Since then it's happened more and more often. And now does it maybe 40% of the time you push the brake pedal.

What happens is the travel on the pedal is massively increased. i.e. you might brake and the pedal will feel normal and firm. Then when you brake next time the pedal will have 2 or 3 times the travel.

It doesn't feel soft and the brakes still work, just with a massive amount of pedal travel that doesn't do anything.

When this happens is you pump the pedal once, i.e. come up off it and back down and you get a firm pedal again.

I'm guessing it must be vacuum or servo related, but wondered if there were any common traits or causes for it.

It doesn't do this everytime, but it has progressively got worse over the last 7 days. So something must be deteriorating. And I don't think it's mechanical or fluid related, as it's too inconsistent.

Car is a '99 Turbo UK.

 

HI
It could be a wheel bearing on its way out , this will cause pad knock off , check for play by jacking the car up , grab the wheel top and bottom and see if there's any play.

Also could be a pad getting stuck in the calipers , jams up causing pedal problems , then moves putting the pedal feel normal again.

Or it could be a master cylinder playing up , maybe just needs a bleed , how long ago were the brakes bled ?

Hope this helps
Cheers Ian

 

Thanks for the tips. Not sure when the brakes were bled last tbh, they probably need doing.