About a month ago I had my paniced girlfriend on the phone saying the brakes had failed on our 2003 Mk4 TDI.
So I cycled over to take a look and everything seemed fine and no problem evident and was able to drive the car away.
She complained that the brake pedal went really hard and could not provide any braking.
Obviously quite scary, so I took it to a mechanic friend the next day, who said it could be a servo valve but suggested it could have been a once in a lifetime event and to do nothing, but keep an eye on it.
Been using the car regularly (as you can in Lockdown!) and no problem.
Today the brakes failed again as previously described before. Very hard brake pedal and probably only 5-10% of braking action, so very very dangerous.
Luckily I was on a quiet road, so no imminent danger ( ) However after eventually stopping I tried to move away and try the brakes again and they were still not working.
I then parked up, switched off engine and left it for 20 minutes. When I restarted the car and tried the brakes again everything was fine, no problem. All working normally.
What could be causing this problem? I'm slightly scared to use the car again.
Please note that on both days of failure it was very wet, including travelling through big puddles on country roads. Could the water in the brake system somehow causing this issue?
Has anyone else had something simliar?
I looked on other forum posts, (namely https://uk-mkivs.net...o-stop-the-car/ & https://uk-mkivs.net/topic/237835-braking-stiff-vacuum-line-issue-2001-19-tdi-solved/ ), but both these issues were not random events like mine and did not cure themselves.
Any help / suggestion much appreciated.