Heres the deal, I bought the car and minimal brake work had been done in years, so it wa sno surprise to me that the brake pedal when pushed felt soft at first and then went hard as a rock without really stopping the vehicle. My initial thought was vacuum leak at the brake booster, so I popped the cover and inspected the lines, everything looks top notch on the drivers half of the engine. So it gets dark and I decide to close it up for the night, but not before I suction about 250 ml of old fluid from the resevoir and put new stuff in. The next morning start the car and back it out of the driveway and the brakes work flawlessly, I figure I have the problem solved, but it seems as the car warms up to operating temperature the brakes revert to their old selves again and not wanting to operate normally.

What could be my problem here? It really does feel like the brake booster is not operating properly when the car gets warm, but when the car is cold it operates just fine, now this doesnt make sense to me because this is a vacuum operated device and should have nothing to do with the temperature of the car. Can anyone offer some insight here, thanks.

My only other thought was that maybe there was a valve in the vacuum system somewhere that stays closed when the car is cold, but as it warms up this valve opens and allows for a vacuum leak somewhere.

Please help me!

 

air in system, bleed the breaks then see how it goes

 

OK, so you figure it is just air in the system, because I am just home on lunch now and the brakes worked just great! I will get a shop to bleed them on Friday when I get the oil changed. Thanks.

 

good luck but should it fail and you have problems ill look into it

 

HAHAHA Thanks! As a matter of fact I think I will be bleeding the brakes myself, simply because there is not VW or Audi dealer in my neck of the woods and I do not trust another shop to work on a car that they are not familiar with. I have a feeling you are 100% correct though with the air in the lines, it just has that feel to it. Thanks for the quick response!

 

Alright, changed the front pads and only lost a small amount of skin and wound up with a small egg sized lump of blood from a burst vein on the back of my right hand, other than that all went well. For anyone else considering the job, all I needed was a flat blade screwdriver, a 1/2" breaker bar, a 17mm regular and deep socket also some brake clean and a helper to hold the trouble light if you do it at night like I did. A C-clamp and a pair of vise-grips will also be helpful, the C-clamp for compressing the caliper piston and the vise-grips for pulling the old brake sensor connector out of the metal clip. The job is very straight forward as any diksc brake setup usually is, and took me a total of about 1 hour and 15 minutes start to finish in the dark. Don't be intimidated by the mechanical aspect of it, and give it whirl! If you have any questions about it PM me or Email me and I will be glad to help you out.

Cheers.

Trev