My front brakes come on when they want to!

Do you bleed the brakes once or twice a year?

If that does not help, try a German master cylinder with new brake light switches.

It wouldn't be too costly to replace the flex. rubber hose running to that wheel. they sometimes swell up inside, causing the brake to not release. good luck

I was thinking about my brake problem as soon as I woke up this morning. I want to emphasize, that the brakes would come on without me pushing on the brake. I did not think it was the master cylinder as how could the master cylinder "put on the brakes" strongly without me pushing on the brake pedal.

What I did this morning was to open up the bleeder bolts ( there are 2 / caliper). When I did I noticed there was about a 4 second pause until the fluid began to flow out. I thought this is strange. My thoughts are this? what pulls the caliper piston back in ( away from the rotor) when the brake pedal is no longer being pushed? There are no springs..............

It is the fluid being "sucked back in" (so to speak) toward the master cylinder. If there is no fluid by the piston, it really is not efficently being pulled away from the rotor.

So what I think was happening was my brake pads were never sufficently being pulled away from the rotor ( I noticed my car would not roll as easily on slight grades in neutral from a dead stop like it used to) so they were rubbing harder than usual on the rotor.

This gets things real hot, this heat expanded both the air gap and fluid just enough push on the brakes harder, which made it hotter, which expanded the air gap and liquid more, which put the brakes on more...continuing the cycle. ( there were times I was really pushing the engine hard just to keep the car moving, letting off the gas, the car would come to a quick stop, pulling on one side). One or the other front rim was incredibly hot, withthe smell of buring brakes - all without me ever pushing on the brake pedal!)

After removing the air gap, I noticed my car was rolling very easy in neutral on slight grades from a standstill.

It gave me no problems today, but I will not feel confidient for about

2 weeks.

If what I did does not work, I'll post back. If it does work, I'lpost back still

Hope it works!

And thanks for all of your replies, and help.

Matt S.

Crusader george wrote:

The pistons in the caliper are not pulled back when you release the pedal. They merely float in the last position when the pressure in the line returns to zero. This enables the pad to remain against the rotor ready for the next deployment without creating any pressure/friction on the rotor. When you released the air you effectively reduced the pressure in the line to zero and allowed the piston to shift position. I would look for warped rotors, swollen rubber hoses, malfunctioning partition valves or a faulty master cylinder. Check the endplay on brake pedal at the master as well. If the master is not allowed to return to the off position it will hold pressure in the line and cause your problem. As a side note check and repack the wheel bearing. All that heat will cause the grease to run.

This measurement is very important. There is a check valve in the MC that allows the fluid back past the piston (in the MC) to the resevoir. There should be a 1mm gap between the pushrod on the brake pedal, and the cup inside the rubber boot. This translates into a 5-7mm gap at the top of the pedal. Lightly press the pedal with your hand and you should be able to feel when the rod touches the cup. The adjustment is made via the stop that's bolted to the floor in front of the brake and clutch pedal. DO NOT ADJUST THE PUSHROD ITSELF. It's common for this gap to change if the MC is ever changed, or if the carpet ends up being wedged up in there. After adjusting the gap, you'll need to readjust the clutch, as the stop sets the clutch pedal height as well.

Someone else mentioned the rubber flex lines. Even though they might look perfect on the outside, it is possible they're swollen or deteriorating on the inside. This will not allow the fluid to come back.

the fluid is not "sucked" back in...the line pressure is released...the pads do not get pulled back, only slightly pushed away by the rotor....they should, and do, remain in slight contact with the rotor....

Please pay a professional. Brakes are very important. Other than lug nuts, they may just be the most important item on your vehicle. I'd hate for you to smash into my VW. Who cares about lives, when VW's are at sake here.

My first question was if you bled the brakes, but several jumped on that subject allready. I don't have an answer.. sorry.

Matt S wrote: