My Opel GT has the common problem with the cold brakes !
as most of you know, when you leave the car 5-6 hours or more stopped, when you are trying to aply the brakes, they make ''bubles'' as the pedal goes down and they hardly applying power to stop the car! this happens for the first km

I've taken the car to several GM-Opel Dealers in order to be fixed, but no one had managed to fix it!

After searching in the TECH2 i found ->


Please tell me if yours had been fixed and how
Am desperate please help

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the air boost is low at start, i heard they do have a reprograming that helps this issue.

For me i have no issue with this as I always warm any car up before driving a cold start motor. The sol will be at full vacum in a minute or so from start. Funny things is i have found even if not warmed up the brakes although a bit harder to depress still function. We live on a very steep hill. So backing out if the brakes did not work i would end up in the peoples house across the street. Even with no warm up i can stop it still. Then again i have drove many a non power barkes car in my days so its something i am used too.

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2008 GXP
Auto, Air, Mud Gaurds
1971 z28
open chambered large D port .30 over BB
Six speed ROD
cold air hood
Eaton posi 12 bolt
44gallon Fuel Tank

I received my car after the "fix" was released so I assume that I have it. My pedal seems fairly soft before the vacuum booster is recharged and runs into ABS mode, if I don't let it warm up, not very often. Another thing you can do is rev the engine up a couple of times before you leave in the morning. Both of these will provide the booster with vacuum so the brake will feel normal.

This is a common issue for all DI engines and if it has a turbo, it's a bit worse. For some more information, you might want to check out: Automotive Engineering International Online: Tech Briefs, April 2000, Page 1

It's fairly basic and is a advertisement in the guise of a tech article but is factually sound.

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Delivered!

Deep GXP.

Does this even have a top?

This is not a good assumption. I also bought after "fix" which had not been applied. After having the fix applied the "cold" brakes are better. The fix seems to have made the "brakes" a bit better overall. I am generaly underwhelmed by the "brakes" in general.
The brakes for a performance car are not up to par. My wifes Jeep GC stops better.

Be that as it may, I still have no issues...

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...not really a need to warm up a car made in the 21st Century except for personal comfort. Many people think it 'helps' their car's life to warm it up; hey it's your car. But it also shouldn't take a minute to get 'full' vacuum. Drive it any way you want, I'm not telling you what to do and it's your car not mine

I don't understand the brake issue at all. I've never read a really good description of it. What I read from GM was that at low rpm there's a vacuum issue, but the car should be making maximum vacuum then

If the car has vacuum issues for brakes, a vacuum accumulator was always the answer back in the day. Big cam, low vacuum? Get an accumulator. Why this ancient technology was passed over in favor of a system that obviously does not satisfy the owners is beyond me

Truth be told, I decided I was buying an '07 GXP because I didn't like what I was hearing about the brakes in the '08s

Read the description in the link I posted in post #3. It explains why there is low vacuum on start up with DI engine. A turbo only adds to this issue. The '07s had an auxillary vacuum pump to combat this. Like anything else, it's expensive and GM was told it didn't need the vacuum pump if it took advantage of the ESC system that's already there and save $$, weight, and accessory drag in the process. From what I've heard *warning- rumor* the '09s will have a vacuum pump again.

It's always good to have things operating in their perferred environment before stressing them...

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Deep GXP.

Does this even have a top?