Same here.
Now I keep my hand on the E-brake handle instead of the shifter when starting off from a cold start.

 

Bump.

 

Ttt

 

Sounds similar as the issue with the Pontiac Solstice.

http://www.solsticeforum.com/forum/f...d-start-50941/

 

All Turbo related.....at start up there is only -5 vac on the system,not enuf for brake boost..after a few min it drops to -20 where it is normal.At start up I reason that the turbo is slightly spooled up so vac is minimum til it settles down then starts creating real vacuum.A simple fix is a aux vac can(Summit) like those used on vehicles with large overlap cams that don't have a lot of vacumm at idle.Other wise GM needs to fix the reason why the booster does not hold vacuum over nite.Apparently its bleeding off.And I don't believe it has anything to do with auto or 5 spd as neither of these have any vacuum to them.

 

Were finding the start-up process is taking a bit longer to create enough engine Vacuum. Over 45 seconds now and this is now happening daily where as before it was every once and a while and the delay was just 15 seconds or so. It's getting worse.

We ran it by the dealer and they played dumb...never heard of it before...total BS. They had 7 SS's in stock when we bought ours. All auto's so you can't tell me nobody has complained about it and expect me to believe it.

Having the ABS modulate the brake pedal...solves what really? It's not like the ABS system builds hydraulic pressure. Your FOOT has to do this by pushing on the pedal.

GM needs to get off it ass.

 

Why is this only an issue with the autos?? Doesn't a manual have to build vacuum for the booster to work?

 

It's not only with the autos, though they seem to be affected more than manuals. It seems that a slow vacuum pressure leak is somewhere. Maybe the leak is more common on autos because it's common where some undetermined auto-only parts meet. Maybe it's just noticed less on manuals because drivers tend to be in low gear when they first start up so are often using engine braking at low-vac times. Maybe other things...

 

I've experienced it as well, but as I mentioned above, there is a very simple workaround until the problem gets fixed by GM. As for variance between stick and auto, does the auto trans need vacuum as well for the modulator (does it have one)?

 

Unfortunately, the workaround is only viable as long as every driver is able to remember it 100% of the time. Suppose someone gets injured at your house. You hop into your car to get them to the hospital ASAP, thinking about their injury, quickest route, etc, and in all the excitement you forget to warm up the vehicle. What if you are the one who normally drives the vehicle, and another family member needs to borrow the vehicle for some reason, without being explicitly told that the brakes don't work until the vacuum builds up? Suppose you remember 99% of the time to warm it up sufficiently. Who pays the price the 1% of the time when you forget, and just how much will they have to pay for how long because GM has chosen to ignore this issue for so long?