No brakes in the morning. It will definitely wake you up more than coffee.

[WyrTwister]

I do not own an AVEO , our car is a Sonic . So I do not know how much they have changed . But I will take a look when I get home .

It may be in the brake booster it self ? Where does that hose connect to the engine to get the source for its vacuum ? Can you take a photo & post it ?

In the mean time , you might try the following test . Un-hook the hose at the source . Suck on the end of the hose , as hard as you can . Then try to put your thumb over the end of the hose , to hold the vacuum . Then release your thumb . Did it loose all the vacuum ? Or hold that inside the booster ?

I am wondering if what ever fitting that the end of the hose attaches to , at the engine , may have a check valve inside the fitting ?

I looked at photos of the booster , on line . The fitting at the booster appears to have no check valve at that point ?

This check valve appears to be a " universal part , and not specific for your car .

Dorman HELP 80189 - Power Brake Check Valve And Grommet | O'Reilly Auto Parts

God bless
Wyr

[jamesd]

Here are some pictures. Could the check valve be in the intake? Nahh couldn't be right..? This braking problem always appears after the car has sat there for a while. This time it was just 2 hours and happens as soon as you start the engine and roll and then try to brake. Never has it done that it while driving or normal operations thank God! From what I see the hose connects from the brake booster to the intake. Nothing else in either end of the hoses.

[WyrTwister]

In the first photo , is the device I have circled in red , part of the brake booster vacuum system ( with the zip tie on it ) ? I do not think so ?

In the second photo , the area circled in red appears to be where the vacuum hose attaches to the booster . Where does the other end of the hose attach ? Should be at the engine , at a vacuum source . Intake manifold ?

Also , as a shot in the dark , have you thought about replacing the rubber hose ? Should be fairly inexpensive ?

More Information for ACDELCO 1761332

God bless
Wyr

[jamesd]

In the first photo , is the device I have circled in red , part of the brake booster vacuum system ( with the zip tie on it ) ? I do not think so ?

In the second photo , the area circled in red appears to be where the vacuum hose attaches to the booster . Where does the other end of the hose attach ? Should be at the engine , at a vacuum source . Intake manifold ?

Also , as a shot in the dark , have you thought about replacing the rubber hose ? Should be fairly inexpensive ?

More Information for ACDELCO 1761332

God bless
Wyr

In first picture it's not tied in directly to the brake booster. On the second picture the hose it tied it directly to the intake manifold. I have not replaced the hose but.. why not right? So I will do that. As far as checking it I had the engine running and I got a spray bottle with water in it and mist all the hoses and listening for a vacuum sound. I could not hear non at the brake booster hose or at the intake side. I sprayed the rest of the engine and I did find a vacuum leak at the PCV valve hose. Fixed it, resprayed and couldn't find any more vacuum leaks.