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

[xintersecty]

Thanks and here is an other consideration we can use science! Put a vacuum gauge on your line to the brake boost, let it sit, start the engine, and then engage the brake. That should indicate a failure on the vacuum system. Once it warms up the leak could have closed up due to expansion.

[jamesd]

Thanks and here is an other consideration we can use science! Put a vacuum gauge on your line to the brake boost, let it sit, start the engine, and then engage the brake. That should indicate a failure on the vacuum system. Once it warms up the leak could have closed up due to expansion.

I will definitely try that. I also have a vacuum pump as well so I will give that a try as well. I checked with the GM techs who are checking my car and they said they cannot duplicate the problem. Basically they said they are puzzled by it. They day is still young tho..

[jamesd]

Oh on the part you asked about that has a zip-tie on.. I found out it's called INTAKE MANIFOLD VACUUM ACTUATOR for those of us like me was not sure what that was called. Part# 96859269. I learned something new... By the way I didn't put those zip-ties there. Previous owner did. lol

[WyrTwister]

INTAKE MANIFOLD VACUUM ACTUATOR

Not sure what that is . I thought it might be an EGR valve .

The vacuum hose to the booster does not connect to it ?

You still can test the system by hooking up a section of hose to the booster and applying vacuum to it .

God bless
Wyr

[jamesd]

I will try that. So the end result was they couldn't duplicate the problem and as much as I tried I couldn't either when I was driving it. The tech even drove the car with me in to replicate the problem. None.. We braked, braked and braked some more even going in reverse and it would not do it. He did find a whole in my coolant tank tho, pin sized and was leaking coolant. He patched it up for me enough so I can order a new one. No charge... He checked for vaccum leaks and found none that he could see. He said the master cylinder is top notch and working great and no leaks. The search continues.

[WyrTwister]

This is our 2015 Sonic 1.8l . Obviously quite a bit different .

One photo is where the vacuum hose hooks to / taps into the intake manifold . The other where the hose joins another hose at the booster . And may have a check valve at that point . Or not ?

Instead of trying to find a vacuum leak with water , spray the suspecter part with something combustable . Even propane from an un lit propane torch . If you hit a vacuum leak engine speed should increase with the added fule being suched in .

God bless
Wyr

[jamesd]

Thank you WyrTwister for taking the time to take the pictures. Wow talk about hardware changes! I see what you were talking about. Mine has no check valve but of course if any ones wants to correct please do.

[jamesd]

Here are some better pictures of my car.

[WyrTwister]

Is the 3rd photo where the booster vacuum hose connects with the intake manifold ?

Is it the larger hose ?

I would detach it and test it . And probably replace it . May be fun getting to it . Looks like you need long pliers to squeeze the spring clamp .

God bless
Wyr

[jamesd]

Is the 3rd photo where the booster vacuum hose connects with the intake manifold ?

Is it the larger hose ?

I would detach it and test it . And probably replace it . May be fun getting to it . Looks like you need long pliers to squeeze the spring clamp .

God bless
Wyr

Yes sir! You are correct it's the larger hose and it connects right into the intake manifold. As far as getting in there to unhook it, yeah it's going to be fun. But it gives me an excuses to go to Harbor Freight to pick up some long pliers haha.