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

Hi Guys! I'll try to take as many pictures as I can. More storms last night so not much was done last night on my poor Aveo. My intake is all plastic. I received all 3 replacement hoses. Two small ones and the brake booster hose. My car never cranked out any codes until this week which was P2279 followed by P0507. This morning the car did it again, no brakes. My daughter turned off the a/c and brakes started working again. Another thought would be intake gaskets but by just looking at how this car is put together it's going to be a pain to replace. I'll report back my findings. Before even going down that road I will do another propane test on the hoses and then do a smoke test with my homemade smoke machine.

https://www.google.com/search?q=+P22...utf-8&oe=utf-8

https://www.google.com/search?q=+P05...utf-8&oe=utf-8

Sounds like you have a problem around the intake and or throttle body ? IAC is attached to the TB ?

I need to think about this ?

Still thinking there must be a check valve between the intake manifold and the booster ? Unless it is built in the booster ( do not think so ) or the fitting on the intake where the booster hose attaches .

And I do not know how this ties in with the two engine codes ?

But , you did say you had the TB replaced ?

God bless
Wyr

Yeah the IAC is brand new, it came with the new TB along with a new hose going to the air filter box. I have to recheck the hose connections. I had this car for a month and one week and these codes just came up. The TB was done on 4/25/2016. But based on the P2279 it seems like a leak some where in the metered side of the intake manifold. I also tried looking for a check valve for my car and nothing comes up. Not even on the GM catalog at the dealership. Oddly enough I did find an image on the internet for a different model year of a Aveo and it shows a inline check valve between the booster and intake manifold. Basically it look like two booster hoses with a check valve in between them. Maybe a redesign after these brake problems surfaced??? I wanted to post the image but I could not find the site/image. Darn!

It may not have been standard on your car , but that inline check valve might solve some problems . But with the 2 codes , it sounds like you have other problems , too , now . :-(

Do you remember what model yera had the inline check valve ?

God bless
Wyr

Amazon.com: ACDelco 176-1332 GM Original Equipment Power Brake Booster Vacuum Hose with Clips and Check Valve: Automotive

This says it has a check valve and I think it is the same part # in your photos !

I think you can verify that by trying to blow through the hose . If it passes air , try blowing in the other end of the hose ?

God bless
Wyr

PS Check the 2nd consumer review .

What????? Ok let make a trip to my car to check my hose. I haven't even opened the package it came in yet.

Quote:

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Originally Posted by WyrTwister

Amazon.com: ACDelco 176-1332 GM Original Equipment Power Brake Booster Vacuum Hose with Clips and Check Valve: Automotive

This says it has a check valve and I think it is the same part # in your photos !

I think you can verify that by trying to blow through the hose . If it passes air , try blowing in the other end of the hose ?

God bless
Wyr

PS Check the 2nd consumer review .

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I'll be a monkey's uncle! The darn hose does indeed has a check valve built into it. It looks just like a regular hose. No indications that it has anything else in the hose unless you blow in it. Wow.. You are a genius! I'm questioning my skill set now considering this is one thing I had not checked. I was expecting some other external check valve at the booster or intake. Dang... I am hoping this will resolve the issue with P2279. I will install the hose tonight and report back. I will do a vacuum leak test to cover all bases just to be sure.

Quote:

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Originally Posted by jamesd

I'll be a monkey's uncle! The darn hose does indeed has a check valve built into it. It looks just like a regular hose. No indications that it has anything else in the hose unless you blow in it. Wow.. You are a genius! I'm questioning my skill set now considering this is one thing I had not checked. I was expecting some other external check valve at the booster or intake. Dang... I am hoping this will resolve the issue with P2279. I will install the hose tonight and report back. I will do a vacuum leak test to cover all bases just to be sure.

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I too expected an external check valve . Did you try blowing through it ?

If it does indeed have an internal check valve , inside the hose , if you install the hose backwards , you will probably not have any power assist . :-)

Of course , sadly , it also means the booster & master cylinder you replaced were not defective . :-(

God bless
Wyr

Any news / luck on the engine codes ?

God bless
Wyr

Quote:

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Originally Posted by WyrTwister

Any news / luck on the engine codes ?

God bless
Wyr

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Hi everyone! Sorry for being MIA. Spent some quality time with the family but I did work on the car a bit. I did change the brake booster hose. I started up the car and.... no check engine light! Drove the car around the block and no light at all. I hooked up my scanner to the car again and it showed the same code P2279 and P0507 except, the CEL was not on any more. So I cleared the codes. The following day I took the car for a drive. Brakes work great.. so far.. Since this problem happens sporadically I haven't called this fixed just yet. I drove the car a bit and then the check engine light came on again! New code.. Now I have P0506 "Idle Control System RPM lower than expected." Before I reported back on here I wanted to double check on any vacuum leaks. I went over it with a blow torch with a hose attached to it several times and no change. I went over the hoses, trottle body, injectors and around the intake. Idling stayed the same. I'm scratching my head now on this one. The engine did stumble a bit when starting up but it leveled itself after a minute or two.