Vacuum?

[logan13883]

I have a 96 v6 camaro and my air only blew out of the defrost vents , well i had bought a new vacuum check valve and that didnt fix it so i did some looking around on the tubes and saw that there was no vacuum coming from the long tube running to the front of the car, so i got under my car and checked it out , and the box/tube that it was hooked up to was making no vacuum and all of my lines are good , i was just wondering if anyone knew about this problem and what could be the cause , but i did find a vacuum extra vacuum from the top of the engine so i ran a tube from that to the check valve and now the air blows out of all the vents and such, thats untill i give it alot of gas then it goes back to defrost , anyone know if that can hurt anything also? well just wondering what anyone thinks about this ...

[Chevy16]

Re: Vacuum?

i have that same problem with my 96!!!! i have no clue whats wrong either

[logan13883]

Re: Vacuum?

Well i found a nice picture to help explain what iam talking about , its the "vacuum tank" in the picture , its not making an vacuum for me , anyone have any idea why? or how hard/much it would be to change it?

http://shbox.com/1/vacuum_tank.jpg

[Rob Bell]

Re: Vacuum?

I would suggest hooking up a vacuum pump to that tank and checking to see if it can hold a vacuum. If it does, then work your way back to the check valve and/or engine to determine where the leak is. The reason your HVAC goes back to defrost when you hit the gas is because there is no vacuum when the engine revs. That's why they put that tank on there, so you have a vacuum resovoir. Defrost is the "default" setting for safety so in case you lose vacuum you can still see out the windows. Believe me, a vacuum pump w/ a built in gauge is a very handy thing to have around.

[Joey41]

Re: Vacuum?

I have had a smilar problem with my 97 camaro. When I get on the highway the air through the vents shifts to the floor... I do not think that it goes up top, but I will have to check when I leave work.

I know my check valve is good - just replaced it.

I also just replaced the vacuum tube that goes from the check valve to the vacuum tank - my original had been cut. Good luck finding one of these - I got one of the last 2 in Cheverolets find a part system...

Just changed the gasket on my intake manifold so I had everything taken apart up on top of the engine. Didn't notice anything out of the ordinary with the vacuum hoses, I did replace one with a new one from the dealer and 1 connector.