mediaman67

Hi All

I have a 1993 lumina Sedan, 3.1 - pretty common car...

I have the issue where when the ac is on, and you put the engine on load,, like climbing a hill, there is very little coming out of the vents... and when coasting down a hill, it gets a bit better about blowing stronger.

actually, in general, it doesn't blow as strong as I remember even at idle on MAX AC - talking air movement here...

I'm sure it's vacuum related, but where do I look to see if the canister is disconnected, or rotten hose to it, and from what?, etc... been driving us crazy...

if you know this car, please clue me in as to where it would be located - that would be sooo helpful :-)

Thanks

rkuelbs

When the A/C blows less, have you noticed the air coming out from the defrost or floor vents? If so, I would suspect a vacuum problem. The vacuum reservoir is located under the Left side headlamp, it is a plastic ball about 5-6" around.

I would recommend following the vacuum lines to the reservoir. Between the reservoir and engine you will find a check valve, test the check valve to be sure you can only blow through it one way. If the check valve works, you likely have a small vacuum leak in the reservoir, or in the hose between the reservoir and engine or reservoir and a/c unit.

mediaman67

Thanks, I'll check all that out - yeah, it tends to get "diverted" to the floor when engine is under load.

how would I test the check valve? just blow air through it lightly both ways? and if it works both ways, it's a bad valve...

I guess I can't use a soup can if I have a reservior leak lol - I just assume that these are dealer only parts?

Thanks