Heater problem? Vacuum?

[84cutspreme]

Okay, what is actually needed for heater to work properly? What I am asking is in reference to vacuum lines. Do you need a vacuum canister? Any check valves?

Right now in my 84 cutlass I have a 350 sbc. I think the problem is vacuum related so I'm just trying to see how you guys have yours set up? Right now I only have to vacuum lines coming from heat and a/c controls. One goes to manifold vacuum and the other goes to my heater control valve. I am wondering if I need to re-install the small vacuum canister w/ line in and out, or a check valve in line, or both?

Any help appreciated

 

[joeairforce]

I would say at the least you need the check valve. As long as your HVAC system doesn't have any leaks you should be fine without the canister..... Without the check valve though the system would lose vacuum and default to defrost when you accelerate...... Then go back where you had it as vacuum comes back.....

Mine is set up with the check valve being the first thing then it goes to a T where the HVAC supply line is hooked up, and the other side of the T goes to a canister (I think..... I can check tomorrow if I remember)

 

[84cutspreme]

Thank you for input, I am getting the 2way check valve. I checked out my friends stock 85 w/ 307 and it had the 2way check, one going to HVAC other going to a tee and from there to canister and cruise control. Hopefully my problem will be solved. I also checked the vacuum going to HVAC and it only works on cold, then vacuum drops off. The doors are operating fine now with it set to cold so the check valve should do the trick and equalize the vacuum. Thanks again