fejjj

Normally when my AC is running, when I get on the boost 😊 my air flow through the vents gets restricted.

Today I had the opposite situation.

When I got on the boost the air flow increased.

What say you all mighty RL brain trust?

Scott H

Verify the condition of your check valve, if that's fine, use a Mity-Vac or similar to see if you can pull and hold vacuum on the HVAC system.

Diagrams of the vacuum routing can be found in this thread (968 forum but the layout is the same in the 951)
https://rennlist.com/forums/924-931-...s-routing.html

fejjj

Thanks Scott,

If it is working properly, I would see reduced airflow under boost, correct?

Scott H

If it's working correctly then on or off boost should have no effect. The HVAC has a reservoir up near the battery that keeps a supply of vacuum. When you're on boost the check valve is shut and the HVAC gets vacuum from the reservoir.

fejjj

How do I verify that the check valve is working correctly?

Willard Bridgham 3

Blow through it. If you can only blow through it in one direction, it's working.

fejjj

Where is it located?

Tedro951

Did you open the link Scott posted?

fejjj

Yes

sketchers356

Its near the rear of the engine. If memory serves me right it is blue with some white.

gruhsy

Fejjj. There are some pics of the check valve on page 6 of my build thread.

"finally finished cleaning the engine bay"

There are some good pics of the heater box and config for things in the engine area.

I'm using my mac which sucks for cutting and pasting pics so you will have to look up my thread.

fejjj

Thanks guys. I found it but it looks like a pain in the a$$ to get to like most every other part in our engine bays.