74-78 ATC II to Manual A/C Inspection (and conversion??)

[73 T&C]

I indeed did use a needle. Pins are too soft. But first I put the check valve on a hand held vacuum pump. To help gauge the size I had made. I start with the smallest needle in my wife’s sewing kit going up in size and when it takes about 20 sec to lose all vacuum in a 12” length of hose I stop. I push the needle down inside through the opposite side nipple.

 

[SuicideDoorLincoln]

Stan just look up "four wheel drive vacuum actuator "

Never heard of these electric units. Got any key words I can use to start my Googling?

 

[1978 NYB]

Stan, isn't your current NYB manual A/C???

 

[commando1]

Stan, isn't your current NYB manual A/C???

Nope. ATC. And I hope I don't jinx myself by saying it works perfectly.

 

[1978 NYB]

Stan.....Is that spare A/C box that you have is manual or ATC?

 

[commando1]

The unit on the shelf is a complete manual setup.
I also have NOS replacements for all the ATC doodads and thingamabobs that can go bad.
And... a factory ATC II test box plus several Technician books.

 

[1978 NYB]

Wow! All this time for some reason I thought it was the other way around....

I hope the ATC keeps working for you. You are one of the very few that has a working ATC system.

 

[commando1]

I hope the ATC keeps working for you. You are one of the very few that has a working ATC system.

Now you've done it.

 

[jct]

Jinx!!!

 

[73 T&C]

Have you checked the vacuum canister? If ok then check the direction damper actuator on the top of the box for a leak.

Both would give you the symptom you mention of shifting direction due to vacuum loss.