Cruise control check valve question

[Pdwight]

I have a 94 Limited, Im trying ot trouble shoot the cruise control. There is a check valve between the vaccume servo that actually puts tension on the throttle linkage using a cable. How much vaccume difference should there be on the vaccume servo side ?? should it be equal or greatly reduced ??. I puled the vaccume hose off onthe engine side and it really gulped air and almost died so I put it back on quickly (didnt want it running lean) then I pulled the hose off the other side of the check valve and the vaccume was probbly 1/10 and the engine didnt even react to it being removed....is there a test procedure ??
Thanks
Dwight P