Cruise Control Not Holding Speed

Recently the cruise control in my '94 Sentra LE started acting up. It worked great before. When I set the speed (lets say at 60), and take my foot off the pedal, the car starts to slow down...maybe from 60 to 55 in a minute or so...and keeps going down.

I haven't taken a look at it yet but it seems like a leak in the vacuum system. Diaphram? Anyone else have a problem like this...if so what was it?

I'm going on a long trip in a couple weeks so I'd like to get this fixed.

Any info would be great...I plan to get out to take a look soon.

Check the vacuum hose going in to the servo, mine was doing the same thing. A pinhole in a vacuum line will give you a headache