vacuum modulator mystery

[Jones]

My 94 xlt vacuum modulator seemed to be malfunctioning so I took it out to check it. It was filled with tranny fluid, and seemed to be kind of hydro locked. The pin would hardly move at all, and would not return to position when it did move. I pumped the fluid out of it and cajoled it and Q-tipped it and and now it seems to work, as near as I can tell, but I wonder if it is shot or not? I've read that one test for the modulator is fluid in the vacuum lines, and the fact is that I didn't see any. Does that mean it is OK? I surely hope so, becuase otherwise I have no vehicle for tommorow. But if my modulator is good, how come it got stuck, and will it get stuck again? Thanks, as ever, for any and all help or suggestions.

Jones

 

[Glacier991]

The throttle valve in the bore should move freely, and it sounds like you got it to do that. A good sign. (side bar: Make damn sure you keep that pin in there.. it's misery if you forget it or lose it). For the $20-$25 it costs, replace the modulator. I believe everything will be fine for some time to come. You did a good job, pat yourself on the back.