I have a 1998 Dakota, 5.2L 4x4. I have only owned it a short time and have not really driven it that much. Probably less than 500 miles in the last 4 months. It seems to drive good but twice yesterday I noticed that when I took my foot off the gas pedal when coming to a stopping situation, I could hear a "moaning" noise (is the best way to describe it) and the brake pedal would feel stuck in the highest position and I could not depress the brake pedal, but after a second or two, the moaning would stop and I could brake normally. To my limited knowledge it seems to have something to do with the brake booster or the ABS system. Has anyone encountered anything similar?

 

I am not there, so I can't say for sure - but my first check would be the booster, yes.

It's not uncommon for one to "moan" or "whooosh" as the diaphram dies with age (which it does, depends on which side it's leaking at).

Also, be prepared if you're doing it yourself - if there's ANY brake fluid in there, the master cylinder is leaking slightly, and needs to be replaced ALSO.

RwP

 

yep, sounds like you're hearing the booster come back under peak vacuum and the diaphram moving. Refer to what ralph said.