Every now and then after I coast with no throttle, when I hit the breaks hard, or soft the truck stalls immediately. I put it in neutral or park after and starts right up. Trans has high miles sometimes I lose the rpm Guage but I think that is a separate issue. Anyone have any ideas?

 

If you're park and step on the brakes does the idle change? Suspect brake booster if so.

 

Diesel. Likely hydraboost.

 

My Bad.