Help me figure this one out. When traveling above 30mph and releasing the throttle it will idle @ 1000 rpm, then if I apply the brake pedal it drops to 500 rpm. If I release the brake pedal the engine goes back up to 1000 rpm.. Is this normal?

I dont know if its normal but mine does the same thing but it only drops to about 700-750. So i hope its normal.

Alex

Yep.

Mine does the same thing, it drops a couple hundred RPM. I checked the other 6.5's at work and they do the same thing. There was a post here before explaining this I think.

Your torque converter is working properly - pressing the brake pedal completely unlocks it. Someone correct me if I'm wrong, but I had the same question about 2 years ago and that was the answer.;)

Brake pedal releases the TCC - 1000rpm is not idle, it is engine braking rpm driven by driveshaft input thru the transmission

You can also hold throttle at cruising speed and tap brake and get the same opposite result when it's working. RPM should increase with unlock.

It's a protection feature for the 4L80E's hollow input shaft. It keeps from shearing the input off under engine braking.

I knew I asked the right people.... Thanks for the wisdom....