Moan/squeel after shutting off engine

[Cupped_up]

I’d say about 75% of the time when I shut the engine off and sit in the truck for a minute, I’ll hear what I can only describe as a whale noise mixed with one of those squeeking chickens slowly coming from somewhere behind the dash. I haven’t been able to get out and check or record it due to it lasting only 10 seconds or less. Anyone know what this could be?

(I’ve checked under the hood for whales and chicken squeekers and haven’t found any).

 

[Scap]

Probably just a vacuum diaphragm releasing.

 

[jkm312]

Might be the parking brake setting itself.

 

[6of36]

I agree with the first two responses, possibly vacuum for HVAC, or auto parking brake. You can have someone help you, listening in different areas, to locate, but may be normal.

 

[Cupped_up]

I can hear the parking brake set so it’s not that.it does sound like some type of air squeel… if this is the case, is it something that needs to be addressed or is it normal?