Gurgles while breaking

My 2001 Corolla gurgles when I step on the brakes. It seems to be getting louder and louder. This has been going on for 4 months or so… I’m afraid somethings going to blow…
This happens when the car has been running for a while. I went to the garage, turned the car off and waited for 10 minutes to talk to the mechanic.
Of course when I turned it on there was no noise when I stepped on the brake pedal…the mechanic wants me to bring it in this week. I’m afraid he might not find anything but charge me an arm and a leg. Does anyone have any ideas on what this could be?

Thanks.
Nance

Are you saying that you can get this noise even while sitting still at idle and applying the brakes? Or is it always maybe associated with the change in momentum when you step on the brakes?

Yes, I\it’s when I sit idle…the mechanic thought maybe something was loose…are you a car person? What do you think?

You just might be low on coolant.

When you’re stepping the brakes the engine speed slows down. This causes the water pump to slow down. If the coolant is low and there’s air in the cooling system this air will rush to the heater core when the water pump slows down and cause a gurgling sound because the heater core is the highest point in the cooling system.

Tester

If I wasn’t a car person I wouldn’t be here - but there are better car people than I here as well. Like Tester. Have you checked your coolant? Brake systems don’t gurgle. But low coolant can.

Are you sure it’s a gurgle? Or would there be other words you might use to describe the noise?

If the noise is genuinely a “gurgle”, that would seem to point to a low coolant situation.

However, different people describe the same noises in different ways, and it is possible that the OP is hearing a noise from a leaking brake booster. I wouldn’t describe the noise of a leaking brake booster as a “gurgle”, but…maybe somebody else would.

With the shift lever in Park and the engine idling, will pressing the brake pedal cause the gurgling?

I’ll try the coolant, then report back to all…Thanks