Hey, who wants to help trouble shoot a car? (Brakes)

[Scanker19]

2016 Kia Forte

The what it?s doing:
at any speed when I brake is get a long groan. Not a grind or a squeal, but a groan. Almost metallic. At the end of the groan, or as I like to call it, when I stop, I can hear what sounds like fluid flowing or squishing.
It should be noted this noise is cyclic. 60% of the time it?s every time. It will go away for half a trip somewhere and then return at some point within the same day.

It needed brakes on the front so I replaced the rotors and pads. Inner pad on passenger side is asymmetrically worn. It was worn almost to the metal. While the outer pad had some life.

What I?ve done:
changed pads and rotors.
changed calipers
hub bearings seem okay.

what it?s not doing:
not pulling when braking.
was vibrating but the rotor change fixed that.
break pedal feels normal
stops As it always has.

[Wulf202]

Year make model?

Car, with disks up front is all I can tell so far. So that's 1970s or newer.

[Scanker19]

Year make model?

Car, with disks up front is all I can tell so far. So that's 1970s or newer.

I guess that would be super helpful.

[00tec]

Do you feel anything in the pedal when it happens?

[Scanker19]

No pedal feels pretty normal. It was vibrating, but after the pad and rotor fix that stopped.

[Wulf202]

Did you fully bleed the brakes after replacing the calipers?

[mb504]

Air in the brake lines? Maybe bleed them out?

[Scanker19]

I think I bled them out all the way. It was making that noise before I changed the calipers.

Funny enough o got a letter from Kia today saying that they issued a voluntary maintenance for corroded brake lines.

[zteknik]

Sounds like it can be an ABS issue, does the pedal hop and make noise when braking?- false abs activation- Is the pedal travel normal? Does it get squishy or does it feel hard when pressing? Check for vacuum leaks. That would cause the pedal to get hard, brake booster may have a leak. Is there signs of fluid loss? Loss of fluid can point to a leaky master cylinder. Separate master cylinder away from booster to see if fluid leaking into booster. Another thought can be the abs motor. Sometimes you have to do an abs bleed service procedure with a scan tool.
That's about the best I can do without actually putting hands or eyes on the vehicle.

[JohnnyEgo]

The fluid surging sound combined with no apparent issues with brake fade or squishy pedal feel makes me think it isn't brakes that are your issue. Brake fluid isn't very high volume compared to other fluids, and there isn't much space for it to even make surging sounds outside of the master cylinder and reservoir. If you had fluid low enough to make a surging sound in the master cylinder, I suspect you'd experience brake issues. Having said that, squishy feel is a sign of brake issues, usually air in the system.

Assuming it isn't the brakes, I'd consider what else might have fluid in it and be stressed under braking. Condensate drain tube blockage or air in the radiator or heater core circuit will cause a sloshy sound that you'd likely notice when braking.