Brake fluid disappearing... no visible leaks?

Seeking Advice Forum
1

My 2011 Kia Forte Koup keeps losing brake fluid. I have to top it off every couple of days. There’s a small puddle under the engine, but no visible leaks near the wheels. Anyone know what could be causing this?

2

Did you check the brake lines at the ABS module? Sometimes they loosen and leak under pressure.

3

Ash said:
Did you check the brake lines at the ABS module? Sometimes they loosen and leak under pressure.

Haven’t checked yet, but that’s a good idea. The puddle is under the engine, around the driver’s side, near the fluid reservoir. Could that be related?

4

@Myles
Yeah, it could be. The ABS module is under the hood, driver’s side. You might have to remove the air box to see it clearly.

5

Ash said:
@Myles
Yeah, it could be. The ABS module is under the hood, driver’s side. You might have to remove the air box to see it clearly.

Got it, I’ll check that out. Thanks for the heads-up!

6

Is your fluid reservoir loose? Mine was wobbly, and I had the same issue with losing fluid. Tightening it up helped a lot.

7

WhisperingWillow said:
Is your fluid reservoir loose? Mine was wobbly, and I had the same issue with losing fluid. Tightening it up helped a lot.

Yeah, it actually moves side to side a bit, like half an inch. Should it be tighter than that?

8

@Myles
It should be mostly solid. A little movement is normal because of the rubber bushings, but what you’re describing sounds excessive.

9

WhisperingWillow said:
@Myles
It should be mostly solid. A little movement is normal because of the rubber bushings, but what you’re describing sounds excessive.

Good to know. I’ll check the mounting screws and o-rings.

10

Did you have the master cylinder replaced recently? Sometimes that’s the culprit for leaks.

11

Rowen said:
Did you have the master cylinder replaced recently? Sometimes that’s the culprit for leaks.

I replaced the master cylinder about 4 months ago, so I think that’s probably fine. But I’ll take another look just in case.

12

Could the power brake booster be causing the fluid to leak? I’ve heard of that happening before.

13

MegWhitgal said:
Could the power brake booster be causing the fluid to leak? I’ve heard of that happening before.

I was wondering about that too, but I’m not sure. Do you know if a faulty booster could actually leak fluid?

14

@Myles
It’s rare, but yeah, it can happen. You might want to check it out just to be safe.

15

DriftKing said:
Check all the brake lines and connections. Even if you don’t see a leak, it could be a small one causing the puddle.

Will do. I’ll double-check everything, especially around the ABS module. Thanks for the tip!