Recently purchased a 2013 Roush Stage 3 that did not have the Roush caliper upgrade, so it just has the GT Performance Pack brake setup. The car only has 20k miles, but the factory pads were dusting so bad and the brakes were noisy, I decided to put new pads on the car. I also noticed that the fluid level was low, so I filled up the reservoir prior to bleeding the brakes, and again when I finished the brake job.

My 2017 Mustang GT with the 4 piston front setup stopped on a dime with little foot effort, my 2015 Charger SRT with the 4 piston Brembos also stopped with no effort. The Roush doesn't want to stop when you apply the brakes! The pedal seems to go further to the floor than I would like and it just slows down at the normal braking pressure. I need to stand on them to stop.

The fluid that came out of the bleeder was brown, and all 6 bleed points were done. I did not completely replace all of the fluid, but I wonder if that could be part of the problem. The new pads are Powerstop Z26 performance pads. My only other thought is that the brake lines might have a problem, but at 20k miles, I wouldn't think that.

Any suggestions on steps to resolve this? I would think the Brembo calipers aren't the issue with the low miles, but I could be wrong.

 

 

Did you bed them in, when I put the Stop Techs on my F150 they would drop almost to the floor, felt spongy just as you are describing.
Took them to the deserted road with the break down lane and did the 50-10 10 times on them and then drove far enough to let them cool and they do stop my truck on a dime and offer a couple of cents change.

 

My son drives the car. I'll ask him if he bed them yet. I told him he needed to do it after the brake work, but I don't know if he did. If not, we'll do it today and respond back with an update.

 

Took it out and bed the brakes. I don't notice a difference. The pedal feel is still not what I expect. After driving my sons car around and just playing, I came back home to get the truck and run an errand. Hopped in the truck and almost went through the windshield at the first stop sign. The difference in feel is considerable. I wonder if I should take it in and get the brakes bled on a machine that can activate the ABS and remove all air from the system.

 

 

The hoses look ok and there's no fluid on the wheels.

 

If it is not leaking it almost has to be air in the lines. Since you said that the fluid was brown, i would do a complete fluid flush to remove the old fluid/air from the lines.

 

I wonder where the brake fluid went? Suggests you might have a leak, which might be letting air into the lines. Normally I would not expect to consume any brake fluid; the level will go down a bit as the pads wear but should some back up when you push the pistons back (unless you let it out of the bleeders).

I think I would start with a complete brake system bleed as the others have suggested; and a pressure bleeder (Motive sells them) is about the best way I know to do that. I tried they vacuum bleeder and it, well, sucked.

 

I should've clarified the low fluid level. It was at the minimum mark, I'm assuming, because the original pads were wearing. I filled the reservoir then bled the rear brakes before compressing the front pistons. If I compressed the front pistons first, I might not have been at the minimum level anymore.

 

Not sure why I didn't notice this before, but I drove the car today and determined that the car has manual brakes! I tried standing on the pedal to lock 'em up and they wouldn't lock up. No wonder it was easy to bed the brakes without activating the ABS.

I checked the 30A and the 40A ABS fuses and they were good. Has anybody heard of the brake booster going on these cars at 20k miles? The master cylinder would give me a soft pedal, so I'm leaning to booster. I do have vacuum at the booster, but...