[A_Slovakian]

Hey everyone, I know there's a million "my brake pedal is squishy" posts out there but none really fit my exact scenario. I changed my front brake pads today (first time I've ever changed brake pads before) and now I'm experiencing a seriously squishy brake pedal. Pumping the brakes gives me a firm pedal (engine on and off) but it fades almost instantly, and I just can't get the car to stop anywhere nearly as quickly as it did before the change. When I did the first side, everything went swimmingly, I didn't even need to compress the piston to get the caliper back on with the new pads, but the other side I did. As this was my first time, I didn't know to open the bleed valve or the master cylinder cap when compressing the piston. Have I done permanent damage? Is this temporary? How can I get that pedal feel/stopping power back?

 

[NCST1]

I can think of 2 possibilities. First, when changing pads, there will be a small gap between the surface of the pad and the surface of the rotor until the pads seat in. This will be worse if the rotors were not resurfaced or replaced. So, every time you step on the brake, you have to bridge this gap before contact is made, and you will feel this as a soft pedal. The fact that pedal feel is better on the second application supports this. You might just need to bed in the pads. Second, did you change to a different compound of brake pad? Some pads will give better pedal feel than others.

 

[kshatt06]

Hey everyone, I know there's a million "my brake pedal is squishy" posts out there but none really fit my exact scenario. I changed my front brake pads today (first time I've ever changed brake pads before) and now I'm experiencing a seriously squishy brake pedal. Pumping the brakes gives me a firm pedal (engine on and off) but it fades almost instantly, and I just can't get the car to stop anywhere nearly as quickly as it did before the change. When I did the first side, everything went swimmingly, I didn't even need to compress the piston to get the caliper back on with the new pads, but the other side I did. As this was my first time, I didn't know to open the bleed valve or the master cylinder cap when compressing the piston. Have I done permanent damage? Is this temporary? How can I get that pedal feel/stopping power back?

That and just bleed the system and top off fluids it doesn't take long to do.

 

[A_Slovakian]

Hey guys thanks for the replies. I'll give it a few days to see if it is just a bedding thing, if it doesn't improve after a few runs I'll have to try bleeding them. Thanks again!

 

[Lou64]

You could also have a bleed screw not closed all the way. I would check that first as it would be the easiest. Then bleed, then drive again. If you have a lot of bubbles the second time, something more is afoot.

 

[Xrdude]

So it sounds like you didn't open any bleed screws or anything, so you shouldn't have air in the system. As mentioned already check to make sure you don't have a big lip on the edge of your rotor that your new pads are making contact with first. Another thing to check is to make sure you haven't broken or bent a pad, you will need to take them back to check this.

 

[The STig]

Sounds like a mechanical issue for sure, not hydraulic. Take the wheel off, and have someone else press the brake pedal while you watch for lost motion at the pads. Repeat for the other side if you don't see an issue on the first side.
BTW, I've changed too many brake pads but still managed to cause this exact same issue on a car I used to have. One of the pads was not installed just so and it caused lost motion before the it got into position.

 

[Shadow5501]

If you pump up the brake pedal until it is firm and hold pressure on it, does it then sink towards the floor? If yes, then you have a hydraulic problem - either a brake fluid leak or the master cylinder has failed. A leak should be obvious, check around the lines and calipers. Sometimes when pushing the brake pedal to the floor to extend the caliper pistons after compressing them, the seal in the master cylinder can be damaged and cause a soft/sinking pedal. But this mostly happens on older cars where there can be rust or debris in the section of the master cylinder bore that is not normally swept by the piston. I would not expect it on anything as new as the ST, but anything is possible.

If the pedal stays firm after being pumped up and held, then likely something is pushing the caliper pistons back in when the pedal is released.

 

[sleestak]

did you not put the clips on correctly and loose one? As said, you should go back over everything. Don't wait for it to fix itself.

Sent from my SM-G930P using Tapatalk

 

[DanM]

I can think of 2 possibilities. First, when changing pads, there will be a small gap between the surface of the pad and the surface of the rotor until the pads seat in. This will be worse if the rotors were not resurfaced or replaced. So, every time you step on the brake, you have to bridge this gap before contact is made, and you will feel this as a soft pedal. The fact that pedal feel is better on the second application supports this. You might just need to bed in the pads. Second, did you change to a different compound of brake pad? Some pads will give better pedal feel than others.

... This.