[Paulbates455]

I’m bummed. Purchased the gm 6 piston kit, matching red rear calipers, and the stainless steel lines from wild hammer. Took my 2016 ss m6 to a very highly recommended shop and had them installed. They told me the pedal was very squishy now because of new pads in the front and old ones in the rear. And it would firm up after a couple of weeks of use. The squishy pedal and the pedal travel is why I did this. Does this sound right? Or Do I take it in and have the dealer or another shop re bleed the brakes? This place is far from where I live and very busy. This car is my daily. And btw, the Goodrich or whatever front stainless lines wouldn’t fit the brake calipers. The parts, labor, and Uber set me back $3000+. The pedal is so freakin squishy now. Mad crazy pedal travel.
The car stops. But I have to push the pedal to the floor.

[PolynesianPowerhouse]

If theres no leaks, sounds like a poor bleeding proceesure. You still have air in the lines or calipers. A decent good bleed should fix the problem.

[travislambert]

If it's a problem with the pads not being bedded, you should feel the brakes get a little better each time you brake hard. If you have a place where you can safely go through the burnishing procedure, you can confirm or rule out this theory pretty quick.

What you describe sounds more like you have air trapped somewhere.

[parish8]

i have a similar issue that i partially figured out.

i did the smaller rotor and calipers in the rear to fit 15" rims. after the swap my pedal was soft and would push lower to the floor than before. why? **** if i know. i only changed the rear calipers and bled them like normal and never let the reservoir run low. there shouldn't be any air in the line. also the brakes seemed to drag at times.

i got ahold of a fancy scan tool that let me do an "automated bleed". it is a bit of a pain. you have to hook up a charger so your battery doesn't go dead and it pulses the abs and who knows what else while telling you what wheel to bleed. i went through something like a gallon of fluid. after all that the brakes no longer drag but the pedal does sink a little when i push it hard and not moving. on the street you never have to push it hard so you don't notice it.

long story short do the automated bleed and see if that helps. i am tempted to just rip all that abs crap out.

[Paulbates455]

I’m going to take it somewhere local and have them re bleed them. The stainless lines fit the back not the front. That’s why this is so confusing to me. New big brakes up front with low expansion lines. Stainless lines in the rear. Should be minimal pedal travel IMO. Thanks for the info.

[Alpha1BC]

What you described definitely sounds like air in the system. Having pads that aren't burnished or having old vs. new pads would still have a firm pedal feel and stop the vehicle from normal speeds without issue. If it was a leak allowing the pedal to go to the floor and not air, you'd get a low brake fluid light pretty quickly.

Something I've seen with switching to the Brembos, especially if it's a shop or person that hasn't worked with big fixed calipers like these before, is missing that there are 2 bleed screws per caliper. The inboard one isn't obvious just from looking at the outboard side of the caliper. I know of at least 2 people personally that have missed this when bleeding these brake kits, so I have the feeling it's not that uncommon for even shops to sometimes miss. I'd suggest starting there.

If that doesn't do it, next thing I'd try is bleeding the master cylinder and/or triggering the ABS module (either by a hard stop on a dirt road or with a service tool) then re-bleeding the whole system normally.

[travislambert]

Originally Posted by Alpha1BC

What you described definitely sounds like air in the system. Having pads that aren't burnished or having old vs. new pads would still have a firm pedal feel and stop the vehicle from normal speeds without issue. If it was a leak allowing the pedal to go to the floor and not air, you'd get a low brake fluid light pretty quickly.

Something I've seen with switching to the Brembos, especially if it's a shop or person that hasn't worked with big fixed calipers like these before, is missing that there are 2 bleed screws per caliper. The inboard one isn't obvious just from looking at the outboard side of the caliper. I know of at least 2 people personally that have missed this when bleeding these brake kits, so I have the feeling it's not that uncommon for even shops to sometimes miss. I'd suggest starting there.

If that doesn't do it, next thing I'd try is bleeding the master cylinder and/or triggering the ABS module (either by a hard stop on a dirt road or with a service tool) then re-bleeding the whole system normally.

I didn't think about the 2 bleeder valves per caliper until you mentioned it, but that does seem likely.

Also, the brake bleed order is a little different than what most mechanics are used to. It might be worth mentioning the correct sequence to them:

Right Rear Inner
Right Rear Outer
Left Front Inner
Left Front Outer
Left Rear Inner
Left Rear Outer
Right Front Inner
Right Front Outer

[bensf]

Originally Posted by travislambert

I didn't think about the 2 bleeder valves per caliper until you mentioned it, but that does seem likely.

Also, the brake bleed order is a little different than what most mechanics are used to. It might be worth mentioning the correct sequence to them:

Right Rear Inner
Right Rear Outer
Left Front Inner
Left Front Outer
Left Rear Inner
Left Rear Outer
Right Front Inner
Right Front Outer

Can you give me the rationale for the sequence you listed? I was taught to start with the caliper furthest from the master cylinder and do the one closest last.

[bensf]

Never mind. Saw another post indicating that's the sequence in the service manual. Thanks for the head up.

[travislambert]

Originally Posted by bensf

Never mind. Saw another post indicating that's the sequence in the service manual. Thanks for the head up.

Yeah I just pulled this from the service manual. I wish I knew the exact rationale.

I track my car, so I've bled my brakes more than a few times. Before I realized the new sequence, I had used the traditional sequence and didn't have any issues. I assume there's a difference, but I don't know what it is.

[Alpha1BC]

Originally Posted by bensf

Can you give me the rationale for the sequence you listed? I was taught to start with the caliper furthest from the master cylinder and do the one closest last.

Originally Posted by travislambert

Yeah I just pulled this from the service manual. I wish I knew the exact rationale.

I track my car, so I've bled my brakes more than a few times. Before I realized the new sequence, I had used the traditional sequence and didn't have any issues. I assume there's a difference, but I don't know what it is.

My guess is that it's due to how the system is split. I'd assume these cars have a diagonally-split brake circuit, meaning one port out of the master cylinder pressurizes the LF and RR corners, and the other port pressurizes the RF and LR corners. Maybe I'm missing something, but I'm thinking bleeding the corners of one circuit sequentially stops any potential bubbles in that circuit from working their way back up the system like they could if you took time to start bleeding the other circuit before finishing the first?

I also bled the traditional order the first time I bled my car due to not knowing any better and never had any issues, but I also never introduced any air into the system like OP did because I was just flushing the system through with DOT 4. Order probably makes more of a difference when you have a significant amount of air in the system.

[kropscamaro16]

when i had my ss brake lines and fluid installed they had a bitch of a time getting the pedal right they literally bled my system for like an hour or more lol sucks for them good thing they quoted me first

[TJay74]

Squishy pedal has nothing to do with the brake parts but more so has to do with the install and a improper bleed of the new brakes. If the shop let the master cylinder go dry then they will need to cycle the ABS module in order to get the system bleed properly along with the bleed pattern that was shown earlier in this post.

[parish8]

Originally Posted by TJay74

Squishy pedal has nothing to do with the brake parts but more so has to do with the install and a improper bleed of the new brakes. If the shop let the master cylinder go dry then they will need to cycle the ABS module in order to get the system bleed properly along with the bleed pattern that was shown earlier in this post.

i am 99.99% sure i did not let the master go dry and have a squishy pedal.

i stepped down to smaller brakes and might be experiencing caliper flex.