krankykoot

After 85k I figured I needed new rotors and pads on my 2010 Infinity G37 Sport Sedan (I didn't but that's another story) so I installed full Stoptech Select Sport Axle Pack both front and rear. All went well with installation, bled and then seated using procedure outlined on their web site (10 stops from 50 to 10) but the pedal was soft / spongy upon initial apply of brakes. Had a solid feel after a pump or two. Bled them again to make sure but they were still soft. It has gotten better after driving a bit but still need to pump at least once before I get a solid feel.

Questions:
Will it continue to improve? Have travelled less than 100 miles.

OEM pads in front had backing plates that I did not use on the Stoptech pads. Stoptech includes all of the other hardware in their kit so I assumed that they were not needed. Should I have used them? I have them so I can still put them on.

Thanks for any help you can provide.

P.S. The original rotors (and pads?) look to be in good shape if anyone is interested. Either I am a great driver or Infiniti makes their cars to last. The new Stoptechs look great so I am happy with that but I probably could have gotten away with new pads in the rear and been done. I had changed the front pads (Akebono) around 50k but I figured that I would be needing rotors.

Baadnewsburr

iTrader: (3)

Welcome to the site!

Did you bleed the ABS system too?...IIRC, you have to disconnect it from behind the master cylinder or have the car running when you do the bleeding

krankykoot

Thanks. Didn't know about the ABS but I did have the car running when bleeding the fronts the second time. And yes I did bleed both cylinders in the front. I am now thinking that was the reason why the one person vacuum bleeder using my air compressor didn't work. Kept showing air bubbles till I went back to two person manual bleed.

Did another search of the site and found brake bleeding posts and shop manual. Looked for the ABS connection and wasn't sure if it is located next to the master cylinder. Shop manual did not show good view.

JSolo

iTrader: (14)

@OP Did you have a firm pedal before you started all this?

Did you clean off the gunk on the pistons in the calipers before pushing them back in? No pulsation or judder in the pedal?

krankykoot

Did attempt to clean the calipers with brake cleaner. Pads were in pretty good shape so the pistons were not out far. No pulsation of judder. Real solid pedal with a quick pump. Would adding the shims back make a difference?

JSolo

iTrader: (14)

I haven't done a brake job on this car yet, but would do brakes often on the bike (similar 4 piston caliper design but on a small scale). Before pushing the calipers in I would get as much gunk off around the pistons usually using either a rap and/or qtips dipped in brake fluid.

You didn't answer the first question. Did you have a solid pedal before or it required a pump or two before it was hard?

My guess is you have air in the line too. I've bled brakes on this car at least 3 or 4 times. Always in the off position and never touched the abs module. I use a motive power bleeder so no helper necessary. I will say this, brakes on this car never grabbed immediately, usually require some amount of depressing before they could be felt. Our honda grabs right away, even with a minute amount of pedal pressure. From there the difference is the honda requires more pressure for similar stopping power (even though it's a lighter car with standard single or dual piston brakes).

Sport brakes have 2 bleeders on each caliper (at least in the front, can't recall the rear). You did do all of them right?

krankykoot

Sorry didn't see the first question. I did not have a firm pedal before starting. Reason for the change was pedal had been going down further and since I have 85k on the clock I figured it was time. I am old and remember when you only got 20k out a set of pads so... I used a one person bleeder from Harbor Freight which didn't work - either user incompetence or you get what you pay for.

JSolo

iTrader: (14)

DIY: How to Bleed Your Brake Fluid Using Motive Power Bleeder 0117 (AK370Z) - Nissan 370Z Forum

Baadnewsburr

iTrader: (3)

This is also a great video on bleeding the brakes, he shows where the ABS module is and how to disable it about 1:40 in :

krankykoot

Thanks again Hashim. Great video. Interesting that he found a clogged bleeder fitting. Also had that issue. And never would have found that ABS disconnect back there. I'm going to give the bleed another shot.

His video shows the bleeding system applying pressure at the master cylinder which makes much more sense that the one I attempted to use. The one I used attempts to create a vacuum at the bleeder valve by using an air compressor that caused more problems that it was worth. There are a ton of alternatives including DIY that I am going to try. I just jumped into this thing without doing the proper research in advance. No one ever does that right!

Other videos from him confirmed that my K&N intake added power although I installed the full intake.

Baadnewsburr

iTrader: (3)

yup. his videos are fantastic.

FWIW, I have had the clogged bleeder issue on my Akebonos too...ended up just slapping on new ones last time I did a bleed... maybe its a common issue,

Either way these cars definitely aren't as easy to bleed as my wife's Honda or my mothers' Toyota and I always use the Motive bleeder Jsolo referred to above on all these cars.


Good luck!

krankykoot

Been awhile since I posted last but I am just digging myself a hole here with these brakes. When I first installed and bled the brakes (without disconnecting the ABS) I had a bit of a soft pedal that went away with a pump. So thinking that I didn't bleed them fully (after all the great advice here) I went back for a second try after disconnecting the ABS. First attempt was the old fashion, 2 person way which is the recommendation of the OEM manual. During the process the pedal went to the floor and we couldn't get much pressure on the system. I was paying attention to the fill level but it may have gotten low. When you add fluid it fills to the top of the neck but then takes awhile to percolate down so I may not have gotten it full every time. I then invested in the Motiv power bleeder which seemed to work and is a whole lot easier. I went through 2 quarts of fluid making sure that I had all the air out but now I have a very soft pedal that won't hold after pumping

The question is did I damage the master cylinder when the pedal went to the floor during the bleed process? There are no leaks either at the MC or at the calipers. The pedal is solid with the motor off. If I hold the pedal down and start the car the pedal will go down a little and stay there. If I pump it up and then turn off the motor the pedal goes down a bit again. While driving the initial press has the pedal go down about half. A pump brings it up but it then mushes back down till I pump it up again. From what I have read on the web it looks like my MC is bad but I am hoping someone has an alternative that will save me having to try to change it in that tiny space.