I'm chasing a soft brake pedal in my car that bleeding does not seem to cure (if it does it's temporary)

Seems then when i stop, i need to double pump the brake pedal to get a nice firm pedal. Normally it's soft, but still stops the car. Pumping the pedal gives it a nice confident feel.

Anyway, still under warranty so i had the dealer look at it. They came back with BS about the front calipers, rotors and pads being aftermarket and nothing they can do.

Now, the pads and rotors are OEM Nissan. I know because I bought them and installed them and purchased them from Infiniti, but the aftermarket calipers thing has me puzzled.

No i did not install a BBK, these are are the stock 05/06 2-piston brakes. I did paint them silver, so they look new. I bought the car at 26K miles and i haven't changed them.

Trying to call the dealer now to get them to elaborate, but how can i identify OEM calipers vs, cheap parts store replacement calipers. What markings would be on the calipers if they are original to the car when it had 0 miles vs some cheapo calipers? If they are parts store calipers, i want to know so i can troubleshoot why someone would replace both front calipers on a car with less than 26K miles and not do it under warranty.

I really hope the dealer isn't looking at my painted (silver) calipers and thinking they are not OEM.

 

It sounds like your dealership has some serious issues of the awareness kind. If they can't identify OEM pads and rotors that you installed yourself how could you trust them to properly repair or diagnose anything else.

As far as your calipers, I bet they looked at the paint and just assumed that they were aftermarket. I highly doubt the previous owner had calipers replaced at or before 26K miles. Sorry you are having to deal with these dimwits.

On another note, have you had any problem with the paint on the calipers? I painted mine a month ago with the G2 kit off eBay in silver and they turned out great. However, when I installed new pads last week and bedded them in, the paint on the rear calipers yellowed some from the heat. I'm surprised that the fronts weren't affected at all. Guess I need to buy some Duplicolor locally and try again.

Let us know how what you found out about your soft brakes.

 

Well after a couple calls, that's exactly what happened. Shiny silver calipers must be aftermarket. Apparently they were expected rusted out brakes or something. As for the rotors and pads, i have my receipt. I guess i can kinda see the tech's POV though as i did a kick *** job of painting them.


But in the long run they claim "there is nothing wrong with the brakes they are normal" and won't go any further.

There is a definite increase in brake pedal feel if you pump the pedal on stopping, so there is something wrong. But the car DOES stop fine if you get into the brakes hard...i just shouldn't have to pump to build pedal.

Gonna try a vacuum bleed this time, and replace all my bleeder screws wit new ones. I suspect air is getting in somewhere. Sucks that i need to chase this down now.


BTW, the paint is holding up fine. I have not done the rears yet (waiting til spring when i do a rear brake job) but the fronts are still nice and silver. I used the DUplicolor spray on caliper paint. Works well. The discoloring in the rear might be the steel calipers vs aluminum front calipers making a difference in heat retention. (i assume the rears are steel)

 

check ur brake fluid often to be sure ur not losing any,check ur bleeders and all brake lines,go to sears,they sell a bleeder brake pump specificly designed for bleeding brakes..ud be amazed how much air the lines can hold,ive done 2 sets of akenbono upgrades and the pump worked wonders,and its only 30.00

 

prob be best to put ur g on jackstands,as u will have to bleed in sequence 2-3 times

 

i have the same problem, if i tap the brakes once and release before getting to stop it bites very good on the second tap, but if i just press the pedal once coming to a stop it feels loose...i was thinking of upgrading to 2005 brake calipers, guess that won't fix the problem

 

These are from a 06 Z but I can't see that making any difference. You could also have air in your ABS system?
oem fronts:



Oem rears:

 

I experience this issue as well and have received the same story from the dealer. I'm thinking it might be a leak internally at an o-ring or something inside the master cylinder. Since the leak is on the inside, the tech will not see fluid leaking externally and brake fluid levels will show to be normal.

 

IMHO a leaky o-ring might end up as a leak at the brake actuator arm at the brake pedal. Might want to look down there for a leak.

Or I guess it could be leaking into the brake booster.

 

I would think in those instances, you would see fluid levels drop in the reservior no? Fluid levels are holding normal.

 

I guess if it leaked enough. I'm trying to imagine how the MC can have a leaky o-ring and not leak the fluid outside the system. Maybe the brake booster isn't up to par.

 

I also have increased pedal pressure if I "repump" it once. I never really thought of it as an issue, but this has me wondering. I have no problem stopping either.

 

I have bled the brakes and it made no difference. I did a full external inspection and no leaks at all. My fluid level has stayed constant all the time.

One thing i notice if that if i'm stopping (or in park) and spend 5 mins mashing the pedal as hard as i can and letting it up, it does make the pedal feel better for a while. It's still not great, but feels better. Eventually though it goes back to the same soft feeling. I've just gotten used to double pumping during certain stopping situations.

I have read that others have this issue as well, which makes me beleive there is some sort of design flaw in the system that allows air to seep in (air is smaller than hydraulic fluid) or something else? But what.

Has anyone had the dealer do a bleed by cycling the ABS??

Still waiting to find someone say "I had the soft brake pedal issue, and i replaced part X and it fixed it"...but in all my internet searches i haven't found it.

I did find someone who said they replaced the calipers and it fixed it, but it was 1 case, and that's a very expensive fix.

 

I'm thinking one of the interior o-rings may have failed around one of the pistons. You wouldn't see any external leaks.

 

No one suspects the vacuum booster? Just a thought. Thanks for the pic deep. Makes sense