Nobody have any idea over here? Have to go to dealer in 1-2 weeks... Will have them check. No leaks.

Having a little pulsation pedal ( rotor went realy hot while hauling and towing firewood, and went into water on the road :-$) still more than 50% brake pad everywhere.

 

If you're sure you have all the air out then your master cylinder is bypassing. change it out next.

 

He already checked it and said it isnt bypassing.


Im just going to throw a few things out there....
You supposedly need to disconnect the ABS or pull the negative battery cable according to the FSM when you bleed. Did you do that?

Is the braking itself soft... ie: not very grabby? If you generated enough heat to warp your rotors, you likely have glazed pads too. This results in soft braking. Some sandpaper on the pads will clear the glaze.

Since this seems related to some random brake application, I would also suspect something wrong with the ABS system.

 

Take it to an independent mechanic, not the dealer...unless it's still under warranty (2011)

 

Sounds like an ABS or traction control issue to me. Brakes applying without you pushing the gas pedal is bad juju, and smacks of traction control freaking out over a bad input. In aircraft, uncommanded flight control movements are painstakingly investigated. This should be as well!

 

i changed my pads and rotors and my pedal is spongy as **** now. i just live with it.

 

You have me out of thoughts. I'd suspect I am not the only one.

You didn't mention any prior leaking or missing fluid, so if the master cylinder is always full and dry, and you've bled the brakes to death, then I am at a loss. Like many here, I have a good working idea of how a hydraulic brake system works. There are only so many trouble variables. If its full of fluid, has good vacuum to the booster, lines are air bubble-free, no sticky calipers, and not leaking fluid, then I am at a loss.

My only questions-- when you bled the brakes, was it a 2-man job, or did you use a pressurized bleeder pot? Was the old (2011 "old") fluid just as clean as the new fluid? Water-free? Have you inspected behind the brake pedal, behind the carpet along the firewall, to see if anything is abnormal? No fluid, no obstruction of brake pedal rod movement thru firewall? Have you ever replaced any component of the braking system? Sorry I am of no help & good luck, and please post the fix findings so that I can say "I should have known that".

 

Have you bled the brakes according to instructions for ABS? Seems you have an ABS issue.

 

Re-bleed again today. Now I get a half way better feel. But no air seen on any caliper ?! Did it because I didn't disconnect abs/bat. negative last time.
Never miss fluid, no leak in any way, never lost fluid. Yeah, rotor are a little spotted, but when I use brake, after the first soft part, I have a good grip, and if braking firmly then pumping 1 time, I get a full pedal and a nice grip.
Will use it for weekend, then bleed again next week.
Did a 2 man bleed. I saw something over net and will try this: between each opening, givint the system to set back 15-30sec is something needed on some cars. Would like to use power bleeder, but cannot find any near my place and always got nice results on older cars in the past with 2 man bleed.

Thanks for all info. Yeah truck is under warranty. 7years/140000km. Extended... But wanna eiminate all "air" or bleeding trouble since i'll have to pay $$$ for something I can easily do at home. If trouble stays after several good bleeding, i'll put dealer on it. Ant will tell about trouble I got. Never did it again :-( but will be in file.

Old oem fluid was darker afetr first bleed, but no white color, sign of water or bubbles into it. Clear but darker. After second bleed, I got a light darkening beside new fluid, but hard to see. And no difference today.

I was thinking if a trouble into ABS or VDC system, or a wire harness relative to that. Got the car washed in the morning before that happened... Engine bay too to remove sand/salt.
Maybe a bad contact? But never did again.

I was also thinking of a bad pressure valve (there is a system that keep residual pressure into brake system no?). If so, the trouble could be that I've to rebuilt pressure before having a good braking? Pads went farther than normal when not using brakes?

Will see what I get this weekend. Got alot of info over here, ThenewX, google and now from this post. Nice to get help!

 

Not my truck, so dont ask me how that conclusion was gathered. He said it isn't bypassing and I have to take it at face value. dont shoot the messenger

 

finally, after bleeding brake lines more than 20 times (yeah i'm crazy i guess), and changing more than 6 litres or fu##ing brake fluid, i didn't get any improvements.

BUT after replacing my rotors and pads, what did bring me that spongy feel, I GOT MY PEDAL BACK ALMOST LIKE BEFORE!!!

Don't ask me why.

What I believe: our brake system compensate for poor braking, and over assist till we get something. Since I've correct braking parts, system stopped doing that stupid thing, or something like that.

Was it air into MC ??? I guess no. Why? because I already squeezed my caliber cylinder all in to try that possible troubleshooting, and never got any improvement.

From a thread I remember, Brutal told that when working on cars at work, he sometimes see bad brake components, even into good fab. Maybe I got one of them.

This is how trouble ended for me! Nice day to everyone!

 

I think that shows mt.aero was right: glazed pads/rotors.

See, in a system like the frontier which has a crazy amount of leverage so granny can lock up the tires without upsetting her arthritic hip and artificial knee, you never really have to exert much actual pressure so all you notice is the travel.

It's not that the truck assists when it notices bad brakes, it's that your foot pushes until your brain gets what it wants (deceleration). combine with the leverage above and it feels like a dead pedal that needs to be bled rather than pushing hard with no effect.

 

I am in the same boat like many others here. Several years ago I replaced my brake lines with SS lines, new front and rear pads and all new fluid. Since then pedal goes half way down and then engages. Lately it does not seem that abs is engaging. I have even adjusted the pedal height at the master cylinder. After replacing with OEM pads, there was about 30% improvement. I am now thinking that there may be air in the ABS system. I bled it according to manual.

1. Any Ideas?
2. How to get air out of the ABS system? Do I have to take it to the dealer? or should I replace all rotors, pads with OEM and then try?

2005 Nismo KC with manual transmission.

 

i was able to drive quickly on my rock driveway to engage the abs system. i parked it and unplugged the abs and then bled my whole system and my pedal is firm as **** now and braking power comes on within the first 1inch and stays firm i just apply more pressure. ive never adjusted anything on my actual pedal or master. just bleeding.


as you can see my previous comment my pedal used to damn near go to the floor before the truck wanted to stop. these systems i really think are just prone to getting air in them.

 

Hi Andy: I think you are correct. Very finicky. I disconnected the battery when I bled it last time, so this time I will bled the system after I disconnect the abs plug. I wanted to before but I think either it was in a awkward location or I had a option to disconnect the battery negative terminal and I went the easy route.