Soft Brake Pedal
#106
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G35 sedan w/ too much money in mods
#108
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G35 sedan w/ too much money in mods
Jeff are you asking me if that's possible or if I will do it myself and report back? I can tell you that last week I used a baster and removed enough fluid to get the level just above the full line and the feel was noticeably softer than with the level where it is now. Not a huge difference but enough to feel. I would have to assume that as you remove fluid from a full MC the feel would get softer the more you removed based on my experience.
As far as the level, you're absolutely correct that someone with half worn pads wouldn't want to fill it completely unless they are willing to extract a good amount on their next brake job. For me it isn't an issue as my pads were brand new at the time.
As far as the level, you're absolutely correct that someone with half worn pads wouldn't want to fill it completely unless they are willing to extract a good amount on their next brake job. For me it isn't an issue as my pads were brand new at the time.
#111
#112
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G35 sedan w/ too much money in mods
#113
well I think I figured out my problem today.
I was working on the car again and planning on bleeding the brakes for the 4th time (in accordance with the service manual) and I noticed on my passenger front caliper the clip that pushes the bakes back was jammed in on one side. so instead of slightly removing it from the rotor, it was pushing against the pad.
got some pliers and pulled it out and bent it back the way it was supposed to be going. bled it one more time for the hell of it and just did some test pumps in the car and it seems a lot better.
car is still in the air (on jackstands) so I can't say its fixed yet but it sure as hell seems like that would be causing my issue.
I was working on the car again and planning on bleeding the brakes for the 4th time (in accordance with the service manual) and I noticed on my passenger front caliper the clip that pushes the bakes back was jammed in on one side. so instead of slightly removing it from the rotor, it was pushing against the pad.
got some pliers and pulled it out and bent it back the way it was supposed to be going. bled it one more time for the hell of it and just did some test pumps in the car and it seems a lot better.
car is still in the air (on jackstands) so I can't say its fixed yet but it sure as hell seems like that would be causing my issue.
#115
I just read this thread after flushing my brakes with a motive bleeder (at ~8-10 psi if you are curious) and used prestone DOT 3 fluid.
My pedal was sometimes soft before, but the fluid was so old it just didn't have a good pedal at any time (05 G/93K/OEM fluid). BTW, I'll be flushing one every year or two, my old fluid was brown, and the initial bleed from all the calipers had this white junk float out followed by bits of black for a second or to. Yeesh.
Now it's noticeably soft on the first push, then firms after. It feels great after. Basically, the issue the OP has.
I bled RR, RL, FL, FR. I know this isn't the FSM procedure but I could only get two wheels in the air at time. I also didn't not disconnect the VDC/neg terminal.
My 02 Altima had this problem, but reverse: It would be very soft but occasionally get firm.
I will be living with it for now and watching my fluid level to make sure I'm not leaking somewhere and introducing air.
EDIT/UPDATE: For the first time tonight the car had good pedal, this was the third or so driver after the above bleeding was done. It was significantly cooler than it has been and the pedal was not soft for one time the whole night (~30 miles of driving). I may try bleeding again at my next oil change. There were a few tiny bubble that came out of the rear calipers near the end of each flush.
Vacuum bleeders: I don't recommend guys using these continue to do so. I know there a fellow a few posts up who using teflon on his bleeders thread for a better seal but the theory behind it is that air can still be sucked in. I think the two-person method or powerbleeding is the only way to ensure you won't introduce more air into the brake system.
My pedal was sometimes soft before, but the fluid was so old it just didn't have a good pedal at any time (05 G/93K/OEM fluid). BTW, I'll be flushing one every year or two, my old fluid was brown, and the initial bleed from all the calipers had this white junk float out followed by bits of black for a second or to. Yeesh.
Now it's noticeably soft on the first push, then firms after. It feels great after. Basically, the issue the OP has.
I bled RR, RL, FL, FR. I know this isn't the FSM procedure but I could only get two wheels in the air at time. I also didn't not disconnect the VDC/neg terminal.
My 02 Altima had this problem, but reverse: It would be very soft but occasionally get firm.
I will be living with it for now and watching my fluid level to make sure I'm not leaking somewhere and introducing air.
EDIT/UPDATE: For the first time tonight the car had good pedal, this was the third or so driver after the above bleeding was done. It was significantly cooler than it has been and the pedal was not soft for one time the whole night (~30 miles of driving). I may try bleeding again at my next oil change. There were a few tiny bubble that came out of the rear calipers near the end of each flush.
Vacuum bleeders: I don't recommend guys using these continue to do so. I know there a fellow a few posts up who using teflon on his bleeders thread for a better seal but the theory behind it is that air can still be sucked in. I think the two-person method or powerbleeding is the only way to ensure you won't introduce more air into the brake system.
Last edited by AuAltima3.5; 04-16-2011 at 10:31 PM. Reason: Update
#116
I drove ttrank's car solo
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G35 sedan w/ too much money in mods
#117
Has anyone every changed their mc? Its too expensive of a part to do on a hunch, but other forums I am on suggest this as the primary culprit. However, it's a $200+ part so I am wondering if anyone has changed it due to a soft pedal and noticed improvement?
Im really sick of double pumping when I come off the highway to get a good pedal.
Im really sick of double pumping when I come off the highway to get a good pedal.
#118
#119
#120
But was there an issue with your brakes before? The thinking is there is a defect in the MC allowing fluid to leak past the internal seals.
I've bled gallons through the system. Nothing makes a difference. I'm at the point where i'd like to start changing components but really don't want to throw random $$$ unless i have a good idea of the cause.
I'm very familiar with brake systems (installng custom brake kits, reflaring lines, installing different MC's to match calipers, etc), but this one has me puzzled.
I mean at this point, i'm so used to it it doesn't really matter