G37 Brake upgrade problems

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KrankyKoot
Posts: 10
Joined: Sun Jun 06, 2010 3:02 pm
Car: G37 6MT

G37 Brake upgrade problems

Postby KrankyKoot » Sun Jan 13, 2019 12:21 pm

Recently installed a full Stoptech pads and slotted / drilled rotors set on my 2010 G37 6MT. Except for getting the rear rotors off went fairly normal. Bleed the brakes then went for a brake seating ride using Stoptech recommendations. Pedal was a bit soft but came up with a pump. So I bleed them again this time disconnecting the ABS per someone's recommendation. During the bleed with my wife pumping the pedal the pedal went to the floor. Looked like the reservoir had fluid but filled anyway. Picked up a Motive self bleeder kit and bleed again. Got some pedal back but now had to pump a couple of times and if pressure left on the pedal it would go almost to the floor. After a lot of research it sounded like the master cylinder seals might have gotten damaged when the pedal went to the floor during the bleed process. So I changed out the master cylinder and yes I bench bleed the new unit. Now if have brakes that are almost useless. Have about half pedal and they won't pump up much.

Help! Anybody have any suggestions? Any ideas?


User avatar
telcoman
Posts: 5617
Joined: Sat Jul 08, 2006 11:30 am
Car: 2016 Q70 Bye 2012 G37S 6 MT w Nav 94444 mi bye 2006 Infiniti G35 Sedan 6 MT @171796mi. 2013 Altima 2.5SV
Location: Central NJ

Re: G37 Brake upgrade problems

Postby telcoman » Mon Jan 14, 2019 5:32 am

KrankyKoot wrote:
Sun Jan 13, 2019 12:21 pm
Recently installed a full Stoptech pads and slotted / drilled rotors set on my 2010 G37 6MT. Except for getting the rear rotors off went fairly normal. Bleed the brakes then went for a brake seating ride using Stoptech recommendations. Pedal was a bit soft but came up with a pump. So I bleed them again this time disconnecting the ABS per someone's recommendation. During the bleed with my wife pumping the pedal the pedal went to the floor. Looked like the reservoir had fluid but filled anyway. Picked up a Motive self bleeder kit and bleed again. Got some pedal back but now had to pump a couple of times and if pressure left on the pedal it would go almost to the floor. After a lot of research it sounded like the master cylinder seals might have gotten damaged when the pedal went to the floor during the bleed process. So I changed out the master cylinder and yes I bench bleed the new unit. Now if have brakes that are almost useless. Have about half pedal and they won't pump up much.

Help! Anybody have any suggestions? Any ideas?
Did it ever occur to you to read the BR chapter in the FSM for your vehicle prior to beginning the work?

https://www.nicoclub.com/FSM/G37/Sedan/2010/BR.pdf

Turn the ignition switch OFF and disconnect the ABS actuator and
electric unit (control unit) connector or the battery negative terminal
before performing the work.

BRAKE BOOSTER
PRESSURE SENSOR?

VACUUM LINES?

Telcoman

KrankyKoot
Posts: 10
Joined: Sun Jun 06, 2010 3:02 pm
Car: G37 6MT

Re: G37 Brake upgrade problems

Postby KrankyKoot » Mon Jan 14, 2019 9:32 am

telcoman wrote:
Mon Jan 14, 2019 5:32 am
KrankyKoot wrote:
Sun Jan 13, 2019 12:21 pm
Recently installed a full Stoptech pads and slotted / drilled rotors set on my 2010 G37 6MT. Except for getting the rear rotors off went fairly normal. Bleed the brakes then went for a brake seating ride using Stoptech recommendations. Pedal was a bit soft but came up with a pump. So I bleed them again this time disconnecting the ABS per someone's recommendation. During the bleed with my wife pumping the pedal the pedal went to the floor. Looked like the reservoir had fluid but filled anyway. Picked up a Motive self bleeder kit and bleed again. Got some pedal back but now had to pump a couple of times and if pressure left on the pedal it would go almost to the floor. After a lot of research it sounded like the master cylinder seals might have gotten damaged when the pedal went to the floor during the bleed process. So I changed out the master cylinder and yes I bench bleed the new unit. Now if have brakes that are almost useless. Have about half pedal and they won't pump up much.

Help! Anybody have any suggestions? Any ideas?
Did it ever occur to you to read the BR chapter in the FSM for your vehicle prior to beginning the work?

https://www.nicoclub.com/FSM/G37/Sedan/2010/BR.pdf

Turn the ignition switch OFF and disconnect the ABS actuator and
electric unit (control unit) connector or the battery negative terminal
before performing the work.

BRAKE BOOSTER
PRESSURE SENSOR?

VACUUM LINES?

Telcoman


Thanks for the info. Yes I did read the manual but after the install when I started to have problems. Not my first go around with brake replacements but first in a while. So more complex than expected with ABS, etc. Did the Brake Booster check process from manual and it failed but I do not have vacuum test tools. No test procedure for pressure switch that I could find. I get a solid pedal when engine off then goes almost to floor when started. It pumps up a bit but not much. Looking around those are symptoms are for air in master cylinder and there are a few bubbles showing under the filter in the fluid reservoir. I thought that I completed the bench bleed for the master according to mfg. instructions but there was not visual confirmation. They said when the piston became difficult to press than it was completed. Now i'm doubting myself again. Hate to have to pull the master.


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