Hello,
First time here on forum. I have a 2005 G35 sedan, purchased new and have been doing all the service myself. Since the change of rear brake pads 5 years ago, the car never stop the same. It doesn't have the neck snapping feel anymore. Let me provide the service info.

2005 Purchased new
2010 60K mi, rear pads worn (evenly). Replaced rear with new OEM pads.
Front rotor and pads looked new and thick.
After replacement, car lost it superiors stopping power. Brakes were bled 2X with no improvement. Still feel like air in the system.

2015 100K mi. Car shakes a little when slowing down around 30mph.
Replaced worn rear pads with new OEM. Still have about 30% left but decided to replace anyway.
Front pads still even and thick. Look at as good as when I last inspect 5 years ago. The rotor is nice and even. Decided to replace the front rotors with new OEM.

Inspected rotors, pads, calibers. Everything seem to be in good working order for front and back. The brake feel is soft and I can feel the bottom when fully depressed. On dry pavement, I can hardly engage the ABS.

Question:
Why is front pads still thick? It seems like the front pads are not working at all therefore still thick after 10years.

I have read somewhere air may have gotten into the ABS module. Any advice in how to fix that? If other components are failing, please give me advice where to start troubleshoot. Last thing I want to do is bring to dealership and let them change the entire brake system.

Thanks in advance.
007

 

You can bleed that out through regular bleeding methods.



Let me ask you this. With the car turned off, if you pump the pedal a few times, does it get rock hard? Stand on it and it won't budge? If it doesn't....you have air in the lines still somewhere. Bleed again and if possible try another method like vacuum bleeding.

When you open the bleeder, does fluid squirt out in a strong stream?

If you've gone 100K miles without wearing the front pads, i'd suspect something is wrong up there. These cars are prone to having caliper pistons seize up, so perhaps 1 piston on each side up front is frozen in place.

Can you remove the front calipers and push the pistons in with a C clamp? They should move pretty easily. If there is enough resistance that you feel like you need to clamp hard on the c clamp, then perhaps that piston is seizing in the bore.

I've run into this soft pedal issue on my car at two separate times (over the course of 160K miles) and the issue was always caliper related. In my case, the rear caliper slide pins would seize in the bore causing the caliper to lock in place and only press on the rotor from one side. This is a pretty common issue so you will want to inspect the caliper slide pins on each caliper and confirm they all move freely. However, if you got nice even wear each time you replaced the pads, then this might not be the case.

Also, I have 160K miles and still on my SECOND set of rear OEM pads. I will need to change them to the 3rd set soon. Sounds like you went to the 3rd set at 100K mile, while still on original fronts. I'm on my 4th set of OEM pads up front. Sounds like you need to investigate the front pads for sticking pistons, or a fluid blockage. Sounds like all your braking power is coming from the rear.

 

Mustang5L5,
I am sorry for the late reply...busy with work. Thank you so much for your advice. After bleeding over the weekend, the car can finally able to stop on a dime. I can hear the tire screech and the abs activated on drive pavement when I slammed on the brake at 20MPH. That totally was not possible before.

This time I followed the G35 FSM bleeding instruction.
1. pump few times and hold down position, released the bleed bolt
2. tighten release bolt once brake was fully depressed.
3. Repeat for about 10 to 15X.

Previously, for the last 20 years, we have been letting the bleeding bolt loose and continuously pump 10 to 20 times. Air must have got back in when brake was released. Don't know why it worked for the previous cars, perhaps they didn't have ABS.

In addition, we also followed the bleeding order of the FSM instead of the traditional method which starts from the most far brake and work your way closer.

I think this is the order FSM provided:
1. passenger rear
2. driver front
3. driver rear
4. passenger front
https://g35driver.com/forums/brakes-...procedure.html

Once again, thank you for your help and now I don't have to worry about my family riding on an car with unsafe brakes.

007