So I have a G37s coupe, 2008. I have a problem with my brake system which even the Infiniti dealer could NOT fix.
Three months ago I have changed the brake pads by myself, but mistakingly instead of replacing the brake pads with the right way, I OPENED all of the four calibers a part and most of the brake fluid came out of the system, which I know I should not do. later when I put the calibers parts back togather and test drive the car, the brake pedal goes all the way down almost to the floor. but the car does stop. I already bleed the system from air and changed the brake master cylinder but the same thing is still happening.

so what do you guys think I should do?

 

Sounds like you're not done bleeding the system. Do it again sequentially following the steps outlined in the FSM. Bleeding hydraulic systems can take a lot of patience, especially when the hydraulic system has been opened.

Also, verify you don't have any existing leaks. Look very closely at the piston seals on the calipers. They may have been damaged if you disassembled them.

 

I actually went to the dealer and they blessed the system. There is no leaking, I would have to check the pistol seals as you said.
Thank you so much

 

Holy water doesn't work well in braking systems.

No dealer worth their name would release a vehicle with something as serious as a fault in the brake system without giving you an estimate of repairs and having you sign off declining the repairs.

What does it specifically say on the invoice?

You need to get this addressed immediately before you cause a wreck!!

 

There's also the ABS that needs to be addressed if you replaced the MC, never replaced my MC but I've read that that also requires a bleed if the MC gets too low in fluid or the MC is replaced.
Sounds like there's still more to be done w/ the bleeding. Might try a Nissan dealer.

 

^^Agreed. Dealer has proper tools to bleed the abs unit. I haven't looked up the section in the fsm, but most cars require the abs to modulated for proper bleeding if there's air present in it.

 

Beginning to feel we're being trolled.

 

^^Trolled with pistols and holy water

 

It's not quite the caliber of a true troll, but the communication does seem off a bit.

 

Yeah the dealer wants to replace all the four calipers, but I know that calipers won't go bad because of that. They did not ask me to sign anything, they said atleest the car stops

 

When I replaced the MC I just did the normal bleeding for the MC and the brake system, I would have to read more about the ABS bleeding

 

^^Wow... I did a short stint as a service writer years ago. A car in such condition would be considered unsafe by our shop. We'd never let the car go without the owner signing off and acknowledging they are aware of our warning.

 

If dealership bled your brakes and your pedal still hit the floor then something is wrong with your calipers. Something to keep in mind is the seals will require replacing every time you break them apart. Please refer to pg.41 with all the (X) marks which symbolizes replace after each disassembly. Hope this helps.
http://www.nicoclub.com/FSM/G37/Coupe/2008/BR.pdf

 

sounds like the caliper piston seals may be leaking fluid pressure causing the low pedal. check to see if those piston seals are available to be replaced by themselves. otherwise you may need to buy a complete caliper. lesson learned the hard way, if you don't know what you are doing keep your hands off it.

 

I just opened the front left caliper last night, and yeah the seal between the two parts of the caliper seems damaged a little bit, I but it up side down and closed the caliper again and bleed the system, then the brakes work excellent but a little oil leaking from that caliper. so as you said I should replace the seal. The problem is I could not find that specific seal to buy.