Hey everyone I am trying to get the brakes back in my 350z.

Short story. Stripping the car for a cage. I have been chasing a brake issue for a little bit. Its a 2003 VDC car that has been converted to Brembo calipers. I was chasing a dropping to the floor issue on track. With 213k miles some thought it was a master issue. Anyways pulled the master and there was some signs of leakage. However talking to a few people who have had base cars but went to Brembo calipers they went the bigger dual stage booster. They were having the same inconsistent issue. Both had the issue go away with the bigger booster. Since my car had no interior I decided to do a Brembo booster. After two used ones (one was damaged in shipping, one was wrong (non vdc)) I bought a reman from work.

Last weekend I put the new booster in. I used the good looking master from the damaged in shipping booster. Got the air out but the fronts seemed weak. Pedal also dropped to the floor with the car running. So ordered a new Raybestos master cylinder. Swapped that in today. Bench bleed like I always have with other master cylinders. Pressure looked good. Had a good stream coming out while i was hooking up the lines.

Bleed the system back out. Got some air but was expecting more. Took a while to get the system to start pumping some fluid around.
Decided to hook my the scan took I bought from Z1 after the first round of bleeding. I cycled the abs pump for a good 20 seconds. Bleed the driver caliper but no air came out. Decided to go where I could cycle each solenoid. Opened and closed them a good 10-15 times. Each cycle was about a second. Got loads of air out of the right rear and front right. Drivers rear got some air. Zero air out of the front left. Cycled the pump some more as well as the front solenoids. No change. Rain was coming so put the car on the ground. Tried moving it and the pedal sinks down just like the other used master. Parts quality is junk these days so I could have another bad master....I mean I warranty many of our masters out.

Pedal feels better than the used master but its still not good. I have had no issues bleeding the brakes on this car before. I have done stainless steel lines, repaired bleeder screws on 3/4 and even had to swap the front calipers. Every time it was a super easy bleed. One trip around the car and we were done.

So that being said is there a special way to bleed the brakes on these cars. I know my C5 z06 has an abs bleed cycle that activates the pump. You open the bleeder valve and pump while the abs is active. Debating trying that tomorrow before I load the car onto the trailer to go to the cage shop.

I have the scan tool from z1. I can activate the abs and let it run. The solenoids only seem to run for 1 sec. I could not find an abs bleed setting. Am I missing something?

 

Sounds like you've tried to be methodical and thorough in going through your braking system. But you've also replaced a lot of components in the process, and my bet is you've still got some air stuck in there. Where? I can't say, If I had to guess, I'd recheck those repaired bleeder screws on 3/4 and refill my gumption tank before going through the process once again. These braking systems are not easy to bleed when you've got them apart, so get that cheap DOT 3/ fluid out and keep at it until that pedal firms up. It may not be perfect, but once your cage is done and you get the chance to run some installation laps, a little heat (and more bleeding) usually gets the last of the air out. Good luck!

 

Well hopefully got it solved. The front line was a leaking a small amount out of the master when pushed really hard. Bleed everything again, this time just side to side. Calipers have movement like they should. Pedal does not the best but it seems to work. Not sure I like this new booster. But we will see. I am going to do a quick run down the side street before it goes onto the trailer as I can only move the car 10 or so feet as its blocked in by the trailer and truck.

But time for that cage. Its only been three years in the making. 135 on the back straight of Road Atlanta or Watkins Glen in stock seats is getting a little sketchy. Shoot was even doing 133 at Roebling. I have had the seats and belts sitting here a year and a half now.

 

When running the Brembo front calipers, you need to remove the top mounting bolt, loosen the bottom bolt and tip the caliper forward so the bleeder screws are nearly vertical (perpendicular to the ground), while also keeping the brake pads in contact with the rotor. I had this exact same issue when I 1st installed Brembos on my Z. The factory mounting position has the calipers swept back considerably, causing air to get trapped around the pistons.

Try this out and I bet you immediately get air out of those front calipers.
Cheers!
-Icer

 

Anytime I’ve gotten air in the abs unit, it takes a pressure bleeder and multiple days to get it out

 

As far as a special way to bleed the brakes, the FSM states that the order of bleeding should be rear right, front left, rear left, and then front right. Not sure if that makes a difference or not. It shouldn't, but who knows. I only mention it since it's not the conventional order of bleeding starting with farthest away and working your way towards the master.

Also, IIRC, with the two bleeders on the Brembo calipers, you do the inner valve first, and then the outer. Icer has a good tip to rotate the assembly so air rises to the top where the bleeders would be. Also, a few taps on the calipers while bleeding will help dislodge any stubborn bubbles.

Are you doing the pedal pump method (with valve closed, pump pedal 4-5 times, hold brake pedal down, open valve to let air out, tighten valve - repeat) or do you have a pressure bleeder (I.e., Motive)?

 

Ouch, yeah if air gets trapped in the ABS unit, your best bet is to get a bi-directional OBDII tool and pray there's a special function for activating the pump for each corner. I have used this function for a 2013 Toyota Prius, which uses an electric brake booster vs. traditional vacuum booster (main difference is the amount of fluid circulated per cycle). It worked fantastic in that case. But I've never tried this option on the Z, mainly because I have a Motive power bleeder which also does a great job.

I will say this though, even when using the Motive bleeder, I wasn't able to get all the air out of the front Brembo calipers without the "tilt" forward trick.

Cheers!
-Icer

 

Yeah, Its funny as even swapping calipers I have had no issues bleeding. I had to swap the fronts before Road Atlanta in December because my passenger side had seized up. I did not even bleed the rears out and had good pedal right away. I have had the fronts off a few times in this car with zero issue bleeding with them bolted on. But I will keep this in mind. The car is at my buddies place for the cage. So its going to be a month or so before I get it back. But shoot I had to do this repair on three of my bleeders. Got good at it



Yeah good Z buddy said if he gets air he goes and gets the abs to cycle on the street then comes back and bleeds again. My car does not have a tag since its just a track car. I think air got in through the lines that came off at the ABS pump. I had to take those off to get the booster out of the car.

Pedal pump method. I was following the FSM order. But at least the one in all data said outside bleeder first. Which is what I have always done in the past without any real issue. I do not have a pressure bleeder. I have used them in the past without any success so I have not bought one.

Yeah I was using the Z1 scan tool to activate the abs pump and I would get some bubbles out. I will allow me to cycle each unit but its only one up and down at a time. Not a constant pulse. Might look at my brothers fancier scan tool and see if it will do it. Maybe I bite the bullet and get the Motive Bleeder.

But the car is going to be gone for a month or so. Its getting a roll cage so I won't be able to mess with it till I get it back. Probably in March. Said 4-6 weeks.