Brakes don’t work after bleeding and new master cylinder
 

I have a 04 350z with a braking problem that I’ve had to deal with for a couple months now.

I broke a brake line out on the track which caused my master cylinder to run dry. I have since replaced the brake line, replaced the master cylinder, and have bled the sh*t out of the car using the 2 person method, vacuum bleeder, and pressure bleeder. None have worked that well, I can pump the brakes twice and I’ll have braking power, but without doing that I have very weak braking power to the point where it is unsafe to drive. Am I missing something? Any advice on how I could possibly fix this, I just don’t understand what is preventing my brakes from working properly.

thank you,
ryan

if you didn't bench bleed the master cylinder, this is a must before bleeding the brake lines. Should be some good videos on bench bleeding to make everthing a breeze. Also there is a brake bleeding sequence that you should follow. Its been quite some time and anyone correct me if i am off on this....
right rear
left front
right front
left rear.

If I use a pressure bleeder wouldn't that remove any air in the master as well as the brake lines, or do I have to separately bench bleed the master? Also, I've been taught the correct bleeding pattern is what is farthest away from the abs block which would be:
Rear Right
Rear Left
Front Right
Front Left

But again I'm also the one with the braking problem so that might not be correct.

Hey Ry,

Rusty is correct with the bleed order. This has to do with the ABS system, it's in the factory service manual should you doubt it. You mentioned you were tracking the Z, does this mean you're running with Brembo brakes? Or are you using the non-brembo floating calipers in the front?
-Icer

quick question. how did u break the brake lines on the track? were they SS lines?

power bleeder will not bleed the master, you have to bench bleed it. You can leave it mounted in the car to do it but will need help. You master should have come with a bench bleeding kit with instructions

Hey Ry,

Ok so if you're running the Stoptech brakes, then your calipers are mounted slanted back right? When you bleed the front calipers, you need to loosen up the caliper bolts and rotate the whole caliper body towards the front, making the bleeder valve as close to vertical as possible. This is a must! Having the caliper bodies tilted in their mount locations causes air bubbles to get trapped around the pistons. I'm running with the Brembo system and it also suffers from the same issue. When I first installed them I used a Motive Power Bleeder 3 times and still couldn't get a proper pedal feel. Only after I discovered this trick was I able to get all the air bubbles out and restore a rock solid brake pedal.

Here's a LINK to Stoptech's Z33 installation instructions. The details about the bleeding process with clear pictures are on page 20.
Good Luck!
-Icer

Wow I never would of thought of that. Thank you icer, I’m going to give this a try tomorrow!

Literally just had this problem,s when doing SS lines and rotors last week, I wish I saw this then lol. I just said **** it and spent 110 at the dealer. But the breaks are perfect now.

Hi Nill,

Yes this is a really common but not well known issue when running with upgraded brakes on Z33s (Akebono BBK, Brembo, Stoptech, Wilwood, etc). I suspect the majority of brake bleed related issues are because of this. I don't even think the factory service manual mentions anything about rotating the front calipers forward (making them vertical) when bleeding. I certainly didn't think about doing that when I was using a power bleeder, I just assumed all the air would get pushed out effortlessly. It was only after I did some heavy searching online that I discovered the Stoptech installation guide and read their notes about it. Sure enough, I tried that approach and couldn't believe how much air was still trapped in the caliper bodies. This has worked for me on two separate installations of the Brembo system. The second time around I had a perfect brake pedal after the first bleed session!
-Icer

Only because it hasn't been mentioned, if you're bleeding a BBK or OE Brembo system, each caliper will have an inner and outer bleed valve. Always bleed the outer half of the caliper first, then the inner. You might also try lightly tapping the calipers with a rubber mallet while cracking the bleed valve, which should dislodge any air bubbles from their nooks and/or crannies and send them into the rush of escaping fluid.

Take it to the dealer. its 100 ish bucks and it will be done right.

Typically whenever you let the MC go dry or you didn't bench bleed, a trip to the dealer is in order so they can use their consult tool to cycle the ABS properly to get all the air out.

Man that's a bummer. If air did get into the ABS unit, you're pretty much hosed fixing the issue at home. As mentioned, you need a dealer level tool (consult) to activate the ABS motor while power bleeding the system to flush out any/all airb bubbles that may have been introduced. Usually air bubbles won't get to the ABS motor from a busted brake line at the wheels, but if you replaced the master cylinder and didn't bench bleed it initially, bad things can happen.
-Icer

I tilted my calipers forward and actually got a lot of air out of the system. Still requires me to press the brake pedal half way down to get pressure, but a lot better then where I started which required me to pump the brakes twice. So many methods you have to try to get Z33 brakes bled its crazy! I'll try using a pressure bleeder and the 2 person method while the engine is running, hopefully that can squeeze the last bit of air out. Thanks everyone for their advice each time its getting me closer and closer to a rock hard pedal.

For reference, it took me 6 separate bleed sessions before my brakes were right. Though I'd had all of the calipers off at once. Keep it goin!

Another tip or trick that might help since you replaced the master cylinder. Get a small catch pan or some rags you don't care about. Put them under the master cylinder and crack the two brake lines that come off the master. Just crack them enough to get a slow drip of brake fluid. Are bubbles tend to get trapped here when you first connect the brake lines into a new master cylinder, even when it's been bench bled.

I've used this trick successfully on a master cylinder I replaced on a 99 4Runner. I had my Motive Power bleeder hooked up and pressurized, cracked one line at a time and sure enough I got a decent amount of air out before a steady drip developed. This is best done with a power bleeder instead of the two person method. You risk sucking air back into the lines when pumping the brake pedal, it can be done, but requires you to tighten and loosen the flare nut every cycle.

Hope you get your brakes back to normal!
-Icer