Pedal Engaging Low help!!!
 

Hey guys, I need your help. I upgraded my rotors, brake lines (to stainless steel lines), calipers (from base to sports), pads (to stop tech) and bled the brake lines 3 times. I can not get away from the pedal engaging low before the brakes are starting to apply. I have to push the brakes down 2 inches before they engage and will stop more the farther i push. I bled the system 3 times with a motive power bleeder at 15psi with Valvoline synthetic and got all the air out but did not bleed the abs module with a scan tool (I was reading that the abs module may have air in it). The brakes will stop fine once engaged, no lights are on on the dash. Master cylinder isn't leaking or anything. Is it necessary to take the car to a dealer for the abs module to be bled? The brake booster seems to be fine, I'm doing a psi test on it tomorrow, the rpms don't drop or anything when i push the brakes. I checked all the lines and there are no leaks. Also i got the calipers rebuilt and had to leave the brake lines off for a month while a waiting on my powdercoater to give the calipers back (this didn't help lol) :shakes head:, I'm not sure if air got into the module or what happened. Any help would be appreciated. The main problem I am having is that the pedal doesn't want to engage the brakes until it is pushed down 2 inches, almost all the way to the floor. The harder i push the pedal, the more stopping power i have

If you pump the brakes does it feel like it builds pressure?

If so you need to bleed them.

Also dumb question, But while you bled the brakes did you have the parking brake engaged?

With the car off it does build pressure. The parking brake was not engaged at all times

I bled with the motive power bleeder two times and one time I did a manual two person bleed

Yea, Somehow you may still have air in one the lines or the master cylinder needs to be bled also.

I would just make sure to not let the reservoir fall below half.

Did you install NEW or used Pads?

If used? The pads may need to be replaced.

If the ABS unit needs to be bled separately from the brakes, the procedure should be in the FSM.

They are brand new pads. I'll try a master cylinder bleed. The thing is that the car sat for a month with no calipers and the line dangling with all the fluid leaked out. It sat for a month with the reservoir completely empty.

I looked at my manual today but I believe it has to be bled in a sequence with a obd2 tool that I can't get over the counter.

Well, Thats as much as I can do for you. :tiphat:

Thanks for trying to help bro :tiphat:

Assuming it's not the ABS module (I've never heard of anyone having to bleed the ABS unit on a car, but I'm no expert), it sounds like air somewhere. But you seem to have enough mechanical aptitude to bleed brakes properly, so that's probably not it.

The only other thing I can think of is that maybe a piston seal in the MC was damaged when the system was empty.

The FSM usually has diagnostic procedures for troubleshooting. But they often require the use of Nissan's software (I forget what it's called). Worth taking another look.

Thanks bro, I'll check again in the service manual

Still no luck lol, I'll check the booster tomorrow again

Bleed the Brake MC. You got air in it somehow. Ensure you don't have any lines loose that are sucking air.

I'm gonna try that today, any ideas on how to do it without taking it off the car?

You don't have to remove anything from the car.

But under or on the side of the brake fluid reservoirs there should be two bleed screws one is for the front and the other for the back.

Im sure Youtube has someone showing how to bleed them.

But it's the same as the wheel calipers.

If there's no changes you have a stuck brake piston in one of the calipers worst case scenario or try adjusting the brake pedal, The rod that goes to the master cylinder.

Im sure adjusting it will give you more pedal travel.

The switch from base to Akebonos might impact the overall pedal travel.

Im speculating here.

I have been checking on my sport 370z and the pedal is adjusted the exact same. I'm thinking about unscrewing the two screws like you said and trying to connect the lines to there and having someone push the pedal to bleed. My only concern is when I disconnect those lines, WILL it make more air go into the abs module? Or make this worse? By the way, I opened the master cylinder cap and there is some black stuff at the bottom like tiny trash particles and also there were bubbles all at the top.

All right disregard what I just mentioned about bleeding the MC :facepalm:

I went out and physically saw there are NO bleeder screws but the low fluid connector.

Sorry!

What about the bleeder screws on the bottom of it? I thought those would work??? There are two that go from the abs module to the master cylinder. I think those are the bleeder screws bro

Was looking at Ak's DiY and he mention there are two bleeders on the brake calipers.

one is outer and the inner? Did you bleed both?

http://www.the370z.com/brakes-suspen...17-ak370z.html

I did bro

ugh

All I can suggest it one last time to bleed it old school with a friend pumping and holding while you crack the valves making sure the reservoir stays full.

Also looked at the fsm and its pretty straight forward.

http://www.nicoclub.com/FSM/370Z/Coupe/2013/BR.pdf

Thanks for the help bro. I'll keep this thread updated as I figure out what's wrong.

Just have someone press on the brake pedal and hold. Then loosen one line. You will know if you have air in it. Do it again for the other line.

I will bro I'll try it all again

Last time I cked the E-brake is cable .. And drums inside.

I'm gonna try bleeding the master while its on the car. I am just worried about getting air in the abs module.

It won't happen if you do it carefully. Just do one line at a time. Front and then rear. After that re-bleed at the calipers again.

Hey guys I got an update!! I went by my friend's shop and he pulsed the abs module to get all the air out of it. Instantly the pedal felt better. I went home and bled the brakes with a power bleeder and A LOT of air came out of the lines. I drove it and it feels much better than it did, but not where i quite want it yet. I'm gonna stop by his shop again tomorrow and hopefully he can pulse the abs module one more time for me and hopefully it will fix the issue, but the pedal is engaging much much higher. He also told me to bleed the brakes manually when he gets done pulsing it again instead of with a power bleeder. He said that it is procedure.

update guys!! Got the abs module repulsed and manually bled the brakes and the car is engaging the brakes as soon as the brake lights come on!!! My 2014 (factory akebono, no brake upgrades at the moment) is more sensitive on the pedal but they both have the same stopping power so i am pretty sure i am in the clear. All the air is out of the lines and I am guessing the difference in the pedal is from either the conversion from non sport to akebono on this car or from the drilled and slotted rotors with stop tech pads.

The difference in the brake pedal feel is in the calipers. You went from 2 piston (?) to 4 piston in the front. That's a lot more piston area. And you didn't change the bore size in the master cylinder.

Yea true, but they are both working the same now. I thought the master cylinders were the same?

The master cylinders in the base and sport are the same, I just confirmed that

Hydraulic's 101. When you change one end of the system and not the other to match. Of course you will get different a pressure. The master cylinder may be the same. But what I'm getting to is the reason for the different feel. Throw in the electronic ABS. That changes the brake feeling too. Give you a question. Think about it. How many different things you can think of, that will give you a different feeling of the brake pedal?

I'm still not sure what you mean. My sport 370 came with akebonos, my other car I did a conversion on and it has the exact same setup as the sport and doesn't have the exact same pedal feel, most likely because no two cars are alike. The pedal on both cars are very very similar now though. Thanks for the help again Rusty and everyone else!

What I was getting at. What things that can make the pedal feel different. Different pads, miles on pads, rotor material, brake lines, brake fluid, ABS, air in the system, different shoes, going from a soft tennis shoe to a stiff work boot, or anything in between.

How many things did you change, mess with when you did the change over? All of this is food for thought. Teaching you how to use your noddle. :D

I didn't think about that. I put stainless steel lines on it, r1 concepts drilled and slotted rotors, stoptech pads, and flushed with Valvoline fluid. That's a lot more than a stock sport z came with so that could explain the pedal feel difference.

OP - did you get this resolved?

I remember on my BMW I did not have access to a tool to bleed out the ABS lines when I replaced the ABS module - so I had to "manually" do it...i.e. depressing the brake hard on a "wet" surface to engage the ABS a few times....that got the air out quick ;)

Thanks man, and yea I got it resolved! Abs module had air in it and now it's all good