BlueSQ

I was performing a brake pad burn in on a well worn set of brake because I read doing so can eliminate built up brake pad material on the rotor. Got the rotors warmed up then started the 8-10 passes of 60 to 15 mph. As I got on it I noticed there was no ABS. Eventually by the 3rd or 4th pass I gave the brake pedal everything my foot could give it, so pretty much standing on it. There was no ABS, not even a hint of it.

My concern is either the ABS system is not working or I have an aftermarket rotor/pad setup that is not jiving with the enthusiast model calipers in that even at full pressure there isn't enough clamping pressure to lock things up. Obviously locking up the rotors isn't desirable but the absence of ability to do so is concerning.

Thoughts?

karlt

You answered your own question. If you're not locking up the wheels, ABS will not intervene.

What exactly is your pad/rotor setup? And how old are the rotors?

BlueSQ

Not sure, a buddy who works at a German auto shop supplied and installed them, said they're what he uses at his shop for BMWs. He did mention the pad and rotor both are made of very hard material, likely harder than whatever OE for the Z is.

The pads and rotors are 3 years old and probably have about 30,000 miles on them.

iideadeyeii

iTrader: (6)

I've had eBay pads before that caused the same issued you're having.
Switch to cheap semi-metallic pads from an actual parts store.

jhc

If your brake pedal goes to the floor you need professional assistance. 02.

BlueSQ

I'm curious about this. Is this because the pads and rotors I have aren't right for the size and clamping pressure of the stock caliper? They're definitely not cheap parts but the cars they go on likely have stronger calipers than the Z.

I did a search for this specific issue and came up short.

BlueSQ

You're right I did say "floor", I probably should not have. It doesn't actually hit the back of the foot well. It's just me fully pressing the brake pedal, very hard until it won't travel anymore.

iideadeyeii

iTrader: (6)

It should lock up regardless. This happened to me on 2 different cars from pads I ordered online. Replaced with cheap autozone semi-metallic and it fixed the issue.

BlueSQ

That's great that it was solved by going with a less expensive option.

When you ordered online, did you buy sintered metal pads? The reason I'm asking is maybe it's the switch from full metal to semi-metallic organic that fixed the issue. They work differently to achieve friction.

iideadeyeii

iTrader: (6)

The online ones were "ceramic". My audi pulling my 2,000lb trailer almost couldn't stop off an exit ramp because they barely worked. Swapped to the autozone cheap pads and pulled 4,000lbs in the city no problem with stopping.

The car had new fluid/rotors also.

BlueSQ

Sounds like semi metallic or organic is the way to go with the stock Z braking system with smooth rotors. Kinda surprised I haven't seen more threads like this. Maybe I just used the wrong search terms.

BlueSQ

Thinking of going with Akebono slotted rotors and Hawk HPS pads (Ferro-Carbon compound).

That sound about right?

zakmartin

I've gone with Hawk on my Z and hated them; I changed them out after about a month. Centric Cryo-Treated rotors and the Centric Posi-Quiet ceramic brake pads with shim kits are awesome for daily driving. I'm in a super-hilly neighborhood and the Centrics have never let me down.

JMII

I got the Akebono's (with slotted Centrics) and do NOT like the Hawk pads, read why here:
https://my350z.com/forum/brakes-and-...l#post10908738

I run EBC Yellow pads these days and they preform great. Ran Blue for track days but they are too dusty for a daily driver pad and need some heat to really grab well.

Using all stock components you should be able to get into ABS pretty easily. It may not be how hard you press (IE: to the floor!) but how fast you get there. If you press down hard but too slowly (note: it may seem fast to you) the car will slow progressively without every reaching the lockup threshold. You would might be shocked at just how fast and firm you must be to reach ABS especially on a good surface. On a wet surface it will be much easier, but I don't recommending testing your ABS that way since you could lose control completely. I instruct at track days and my students are amazed at how hard you can brake and still have room to spare. Very few students get into ABS despite carrying way more speed then you do on the street.

other ideas: might be a tire issue, IE: the tires grip so well they don't skid. Or maybe by heating up the pads you might have actually over done it and glaze them over or could be getting some fade. If you got air in your brake lines from getting them really hot (air = boiled fluid) you will not be able to get the full force into the calipers (air can be compressed but fluid can't). As a result the brakes would be slightly mushy or soft.

BlueSQ

Interesting, that definitely helps. I'm on Michelin super sports so they're about as grippy as they come for a street tire. The brakes are due for changing so it's just a matter of what to get and if maybe my pad/rotor setup simply isn't compatible with the other OEM parts in the system. Again, these were supplied by a friend at a BMW shop, I'll hit him up to figure out exactly what he threw on there.

LiamGutierrez35

ABS will only activate if the wheels would otherwise lock up and stop rotating. If your wheels aren't locking up there is no purpose in abs activating as it would only reduce your braking.

BlueSQ

Yes but the underlying issue is why don't the brakes clamp with enough force to lock the rotors on demand? If I depress the pedal fully and quickly in 'emergency' style braking the calipers should work with the pads to seize the rotors and therefore engage ABS...at least it does on the OEM equipment. Or maybe I'm interpreting the lack of ABS erroneously as an incompatible match of brake pad and rotor materials to the stock calipers.

I'm curious, has anyone else experienced this after installing aftermarket brake components?

zakmartin

If you can't lock the brakes, then I'd start by bleeding the brakes properly, with a positive pressure bleeder like this one:

https://www.motiveproducts.com/colle...-prong-bleeder

You're not going to get enough fluid through the system using conventional methods of bleeding (brake pedal pumping or fluid vacuum pull). Positive pressure bleeding is really the ONLY way to properly bleed the car's brakes on the 350Z. Unless you do it this way, you're not going to get the pressure you need.

If you have tried this and your brakes are still sloppy and don't lock when fully depressed, then you may be looking at a mechanical issue, either with the master cylinder, caliper(s), ABS actuator, lines, etc., etc.

BlueSQ

Awesome info, thanks. I'll have the shop do this when they swap the brake pads and rotors. I watched a how to on this, seems straight forward.