2009 Nissan 370Z: DIY Brake Pad and Rotor Change, Part 2
August 08, 2009
Midway through Part 1, we finished removing our 2009 Nissan 370Z's front brake pads and diverted you here. Now it's time to take the caliper off so we can get at the rotor. There's one simple rule associated with taking a caliper off for this purpose: don't break open any hydraulic lines!
In order to ensure that doesn't happen, the first thing to do is locate the rubber brake hoses and the hard brake lines and make a game plan. This is the first time I've worked on a 370Z, so we're learning this together.
Look what we have here. This is going to take some care, because a hard steel (and mercilessly controrted) brake line wends its way from the caliper on the left to the junction block on the right (white) where the rubber brake line joins in.
The rubber brake hose bolts to something rigid at either end (white) but we don't have to remove either of these bolts. And we can just barely see where the hard brake line from the caliper comes in (yellow). But we don't want to crack this open either.
The yellow arrows show the hard brake line we don't want to crack open, but it will have to be free to move as a unit if the caliper is to slip up and off the rotor. The big black bracket (blue) is the key. It holds a clamp for this hard line and, on the other side, the junction block for the rubber hose.
All three green bolts will have to come out.
They all have 12mm heads. It takes less than a minute.
That's the ABS wire. It slips out of its slotted perch with minimal effort.
That done, it's time to remove the two caliper mounting bolts (yellow). The whole caliper comes off in one piece, so the bolts you want are the ones that bind it to the hub carrier/knuckle. Don't even think of loosening any of the bolts that actually hold the caliper itself together.
The upper caliper mounting bolt required us to bend the hard steel line just a little to get the socket on. A little tweak between friends is OK. Just don't be tempted to take the line off.
Both bolts are now loose. As soon as this top one comes out I have to be ready to support the weight of the caliper (it's not heavy). Then, with the hose bracket already loosened, I can gently lift it up and off the rotor. I have to go slowly and shepard the brake line along with it, taking care to keep it from getting hung up and bent.
This is where a helper comes in handy -- two hands aren't quite enough. I need to hang the caliper close to where it was because the brake lines don't move that much. I like to hang it from the spring or upper control arm via zip ties that are chained together. A bent coat hanger works, too.
Whatever you use, don't drop the caliper. I'm hanging it by looping a zip tie through the uppermost bolt hole that was just vacated when I removed the mounting bolt.
The sixth bolt has almost no purpose, but it has to come out. Some cars use a countersunk Phillips screw that actually holds the rotor in place when the lug nuts are off, but that's not the case here -- it doesn't actually thread into the hub behind it.
Here you're supposed to be able to remove the long spacer, put the bolt back in and tighten it again to jack the rotor off it's seat. But there is way too much rust for that, and all you'll do is mushroom the bolt and create problems. Just take the bolt out and move on because there is another way, and it involves a hammer.
My handy 2x4 scrap allows me to whack the bejeebus out of the rotor without damaging it. I spin the rotor every couple of whacks to distribute the love. It took quite a few blows to break the rusty bond loose in this case.
Success! You can see where the reluctant rust resides.
The new rotors came boxed, bagged and coated with a gloppy perservative to keep them from rusting.
A liitle WD-40 and a few paper towels takes care of the preservative. But there is no way to get all of the goo out from between the rotor vents, so we expect the brakes to smoke and stink a little over the first few miles until it burns off.
I was curious. 30.5 pounds for a rotor alone was more than expected.
The rotor slips on easily, as its pristine center hole isn't corroded. I install two lug nuts to hold it firm against the hub while the job goes on.
The rotor bolt and its spacer go back on first, but I still think they're useless. But the system expects their mass to be there, so I'm reluctant to simply leave them off. Next, the caliper's zip ties are cut, then the caliper and brake lines are carfully repositioned and the caliper's two large mounting bolts are re-installed...
...and then torqued. Our sources at Nissan told us that 98 lb-ft is the magic number.
After that, the three bracket mounting bolts are re-installed and the ABS wire is slipped back into its slot.
And that's pretty much it for the rotor installation. It's time to put the new pads in. Head back to part 1 to see how it all tuns out.
Dan Edmunds, Director of Vehicle Testing @ 10,001 miles