What do I need to do a Z32 Brake Conversion?

by ryandriftingfat on May 28, 2010

For an S-chassis, a Z32 brake upgrade is one of the best upgrades which can be done to boost stopping power on these old hoopties.

Stock brake suck-fest.

A stock, US market S13 or S14 comes with a single piston caliper. The much heavier Z32 300ZX, in all it’s forms, feature 4-piston opposable calipers. Upgrading from stock brakes to Z32 brakes up front is very easy, and very common. There isn’t a form of driving that won’t benefit from increased stopping power, so get to work.

For S13 or S14 Front:

  • Z32 Calipers (26mm/30mm Aluminum or 30mm Iron)
  • Z32 Rotors (OEM or Aftermarket)
  • Z32 Brake Pads (OEM or Aftermarket)
  • S13/S14 -> Z32 Conversion Brake Lines
  • Z32 Caliper Hardware Kit (If buying new/rebuilt calipers)
  • Z32 Caliper Shim Kit (Optional, pad shims reduce brake noise)
  • Z32 Brake Master Cylinder (Optional, stronger than 240SX Master Cylinder)

Instructions (brake installation):

If you are thinking about getting the Z32 master cylinder, new or used, this would be the optimal time to do it, bleeding the brake system isn’t fun to do over and over. I did a complete swap, new front & rear rotors, pads, stainless lines, z32 master cylinder, and speed bleeders.

Jack up the front end and remove the wheel. Attach a tube of some sort to the bleeder screw (I used vacuum tube) and have it empty into a bottle. Open the bleeder screw and pump the brake pedal until you see nothing comes out of the lines. Tighten it back and proceed to the next caliper.

Once the brake hydraulic system is empty, you can remove the 2-12mm bolts holding the caliper onto the brake pad bracket. Next, remove the little C-clip on the strut body to release the rubber brake line and push the caliper aside. Break out the 10mm wrench (line wrench is best here) and go to work unbolting the rubber brake line from the hard line. You will be loosening the hard side of the line, which is above the bracket on the body. Be careful with the line nut, they can be on pretty tight and you don’t want to strip it. After you have it loosened, remove the C-clip from that bracket and pull the rubber line out. Toss the line and caliper aside. Now for the brake pad bracket, there are two bolts holding it to the spindle. I believe they are 17mm, break those loose and set the bracket aside with the brake pads. Now you should be down to bare rotor. If it gives you any crap when you try to take it off, get your trusty rubber hammer and start with some light bashing. It will come loose, then just put it aside.

If you are doing a S13 5-lug swap, you can remove the dust shield when you change out the hub. It comes off pretty easily with a rubber hammer. If you want to keep yours, you’ll need to cut the dust shield so that the larger rotor and caliper can still spin freely. I used a dremel, but it’s a long and tedious process with that crap and I decided to lose the dust shield completely.

After the shield is modified or removed, put the new rotor on. Spin it a few times to make sure it’s not scraping anything, then put the caliper into place and put the two spindle bolts back on. At this point, I would suggest that you already have the new brake line installed and lightly tightened down on the caliper and hard line. Lightly tightening them down puts the line in their correct place, but still allows you to move it around to suit your setup. Lightly tighten the spindle bolts down, and spin it again. So long as nothing scrapes, torque both down to 60 ft-lbs. Now mount the line in the C clip on the strut body, mount the C clip on the body and tighten the stainless line to the hard line. Then do the same on the other side.

Once everything is bolted down tightly and spins freely, bleed the brakes. Bleed the brakes in sequence; RR, LR, RF, LF (speed bleeders are a god send if you don’t have an assistant). Down a bottle of your favorite brew while admiring your work and call it a day.

Instructions (master cylinder, S13):
Someone was using their head over at Nissan when they were thinking of parts interchangeability. Z32 master cylinders have the exact same bolt and line locations as the S13. S14 owners, not so lucky. For NON-ABS S13, there are 3 lines off the master cylinder, use your 10mm line wrench on them and make sure not to round them off. Break them loose and then there are two more bolts (I believe 10mm) holding the M/C onto the brake booster. Loosen those, and the old M/C will come off, installation is the reverse of removal. ABS S13’s only have two lines off the M/C, which can be good or bad, and I will explain later. The center line will have a cap on it.

Instructions (master cylinder, S14):
S14 owners have two options if the stock M/C isn’t to their liking with Z32 brakes. A Z32 M/C, which requires bending the stock hard lines to fit the Z32 line configuration. Second option is get the M/C off of an S14 K’s clip. S14 Silvia K’s in Japan use front brakes which are very similar to Z32 front brakes. The master cylinder is bigger, and the same M/C will fit both LHD and RHD platforms. The only problem with the latter is that you can’t just go to AutoZone and pick up a replacement M/C. There are enough clips laying around though, you should be able to source them fairly easily. Otherwise, installation is the same as S13.

S-Chassis M/C Options, the details:
For Z32 master cylinders, Nissan used 3 different M/C sizes and at least 2 manufacturers. The general consensus is that you want either the 16/16″ or 17/16″ M/C. Z32’s made before 8/91 generally carry the 17/16″ M/C. The problem with any Z32 M/C though, it usually won’t have a flair fitting for the center hard line, Z32’s all have ABS and use just two hard lines. This is fine for S-chassis cars with ABS, not fine for Non-ABS.

Here are your options: Find an M/C and check to see if the middle line has a flair fitting. If it does have it, no problem. If it doesn’t, you need to either source flair fittings (check the community) or cut up your old M/C with a rotary tool to extract the fitting.

I kind of took the easy way out with this step, but not on purpose; I was going to destroy my old M/C. I went to Napa and bought a Z32 M/C for a car made before 8/91. The reason I bought from them was that the salesman was the only one from all of the parts houses who assured me that it was a 17/16″ plunger. I bought a brand new unit for around $140. When it arrived, all three holes had green twist off caps, and to my delight, the center hole had a flair fitting in it already. I didn’t realize until months later though that my M/C may not actually be a 17/16″ plunger. Supposedly the 15/16″ and 17/16″ both have their measurement in the casting, and the 16/16″ did not – mine has no measurement in the casting. Honestly, if mine was 16/16″, fine, it felt great. Going from stock S13 to 16/16″ Z32 was night and day. The part number for the M/C from Napa is 47-39777.

Brake Master Cylinder Update 7/23/11;
The part  number has changed but the product looks to be the same. I just picked up the master cylinder pictured below again from Napa. It has a different part number from the one I had on my first S13. The new part number is MC39777, which appears to be a 16/16″ 1990 Z32 BMC. More info in my blog posting here.

Z32 Brake Master Cylinder Update 12/23/11;
It looks like Amazon is now carrying the master cylinder you’ll need to match the Z32 brakes, here: 240SX Brake Master Cylinder