Note:
The parts referenced in this procedure are from a 1979 to 1984 Datsun/Nissan
280ZX (not a 280Z). Thanks to Richard Jurabek for bringing this to my
attention. When I was scouring the wrecking yard for likely candidates for
this swap I did not pay attention to what I was taking it from.
Pics are from Left to right: Complete assembly in car, 280Z disc and caliper
mounted on modified bug hub, Bus/Buggy type single cylinder master cylinder.
In the search for better braking, we tried a number of things. We did
the brake bias swap with the stock VW stuff, wider brakes, bigger brakes,
different master cylinders and a number of other things. Nothing holds a
candle to having rear disc brakes. I looked in to using some of the
aftermarket bolt on stuff but found that I was not willing to put out five
hundred dollars or more for more stopping power.
The solution I landed on was
the use of 280Z rear disc brakes. I had the rear end out of a 280Z that I
was stealing the axles out of for my next Baja and found that the discs were the
slip on type. I also had the rear hub assembly out of a type 4 and found
that it was two piece. The hub came loose from the drum. Then the
idea hit me. Why not just use the center out of a VW drum, convert it to
studs, and slip the disc over it.
Pics are from left to right: 280Z disc still on 280Z spindle, Type 4 two
piece drum, Type one drum marked for cutting, Type 4 Hub center on custom lathe
spindle, Type 4 hub center on lathe, and again.
After examining the parts I had I found that
I had to turn down the outer diameter of the hub. A full drum could also
be used and turned down the same amount. This mod will only work with the
four bolt drum. I turned down the hub so it would fit inside the
disc. The center of the disc had to be enlarged to fit around the center
of the hub. Once the pieces fit together, I installed them on the back of
the bug.
The next step consisted of creating a disc brake caliper mount on the
rear of the trailing arm. The 280Z brakes are designed to be straight off
the back of the car. After placing the caliper in place I attached an air
hose to the brake line and pressurized the caliper. I made sure that I
used new pads and that the caliper was as centered as I could get it. I
then cut a piece of 3/8" plate so it would fit around part of the caliper
and match up to the mounting holes and would hit the end of the trailing
arm. Since I was using my own 2x3 rear arms, the mounting point was a
flat, square surface.
The easiest way to get the right shape is to cut out a
piece of cardboard and trim it until it is the right shape. Then transfer
the shape of the cardboard to the metal and cut it out. I finished it up
with some grinding, drilled and tapped the mounting holes for the bolts that
hold the caliper on and welded it in place.
The brake lines were the same as
were on my drum brakes so the installation of the brake lines was very
easy. A quick bleed and I was ready for the test.
The rear 280Z brakes
also come with the e-brake system on the calipers so I could hook up the e-brake
if I were to make this street legal.
The braking was a huge improvement.
I find that I have much better and consistent braking control regardless of whether
the brakes are wet or dry. My turning brakes work with much less effort
and I can lock them up whenever I want. The most satisfying result is that
I can better control WHEN the brakes lock.
I think I have about $25.00 in
parts and a couple hours worth of time.
Well worth it!!