Upgrade - 87 Fiero GT to '91 Beretta/Grand Am Hardware By Randy T. Agee,
My wife (Nancy) drives a '87 GT automatic; I drive a '88 Formula. The brakes
were not too swift on the GT, and the car had a small right front caliper seal
leak so it was due for a brake job. The best way to describe the brakes was
I made the decision several weeks ago to do the Beretta/Grand Am front brake
upgrade. At the time I decided not to do the rear brakes since in Virginia we
are required by our state inspection laws to have an emergency brake. A price
check also showed the Beretta parts were less than half the cost of Fiero parts
I did what research I could. The most comprehensive info came from the Space
Coast Fiero Web Site (www.castlegate.net/personals/daveheld/index.htm). Still,
much of what I found was general info and did not contain any specific data.
Being a visual learner, I wanted pictures, but I couldn't find any.
So, I decided to proceed, learn what I could in the process, and document the
whole thing with lots of pictures.
The 1991 Beretta/Grand Am rotors are the same diameter as the front rotors on
the '87 GT (smaller than '88's). The major difference is they are vented,
consequently thicker and obviously less prone to heating, warping, and fading.
New rotors from Autozone were only $13.99 each. Hard to believe, isn't it?
The aluminum calipers are those used on a '91 Beretta and Grand Am. Physically,
they look a lot like the Fiero front caliper. But, the distance between the
piston side and the outer pad side is wider (has to be for the increased rotor
width). The piston in the Beretta caliper is about 5mm larger in diameter. It
also appears to be deeper. AutoZone had remanufactured calipers for $12.99 each,
plus a $20 core charge. With a wink and a smile, they accepted my old Fiero
calipers for the cores.
I bought standard semi-metallic Beretta pads (Albany brand) at $13.99 for a
two-wheel set. AutoZone has carbonmetalic available for about $26, but I passed.
I took two old Fiero front rotors, pulled the bearings and knocked out the wheel
studs. I dropped these off, along with a Beretta rotor, at our local machine
shop with instructions to cut off the Fiero rotor so the remaining hub would fit
inside the Beretta rotor. The machinist did an excellent job. He took $50 from
my wallet as I walked out the door. This is one part I was "fuzzy" on
in the job descriptions I read. Originally I "thought" I could cut the
Fiero rotor down myself. No way. I think if I have another set cut in the
future, I will have the machinist also remove the "collar" (see
If you have an air chisel, use it with a blunt pointed tool to remove and set
the wheel studs - it works great! If not, I guess a hammer and big punch will do
The new front set-up moves each wheel out 9mm. That is the thickness of the
Beretta rotor at the hub. I installed new wheel studs that measure 54mm in
length. The originals were 42mm. These were a buck each at Advance Auto
(AutoZone did not stock them). Stock studs would probably work OK since the
rears on the Fiero are also 42mm long and have a similar rotor placed over the
stock rear hub, but I don't like to take chances.
I decided to spray the modified Fiero front hubs with high temp engine enamel
before I assembled the parts. I smeared a thin coat of anti-seize on the inside
of the Beretta rotor that goes over the Fiero hub as well. I have some fears of
time and rust making a semi-permanent bond between the two. Hopefully this will
slow that process. Care must be exercised with any release agent used - we don't
want to contaminate the brake pads!
I also purchased a new glide pin set for the Beretta rotors. You could reuse the
Fiero pins (bolts). But, the heads are larger on the Fiero pins and do not fit
well on the front (work OK on the back). AutoZone had them for $3.95 a set.
Lightly lube the bolts before you put them into the slides with some brake parts
grease. Do NOT lube the outside of the slider tube that fits inside into the
As a footnote, I did buy a NEW master cylinder for a 1994 full size Blazer
(about $40 - no core required). But, after listening to Ray Paulk's experiences
with one on a Formula and puzzling over the volume of the Beretta caliper
cylinder I decided to try the Fiero master cylinder first. The Fiero MC worked
and can be used, but pedal travel is increased with the Beretta brakes. With the
Blazer MC the pedal travel is less, but more physical effort is required. Of the
two, I prefer the Blazer master cylinder.
You must file or grind some metal off of the caliper mounting bracket. If you
don't, it pushes against the inside of the rotor. I took mine off to do this and
used a small hand grinder. The original thickness at the mounting points was
21mm, I cut them down to 18mm. I guess you could accomplish the same thing by
placing case hardened washers between the knuckle and bracket. A few drops of
Locktite 202 here and on the ends of the glide pin bolts are necessary. Don't
forget to clean the threads with spray brake parts cleaner first.
The stock Fiero brake hoses work fine, but you will need to open the clamp
around the center of the hose enough to slide/turn it a bit. The hose will need
to be twisted 90 degrees to fit the new caliper. Don't forget to clean the bolt
that attaches the hose to the caliper with spray brake parts cleaner and to use
new copper washers. The larger diameter washer goes on the outside, the smaller
on the inside.
The splash shield will rub the Beretta rotor. It will need to be bent back a
little to provide clearance. I had to cut a small piece off of the top end of
the shield to clear the Beretta caliper when I bent it back.
I replaced both inner and outer wheel bearings. The outer Fiero bearing looks
like something out of a wheelbarrow. Next time you rocket down the road at 100
mph, remember that cheesy little bearing. They should be serviced every time you
change oil anyway. You will also need a new inner grease seal. The right tools
make this a simple job and it is nice to have a seal remover, driver and grease
packing tool. I also used Mobil 1 synthetic high temperature grease in the front
bearings as a little extra insurance. If you don't have the right tools, buy an
extra seal or two. It is easy to distort them when using a block of wood and a
hammer - so the spares may come in handy.
I threw for a Mighty-Vac one man brake bleeder kit ($25.00) to make the job a
little easier and cleaner. It is a welcome accessory tool. I picked up two large
bottles of Valvoline DOT-4 Synthetic brake fluid and completely flushed out the
old fluid in the system. I did this BEFORE I put the new calipers on so I would
not get old dirty fluid in them. The old fluid looked like dirty motor oil.
DOT-4 is a suitable replacement for older DOT-3 (which came in the Fiero).
I was very impressed when I first test drove the car. The results were
impressive, but the front brakes had too much pinch. I was afraid that could get
Nancy into trouble on a wet road. So, I decided to go ahead and toss the
emergency brake and put the Beretta stuff on the rear too. The backs are a
direct bolt-on. No modifications are needed other than twisting the brake hose
and storing the handbrake cables.
With new brakes on all four corners, a new master cylinder, and fresh fluid the
little red car will stop on a dime. There is only one word to describe the
changes experienced. ****AWESOME!!!**** It was worth every penny spent and I
highly recommend it for any 84-87 Fiero. In fact, right now the brakes feel
better than my '88! The overall cost is actually LESS than fixing and replacing
the same parts with stock Fiero and it is not hard to do.
The lack of an emergency brake does bother me and I will need to "injun-ear"
something that will work. The line-locks in Jegs and Summit catalogs appear to
require a constant 12 volts to keep the brakes locked. That won't work. But, JC
Whitney has a Jamar in-line brake lock that looks promising (85BF6592Y for
$22.95). I "think" I can mount this device in the rear brake line and
use the original brake cable from the emergency brake through a lever to actuate
the valve. This way, I could step on the foot brake, pull the lever, and lock
the rear calipers. There are some minor problems to work out on this approach,
but I believe I can make this device work safely. If you have any experience in
"alternative" devices for emergency brakes, I would really like to
hear from you.
March 2001 Update
We (the Fiero Ranch) no longer do or recommend rear brake conversions. We
have found that using the original Fiero Rear brakes with rebuilt calipers, new
pads and cleaned, true rotors will give overall braking performance equal to the
Beretta rear upgrade. We also strongly advise using new braided SS brake
lines... or at least new rubber lines. Since the majority of braking effort is
on the front, the front only Beretta upgrade creates a tremendous improvement.
This also allows you to keep a legal E-brake on the rear!
When doing the front only upgrade you may retain your original master cylinder.
You will have approximately 1/2" more pedal travel and slightly less pedal
effort. You may also use the full size Blazer MC mentioned in this article with
approximately 1/2" less pedal travel and slightly more pedal effort, or you
may use a 92-93 S10/S15 Master cylinder for near OEM pedal travel and effort.
5046 Sandy Valley Rd.
Mechanicsville, VA 23111
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