For those of you that are interested in installing a larger brake booster on your Fiero, this is for you. It's not that difficult to do, really. Follow along if you will.
Note: Some use the 96 S10 booster for this mod. I used a 1995 Suburban booster because I had it. It's an 11" dual diaphragm design. It also has studs that make in easy to bolt the Fiero booster bracket to.
Remove the old booster from the car. You can actually move the brake master out of the way, leaving the brake lines intact. You'll have to remove the little screw that holds the proportioning valve in place. Once this is done, unhook the booster pushrod from the brake pedal, remove the four bolts from the booster, and place it on the bench. We need some parts from the stock Fiero booster.
Note the pushrod length, this is important.
This is the bajonet fitting. You'll see there are a few places that are staked. These need to be unstaked. Using a screw driver makes this easy.
Here is what it looks like unstaked. Do this on all the area's needing it.
Place the booster in a vice as shown. We're going to rotate the housing. It does have a spring in there and it will fly apart. Prepare yourself and get a helper to hold down the top of the booster while you rotate.
Disassembled, this is how it looks.
In this photo, you'll need to remove this lock clip.
Exploded view.
Look way down and you'll see a circlip. Remove this.
Pull out the pushrod like shown.
This is what you need.
Now, cut the bracket off the Fiero booster. We'll reuse this on the new booster.
This is the bigger 11" booster.
Like you did with the Fiero booster, take the new one apart the same way. You can see the different length pushrods between the two. The Fiero pushrod is the longer of the two. This is what we'll be using in the bigger booster.
Circlip, pushrod and seal.
Insert pushrod into bore of new booster.
Circlip sitting on top, ready to be installed.
Circlip properly seated.
Retainer, spring and seal goes on.
At the top, you can seal the simple lock ring.
Turn the booster around and install the plastic guide.
Next the spring retainer goes on.
Now the spring.
The front of the booster now gets installed. Compress the spring, and rotate slightly to lock in position.
The studs are too long in my opinion. Cut them to aid in the installation.
The stock Fiero plastic sleeve, on the right, is reused.
Use new nuts with the Nylock insert.
Bolt the Fiero bracket that you cut off earlier. I painted mine to match.
You will have to clearance for the bigger booster. Several judicious blows of a hammer in the offending area take care of this.
Add some paint.
Install the newly modified 11" booster.
Reattach the master cylinder and enjoy! See, easy.
