G.T. Fieros

Greater Toronto Fieros
It is currently Sat Dec 04, 2021 3:37 am

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 9 posts ] 
Author Message
PostPosted: Wed Apr 29, 2015 7:35 pm 
Offline
Single again

Joined: Sun Nov 10, 2013 11:26 am
Posts: 292
Location: Kitchener, Ontario, Canada
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.

Image

Image

Note the pushrod length, this is important.
Image

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.
Image

Here is what it looks like unstaked. Do this on all the area's needing it.
Image

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.
Image

Disassembled, this is how it looks.
Image

Image

In this photo, you'll need to remove this lock clip.
Image

Exploded view.
Image

Look way down and you'll see a circlip. Remove this.
Image

Pull out the pushrod like shown.
Image

This is what you need.
Image

Now, cut the bracket off the Fiero booster. We'll reuse this on the new booster.
Image

This is the bigger 11" booster.
Image

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.
Image

Circlip, pushrod and seal.
Image

Insert pushrod into bore of new booster.
Image

Circlip sitting on top, ready to be installed.
Image

Circlip properly seated.
Image

Retainer, spring and seal goes on.
Image

At the top, you can seal the simple lock ring.
Image

Image

Image

Turn the booster around and install the plastic guide.
Image

Next the spring retainer goes on.
Image

Now the spring.
Image

The front of the booster now gets installed. Compress the spring, and rotate slightly to lock in position.
Image

The studs are too long in my opinion. Cut them to aid in the installation.
Image

The stock Fiero plastic sleeve, on the right, is reused.
Image

Use new nuts with the Nylock insert.
Image

Bolt the Fiero bracket that you cut off earlier. I painted mine to match.
Image

You will have to clearance for the bigger booster. Several judicious blows of a hammer in the offending area take care of this.
Image

Add some paint.
Image

Install the newly modified 11" booster.
Image

Reattach the master cylinder and enjoy! See, easy.


Top
 Profile  
 
PostPosted: Fri May 01, 2015 11:05 pm 
Offline
Newbie

Joined: Mon Mar 23, 2015 11:26 pm
Posts: 19
Location: Innisfil
Wow, nice write up and work :D


Top
 Profile  
 
PostPosted: Wed May 06, 2015 2:04 pm 
Offline
Guru

Joined: Fri Jan 18, 2013 12:24 pm
Posts: 727
Location: Just North of the GTA, Ontario
andrew88 wrote:
Wow, nice write up and work :D



ditto & thanks! 8-)


Top
 Profile  
 
PostPosted: Thu May 07, 2015 5:43 am 
Offline
Single again

Joined: Sun Nov 10, 2013 11:26 am
Posts: 292
Location: Kitchener, Ontario, Canada
If someone wants to do this mod, I have two spare push rods and brackets if needed. Free, come and get 'em. But you'll need to get a new circlip.


Top
 Profile  
 
PostPosted: Fri May 08, 2015 3:03 pm 
Offline
Guru

Joined: Fri Jan 18, 2013 12:24 pm
Posts: 727
Location: Just North of the GTA, Ontario
the one question I've always had & always got different answers is

can you either upgrade to the s10 master cylinder or
do the bigger booster upgrade...
or both?... is it redundant to do both?

ok just to do one? if so which one?

hmmm...


Top
 Profile  
 
PostPosted: Fri May 08, 2015 10:37 pm 
Offline
Single again

Joined: Sun Nov 10, 2013 11:26 am
Posts: 292
Location: Kitchener, Ontario, Canada
OHNIKO wrote:
the one question I've always had & always got different answers is

can you either upgrade to the s10 master cylinder or
do the bigger booster upgrade...
or both?... is it redundant to do both?

ok just to do one? if so which one?

hmmm...



If you have stock Fiero calipers, keep the stock Fiero master and install the bigger booster.

If you have "slightly" bigger calipers (Grand Am, etc), stick with the OE Fiero master. However, if using S10 calipers, then the S10 master would be a suitable choice.

The plungers in the S10/Blazer M/C are larger than the stock Fiero units. This means they are going to move more fluid with the same pedal travel vs. the smaller plungers in the Fiero M/C. However, because they are larger, this means less pressure will be exerted on the brake fluid vs. the smaller plungers in the stock Fiero M/C with the same pedal effort. This of course assuming you are using the same diameter of the caliper pistons in the comparison. This is simple hydraulic theory.

Think of it as pounds per square inch. If you have a 1 sq/in piston with 10 lbs of pressure pushing it, you have 10 lbs per square inch. If it's a 2 sq/in piston with 10 lbs pushing it, you now have 5lbs per square inch. Brakes don't work by amout of fluid but more on the clamping pressure applied. So with the larger M/C you have less travel but it requires more pressure to achieve the same clamping pressure at the brake pads than if you had the Fiero M/C.


Top
 Profile  
 
PostPosted: Sun May 31, 2015 2:58 pm 
Offline
Guru

Joined: Fri Jan 18, 2013 12:24 pm
Posts: 727
Location: Just North of the GTA, Ontario
1995 Suburban booster

where best place to get these?
scrap yard ones ok I gather if they're in ok condition?


Top
 Profile  
 
PostPosted: Wed Jun 24, 2015 5:04 am 
Offline
Single again

Joined: Sun Nov 10, 2013 11:26 am
Posts: 292
Location: Kitchener, Ontario, Canada
OHNIKO wrote:
1995 Suburban booster

where best place to get these?
scrap yard ones ok I gather if they're in ok condition?



The S10 brake booster should be cheaper as they're more common. Although I had a couple of 11" GM booster's in the garage, I used the Suburban one. It was the cleanest of the bunch. The thing with the S10, Suburban, etc is that they come with studs on the back side already in place. While you could essentially use any 11" GM booster, it's these studs (S10, etc) that make mounting of the Fiero bracket easy. I would've drilled and bolted the bracket on had these studs not been there. Too many people are scared of this and thus decline this easy mod.

New booster is the way to go and they're only around $100. You'll have to shop around as I get my parts at cost.
Salvage yard units are okay but try find the nicest one though.


Top
 Profile  
 
PostPosted: Tue Jun 30, 2015 4:08 pm 
Offline
Guru

Joined: Fri Jan 18, 2013 12:24 pm
Posts: 727
Location: Just North of the GTA, Ontario
so you can get them at cost? I need 2 ;)


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 9 posts ] 

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Group