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identifying nonfiero brake mods by mad dad matt
Started on: 07-03-2015 12:07 PM
Replies: 17 (291 views)
Last post by: olejoedad on 07-08-2015 07:49 AM
mad dad matt
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Report this Post07-03-2015 12:07 PM Click Here to See the Profile for mad dad mattClick Here to Email mad dad mattSend a Private Message to mad dad mattEdit/Delete MessageReply w/QuoteDirect Link to This Post
OK. I bought an 87 es a while back.(back story of previous owners skill and logic)The kid blew the motor by not adding oil after an oil change,so dad had a tech4 rebuilt and installed.Then the kid did some brake work,place a 12 inch hula dancer on the dash (yes it blocked out the view) then went for a drive.This ended abruptly in the back end of a BMW.Dad was a little upset with kid and sold me the car cheap.
A gallon of fiberglass,some paint,tube stock,and a welder fixed the front end.found a leak in the master cylinder brake line fitting.bled the brakes checked the rotors and pads look new.Front looks stock but the back has no ebrake linkage.The rears do apply when tested on jack stands but if i drop it into reverse on a rock hill it will drag the locked up front tires down the hill.
FINALLY MY QUESTION...
Was this a GP upgrade attempt or maybe some other mod.How to tell if the master was swapped.Any suggestions getting the balance correct.
I have only played with fieros for a few years but i built a 10sec street class chevy before this car rolled off the assembly line.looking for fiero mod details to figure out what they were trying to do so I can finish.Half done is not working well.
Thanks for reading my rambling and any info is appreciated
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Blacktree
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Report this Post07-03-2015 02:59 PM Click Here to See the Profile for BlacktreeClick Here to visit Blacktree's HomePageClick Here to Email BlacktreeSend a Private Message to BlacktreeEdit/Delete MessageReply w/QuoteDirect Link to This Post
The '87 Fiero comes stock with solid rotors on all 4 corners. If any of the rotors on your car are vented, then the brakes have been upgraded. You can usually tell the type of upgrade by the rotor diameter. Some examples:

The Grand Am / Beretta brake upgrade uses 9.75" rotors.
The LeBaron brake upgrade uses 11.25" rotors.
The Corvette brake upgrade uses 12" or 13" rotors.

If all the rotors are solid, then the car most likely has stock brakes, and they just need some repair.
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Patrick
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Report this Post07-03-2015 03:04 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by mad dad matt:

Was this a GP upgrade attempt or maybe some other mod.How to tell if the master was swapped.Any suggestions getting the balance correct.


It would probably help a lot if you perhaps posted some pictures of what you're dealing with. Use PIP to post images here.

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2.5
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Report this Post07-03-2015 03:52 PM Click Here to See the Profile for 2.5Send a Private Message to 2.5Edit/Delete MessageReply w/QuoteDirect Link to This Post
This site has some pics of factory brakes and one upgrade people do/did back in the day.
http://myfiero.oceanmoon.co...-fiero-brake-upgrade

Grand Am brakes
http://www.fiero.nl/forum/Forum2/HTML/122182.html

[This message has been edited by 2.5 (edited 07-03-2015).]

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mad dad matt
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Report this Post07-04-2015 12:50 PM Click Here to See the Profile for mad dad mattClick Here to Email mad dad mattSend a Private Message to mad dad mattEdit/Delete MessageReply w/QuoteDirect Link to This Post
Thanks for the response.I have seen both of the links in the past. The front has the bearing race in the disk so it is stock or the fiero stores over sized disk with the built in race. No milled hub under the disk.I don't know the specs for the fiero stores disk. I just bought 86gt so I need to measure and compare to be sure the 87 fronts are stock.( assuming the gt is stock)From what I have seen oversize front caliper will starve the front so you get rear bias.The mystery is the back has no ebrake setup on the caliper and I forgot to mention the disk is not vented,single disk plate.maybe he added the gp calipers but kept the stock disk? I read one place you need to raise the rear end when you bleed the rears.They made it sound like more than just enough to pull the tires.Never seen that before but worth asking if it is a fiero thing.
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olejoedad
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Report this Post07-04-2015 01:12 PM Click Here to See the Profile for olejoedadClick Here to Email olejoedadSend a Private Message to olejoedadEdit/Delete MessageReply w/QuoteDirect Link to This Post
The rear brakes could just be Fiero front calipers, used to avoid the expense of replacing with rear calipers.
88's use the same piston diameter front and rear.
Pre-88 have different piston diameters front and rear, which could explain your bias problem.
If, indeed, all of the calipers on the car are front calipers, your bias problem could be solved by using an 88 bias valve.

[This message has been edited by olejoedad (edited 07-04-2015).]

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theogre
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Report this Post07-04-2015 01:23 PM Click Here to See the Profile for theogreClick Here to visit theogre's HomePageSend a Private Message to theogreEdit/Delete MessageReply w/QuoteDirect Link to This Post
Add picture as noted above helps you alot here.
Missing e-brake parts could be several problems. Including people using front caliper on rear axle. Pictures will help why w/ that too.

Jacking to bleed is a myth.
Start here, See my Cave, Brake Service
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Blacktree
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Report this Post07-04-2015 02:27 PM Click Here to See the Profile for BlacktreeClick Here to visit Blacktree's HomePageClick Here to Email BlacktreeSend a Private Message to BlacktreeEdit/Delete MessageReply w/QuoteDirect Link to This Post
I'm guessing one of two things happened:

1) The car still has the stock rear calipers. But since the parking brake hardware is gone, the rear calipers are out of adjustment.

2) The rear calipers were replaced with front calipers, which threw off the brake balance.
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theogre
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Report this Post07-04-2015 11:18 PM Click Here to See the Profile for theogreClick Here to visit theogre's HomePageSend a Private Message to theogreEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Blacktree:
I'm guessing one of two things happened:
1) The car still has the stock rear calipers. But since the parking brake hardware is gone, the rear calipers are out of adjustment.
2) The rear calipers were replaced with front calipers, which threw off the brake balance.

1 is very possible. BUT Good rear pistons will self-adjust without parking cables. So when true then need rear calipers and e-park parts and cables for everything to work.
2 if used Fiero front calipers is a minor issue. if used GA front is a very big problem.

Pictures can/will show both.
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mad dad matt
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Report this Post07-05-2015 05:55 PM Click Here to See the Profile for mad dad mattClick Here to Email mad dad mattSend a Private Message to mad dad mattEdit/Delete MessageReply w/QuoteDirect Link to This Post
I pulled apart the drivers front and rear,took pictures as I went with a measuring tape to show scale.The front look smaller but it was the different paint colors he used on the front and rear.So the calipers on the rear are definitely front calipers.Switching to an 88 bias valve or an adjustable valve sounds like my next direction.Do I need to upgrade the master or booster?
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olejoedad
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Report this Post07-05-2015 07:03 PM Click Here to See the Profile for olejoedadClick Here to Email olejoedadSend a Private Message to olejoedadEdit/Delete MessageReply w/QuoteDirect Link to This Post
Drive it for a while, the bias may be just fine.
The 88 bias valve is set up for matching diameter pistons all around.
If your existing master and booster work OK, there is no need to change them due to the calipers.
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mad dad matt
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Report this Post07-05-2015 08:15 PM Click Here to See the Profile for mad dad mattClick Here to Email mad dad mattSend a Private Message to mad dad mattEdit/Delete MessageReply w/QuoteDirect Link to This Post
Thanks to everyone for the help.I have 10,000 miles over the last 17 months so i don't think it will blow out anymore cobwebs.The brakes work and normally stop good but it is that rare occasion on rock,hard rain,or fade from overheating that stop your heart for a second.Sometime you need that extra 20% braking from the rear.
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mad dad matt
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Report this Post07-06-2015 12:18 PM Click Here to See the Profile for mad dad mattClick Here to Email mad dad mattSend a Private Message to mad dad mattEdit/Delete MessageReply w/QuoteDirect Link to This Post
SOOOO... replacing the portioning valve isn't as simple as I thought. Nobody has one.Unless there is another model that is a direct replacement part.Nothing is listed in my parts interchange book. A few people were building them years ago for around $150. The Universal valves I found are simply a variable flow reducer. The opposite of what I need.
So plan B. Upgrade the front brakes to GP.
The larger caliper should help the bias balance.? Parts are under $150. I can machine the old disks myself to keep the hub. Should reduce brake fade. No two people seem to agree on the right combination to do the brake upgrade or the effects.Since this is all fiero specific I am in uncharted waters. I don't want to waste time and money making it worse so I appreciate any input.
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olejoedad
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Report this Post07-06-2015 12:55 PM Click Here to See the Profile for olejoedadClick Here to Email olejoedadSend a Private Message to olejoedadEdit/Delete MessageReply w/QuoteDirect Link to This Post
My 86SE uses the GrandAm front calipers and rotors on all four corners. I am using the 86 bias valve and a master cylinder from an early 90's S-10 Blazer 2WD.

They will put you through the windshield and have good balance and modulation.

Have you checked your existing setup for glazed/heat checked pads and rotors, and bled the system properly?
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mad dad matt
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Report this Post07-06-2015 06:31 PM Click Here to See the Profile for mad dad mattClick Here to Email mad dad mattSend a Private Message to mad dad mattEdit/Delete MessageReply w/QuoteDirect Link to This Post
Just saw I typed GP (grand prix) was trying to type GA (grand am). I may start with the front swap and go from there. I can't tell you how many times I have tore the brakes apart,scuffed,cleaned,reassembled and bled. Always thinking I will find the problem.Never do.
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olejoedad
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Report this Post07-06-2015 07:26 PM Click Here to See the Profile for olejoedadClick Here to Email olejoedadSend a Private Message to olejoedadEdit/Delete MessageReply w/QuoteDirect Link to This Post
Can you text or email me pictures of what is now on the car?
I can PM you contact info.
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mad dad matt
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Report this Post07-08-2015 12:25 AM Click Here to See the Profile for mad dad mattClick Here to Email mad dad mattSend a Private Message to mad dad mattEdit/Delete MessageReply w/QuoteDirect Link to This Post
A few pics should be in you email inbox.
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olejoedad
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Report this Post07-08-2015 07:49 AM Click Here to See the Profile for olejoedadClick Here to Email olejoedadSend a Private Message to olejoedadEdit/Delete MessageReply w/QuoteDirect Link to This Post
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