When I purchased the car back in January, it had been sitting for almost 17 years. I ordered new AC Delco rotors/pads, bearings, hoses, the best PepBoy's calipers offered with excellent reviews. Once I started the job, I discovered all the hose fittings were fused, decided to replace the entire line with the SS kit from FS running quality DOT3.

Once installed, I followed the factory manual procedure to bleed. Brakes have always been spongy since, bled twice to be certain I did the procedure correct.
I moved on to my Honda project, now back to Fiero driving it daily until Honda is done, will then start the complete Fiero project.

The issue I have is with these spongy brakes, something I have planned to address, the cheap AC Delco parts were meant only for a temp/safe fix as I wasn't driving the Fiero often. Twice I've had to stomp on the brakes, which produced a grinding sound from the front right. The first time it went away, today it's hanging around a bit longer. Like the pad has bedded in, I will pull the wheel tonight and inspect further/

I see it has enough pad material albeit it's unusually worn for less than 2K. My thoughts are the master also needs replacing, though the fluid level is maintaining proper level. While I am at it, go for the new Summit S-10 booster and Rodney's pending new kit: Rodney's S-10 adapter with new SS brake hoses since I will be mildly building up my Iron Duke. I have seen partial threads mentioning the Grand AM upgrade, would be nice if a sticky existed to guide user's on the correct parts and procedures. I am aware of Ogre's Brake Upgrade article.

So recap, my meant to only be temp brake job, has another underlying issue which I suspect is the MC.
Considering upgrade to S-10 booster/SS lines, worthwhile upgrade to support my engine build?
Which caliper/rotor modifications are suggested with proven results?

Disclaimer: So I am clear, I am restoring the car completely, resto-mod, I am not "throwing" parts at it to fix issues, logic says if it's been sitting/neglected, it needs to be replaced/rebuilt. I want to efficiently use my money during the restoration to safely correct issues as encountered, secondly, enhance performance to compliment pending engine modification, last, insure all systems have been properly reconditioned/repaired.

Or, am I better off with a good stock/reconditioned system and good quality hardware ie; rotors/pads like the EBC Green?

If you can detect any heat on that wheel after driving for a while, I would replace the brake line hose, even if you already did it. Any malfunction of the master cylinder should affect more than one caliper.

[This message has been edited by Gall757 (edited 11-11-2014).]

quote Originally posted by Gall757: If you can detect any heat on that wheel after driving for a while, I would replace the brake line hose, even if you already did it. Any malfunction of the master cylinder should affect more than one caliper.

Good point, sometimes you need outside opinion to quiet your own thoughts. This morning, after a hard brake, as I said, the caliper is making a grinding noise at low speed, goes away around 40, disappears, comes back every so often. Same as before a few weekends back, caused by a very hard stop due to traffic.

The common denominator with the issue it's brought on by a hard stop. Luckily I think that line was bought at NAPA, under warranty, but the Amazon purchased line should be as well. Tide me over until I can get the upgraded components in place.

[This message has been edited by mckaymotoworks (edited 11-11-2014).]

Could also be the slides. Did you check that they slide easy and dont bind? If the caliper doesnt slide freely the piston may have to travel more and cause a spongy feel. Meanwhile the outer pad tends to rub all the time and wear out prematurely.

Check all of the hardware like was noted above. The calipers should slide on both pins easily by hand. Check for pinched or twisted hard lines. Check the outer AND inner edges of the rotors for rust that rubs against the caliper or dust shield. Make sure the dust shield isn't rubbing anything. Remove caliper and inspect the bearings. Do the rotors spin freely? Any side to side play? Double check the nut to ensure they're not over or under tightened.

How do the pads look? Worn evenly on both pads / across each pad? If one pad is thinner or you have one or both worn at an angle you need to clean and/or replace (and grease) the pins. A sticking piston can also cause fast wear, usually even across one pad.

If you have a dragging pad, you'll get a lot of heat and smell. The heat will cause sponginess (brake fade) as it progresses, then go away when cooled off. The brakes may also feel touchy or grabby.

Hope this helps.

------------------
1986 SE Aero coupe.

3.4 DOHC swap is complete and running, now just have to finish the rest of the car...

[This message has been edited by tesmith66 (edited 11-12-2014).]

Just like last time, after it sat for a while, the grinding/rubbing is gone. Must be holding pressure on that side when over forced, or slide sticking as said.
I will check the items above, does sound like the slide could be sticking.

Back to the second part of my question. Is the booster upgrade worthwhile for a car with 112-120hp?
Rock Auto seems to offer some better Centric rotors, will run the EBC Green pads

I have always found the stock brake system to be just fine. As long as it was back to factory specs. I wouldn't bother changing out the booster, or going with "fancy" pads at this point. Just get it working. I would check the slides and check them when the caliper is installed, as I had a slide on an '88 that would bind when caliper bolts was clamped down (different caliper design, but it could happen on 84-87). That was annoying to fix, but a small... thin shim fixed it.

You replaced all the rubber hoses correct? Are you getting good flow from the bleed screw, when you bleed the brakes?

I would double check the bearings, the pads and the dust shield, as these could cause grinding issues. Spongy brakes.... Are you getting any air bubbles when bleeding?

Yes, all new hoses with SS lines. I had good flow as I did the prescribed bleed sequence, until no bubbles.
New bearings in front, SKF I believe, I am anal about non Chinese or crap parts.

Do not mind paying a premium for a good product and warranty. All good suggestions, will check this weekend.
I need the Honda back up so I can start my 4 speed swap and engine work on the Fiero.

As far as fancy pads etc, that's when the engine and suspension work is completed.