Just got my Formula out for the first time in a couple of months. It needed a new battery, so I ran out and got it replaced. On that errand, I wasn't particularly impressed with my brakes, which have Thermoquiet pads. When I got home, I took a little detour, and did some hard braking from 70ish down to 20ish. Made a u-turn, and repeated. After about the 5th hard stop, the brakes really woke up. The first 4 stops... it was all I could do to get the tires to chirp, and I couldn't lock them. Somewhere around stop #5... I had more than enough to lock the wheels easily. Did I finally burn off a glazing? Or do these pads need some heat to work properly?
Could be normal for TQ, oil/grease contamination cause glazing, or could be problems w/ calipers etc. Like rear gets too much clearance.
Any pads change performance as temp goes up. Normal pads fade at high temp.
Did you turn old rotors? If not then new pads take longer to "bed" on old rotors.
Did you use new rotors? If yes, Did you Clean the new rotors? New Rotors have a coat of "oil" to prevent rust and need to clean that off. I clean them w/ Dawn dish soap in the kitchen. Oil is Veg base...
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
Originally posted by Gall757: Spider webs on the rotors? Moisture in the pads? Depending on weather, brake rotors can have rust on them in 3 days.
TQ and most others doesn't care about moisture. Normal Rusting should not cause problems. He drove enough before testing to scrub rust off.
Spider webs on the rotors? If you mean stress cracks, the rotors are in big trouble. Get new rotors, likely pads too, and fix dragging pads. Slotted/drilled rotors are famous for stress problems even w/o dragging pads.
I'm pretty sure that hydraulically, my system is in good working order. When I installed the pads, I did a lot of other stuff, too. - New rotors (that were cleaned) - New roll pins (some of the old ones were bent) - Cleaned & re-greased the sliders - Repaired the e-brake*
* There is a thrust washer on the back of each of the rear calipers that must be there for the e-brake system to work and adjust properly. One of mine was missing. After replacing it (and properly adjusting my cable), I had a working e-brake for the first time ever. It will even hold on a hill, now. So I'm confident that there's no excess clearance on the rear pads.
That was back in Apr, 2010, about 8000 miles ago, so I'm pretty sure that they're about as bedded as they're going to get.
Re: rotor cleaning.... I ALWAYS clean the rotors before a brake job, whether they're new, or they've been turned. I've been bitten by not doing that in the past. New rotors, as mentioned, will have something on them to prevent rust. And turned rotors will typically have greasy fingerprints. I'm almost anal about cleaning. That's one reason I don't let shops do brake jobs for me. That, and the fact that I'm the only person who will use a torque wrench on my caliper bolts and lug nuts.
When I do a brake job, I always either turn the rotors, or I replace them.
Rust on rotors.... I'm SURE that they had rust, but that goes away pretty quickly. The first 2 or 3 applications of the brake are usually quite noisy. Then they quiet down.
The moisture in the pads sounds plausible. The car sits outside in the driveway, and this was the first time it had been driven in a couple of months. The errand didn't do too much to tax the brakes until I did the hard stops. So it seems possible for the moisture to still be there after a short drive.
About 6 months after doing the above brake job, I had to do a panic stop (idiot pulled a u-turn in front of me from the lane to my right). The fronts locked, the rears didn't, and that was with all the force I could muster on the pedal. In this most recent "brake test", the brakes started out worse than they were for the panic stop, but they improved to better than they were for the panic stop.
My question was more of the "Do Thermoquiet pads behave like this normally, or is this something else?" variety. I was kinda surprised that the braking improved that much, hence my curiosity.
After about the 5th hard stop, the brakes really woke up. The first 4 stops... it was all I could do to get the tires to chirp, and I couldn't lock them. Somewhere around stop #5... I had more than enough to lock the wheels easily. Did I finally burn off a glazing? Or do these pads need some heat to work properly?
My question to you would be... What were the brakes like the next day?
Originally posted by Patrick: My question to you would be... What were the brakes like the next day?
I haven't driven it since. It has a problem with the cooling fan, so I'm not comfortable driving it to work (in stop and go traffic). I may try it tonight.
Originally posted by Formula Owner: ... About 6 months after doing the above brake job, I had to do a panic stop ... The fronts locked, the rears didn't, and that was with all the force I could muster on the pedal. ...
Originally posted by Formula Owner: I had to do a panic stop (idiot pulled a u-turn in front of me from the lane to my right). The fronts locked, the rears didn't, and that was with all the force I could muster on the pedal.
This is Normal operation for most cars w/o ABS. Locking rear cause car to spin very easy and often.
Prop valve's job is to regulate max pressure to rear brakes. Most OE prop valve are set so prevent rear lockup on many dry surfaces and damp to wet pavement. See my Cave, Combination Valve
Where these pads new? I always thought you had to gently break in pads, such as multiple 30mph near stops, avoid getting them hot for a while to "bed them in".
Where these pads new? I always thought you had to gently break in pads, such as multiple 30mph near stops, avoid getting them hot for a while to "bed them in".
No, they're not new. About 5 yrs old, with about 8000 miles on them. I took it easy on them for a while when they were new.
Maybe its not the brakes. Maybe repeated braking caused the tires to heat up and become more sticky?
That's not what's happening. If the tires had started out cold and slippery, then the first hard braking test would have resulted in locked wheels. I could tell that the amount of force needed on the brake pedal was getting lower. On the last 2 "tests', I had to modulate the brakes to keep them from locking. I.e. I had to apply less than full force to the brake pedal. The brakes were definitely developing better braking.
My question to you would be... What were the brakes like the next day?
I finally have an answer to this. I got the chance to take it out again today, 8 days after the last drive, and the brakes were great from the beginning. No heating required. So this means that it was a one time thing... Something like moisture in the pads, or glazed rotors. Either way, my brakes are GREAT now! In fact, I wish that it took a little MORE pedal force to get to lockup. They're just slightly more sensitive than what I'd consider perfect. I'm convinced that if everyone's stock brakes worked as well as mine, there wouldn't be a market for brake upgrades, unless it was for larger rotors to go with larger wheels.
Edit: After thinking about this, I retract some of that. I can see upgrading solid rotors to vented to improve fading.
[This message has been edited by Formula Owner (edited 02-15-2015).]
Need to post an update. My brakes will no longer lock my wheels. I recently tried a repeat of my "brake stress test" above, where I apply the brakes hard several times. I go the brakes hot enough to start smelling hot, but at no point could I lock the brakes.
Troubleshooting to follow. My first suspicion is the sliders. I suspect that the grease on the sliders has dried up, and I'm only getting braking from one side of the caliper. When I get a chance, I'm going to re-grease the sliders.
BTW, how long does it take for a thread to get archived?
I'm not sure that threads even get archived any more, since disk space has gotten so inexpensive.
With that said... I have stopped buying Thermoquiet pads. The last ones I had dusted like hell. (My G6 is/was a DD, so I've been through several sets.) Same with the ones that were on my Silverado. Think I used Delcos the last time on the G6. Not sure about the Silverado, but it doesn't matter since I traded it.
Need to post an update. My brakes will no longer lock my wheels. I recently tried a repeat of my "brake stress test" above, where I apply the brakes hard several times. I go the brakes hot enough to start smelling hot, but at no point could I lock the brakes.
Troubleshooting to follow. My first suspicion is the sliders. I suspect that the grease on the sliders has dried up, and I'm only getting braking from one side of the caliper. When I get a chance, I'm going to re-grease the sliders.
BTW, how long does it take for a thread to get archived?
Sliders Needs Brake Grease. If you use any other grease most will attach the rubber and make big problems. Clean wrong grease of rubbers won't help. Must Replace the rubbers and clean everything else and lube w/ brake grease.
Coat sliders and the caliper holes w/ brake grease.
Brake grease will not dry out but others can. Slider w/o enough lube can "weld" in the holes when water get in there.
Originally posted by theogre: Sliders Needs Brake Grease. If you use any other grease most will attach the rubber and make big problems. Clean wrong grease of rubbers won't help. Must Replace the rubbers and clean everything else and lube w/ brake grease.
Coat sliders and the caliper holes w/ brake grease.
Brake grease will not dry out but others can. Slider w/o enough lube can "weld" in the holes when water get in there.
I used disk brake grease when I did my last brake job... in Apr 2010. I guess even brake grease will dry out eventually.
Need to post an update. My brakes will no longer lock my wheels. I recently tried a repeat of my "brake stress test" above, where I apply the brakes hard several times. I go the brakes hot enough to start smelling hot, but at no point could I lock the brakes.
Troubleshooting to follow. My first suspicion is the sliders. I suspect that the grease on the sliders has dried up, and I'm only getting braking from one side of the caliper. When I get a chance, I'm going to re-grease the sliders.
BTW, how long does it take for a thread to get archived?
Sliders Needs Brake Grease. If you use any other grease most will attach the rubber and make big problems. Clean wrong grease of rubbers won't help. Must Replace the rubbers and clean everything else and lube w/ brake grease.
Coat sliders and the caliper holes w/ brake grease.
Brake grease will not dry out but others can. Slider w/o enough lube can "weld" in the holes when water get in there.[/QUOTE]
Problem with any type of grease is that the grease can and will get brake dust any anything else in it, For sliders use high temp grease, especially if you race. Brake grease is good for normal driving, but not for extreme driving.
Originally posted by randy86: Problem with any type of grease is that the grease can and will get brake dust any anything else in it, For sliders use high temp grease, especially if you race. Brake grease is good for normal driving, but not for extreme driving.
I thought brake grease WAS high temp grease. I thought that was how it didn't dry out as fast as "regular" grease. Here's a photo of what I used:
The label on the grease specifies that it's good to 600°F.
[This message has been edited by Formula Owner (edited 07-20-2019).]
Originally posted by randy86: Problem with any type of grease is that the grease can and will get brake dust any anything else in it, For sliders use high temp grease, especially if you race. Brake grease is good for normal driving, but not for extreme driving.
Dust is a problem? 88 slider boots should keep most any dirt and water out and also maintain the clearance between slider and caliper when brakes are "off." O-rings and slider boots for 84-87 Fiero and Many others do same job plus o-rings are the "return spring" for outer pad as covered in my cave. Not much of a spring but keep outer pad from dragging.
Wrong lube can swell rubber in either system causing binding pads and Worse like No lube or wrong lube in the sliders then expect dissimilar metal corrosion that can and does "weld" the caliper to the sliders. Often to the point that even beating or pressing the sliders out of the hole can be very hard and likely ruin the calipers. This is why GM and others made this an issue in most Factory SM. This is why most steel bleeders will weld them themselves into aluminum calipers and more so w/ bleeder w/o rubber covers to keep water out of the bleeder.
Permatex Brake Grease that you find in most auto parts store Will Not: Suck in dirt into the sliders or most other things. Brake dust and worse can cover the brake grease but cannot migrate into the parts. Wash off. Not even if you pressure wash the car unless you maybe manage to hit the brake parts directly. Run in high heat. Melt until the parts are often way over the Dot 3 4 and 5.1 Brake Fluid Boiling Point. And most cars have enough water in the fluid even fails to meet Wet Boil temp.
And that's Green label Permatex Brake Grease. They now have "Ceramic Extreme Brake Parts Lubricant" claims works from -50°F to 3000°F available in brush cans (24125) and tubes (20354).
Unlike Most other greases including Many High Temp and Full Synthetic Oil and Grease can do any or all of that and make brake rubber parts swell or break down.
I've been using Permatex Green Brake Grease for 35+ years on all kinds of brakes including Big Commercial Vehicles that very hard on brake everyday and Never have problems with the Brake Grease. Unlike having to fix brakes done by others w/ no or wrong lube. Many morons even use Anti Seize in the sliders and other parts that never meant to lube anything. Many use standard or "Dielectric" silicon grease but they are wrong lube here too. Most have Silicon Oils in the formula that run, often in a few months even when cold, and won't protect.
I re-greased the sliders on the front calipers today. I would have done the rears, too, but the ^&%$ slider boots took up too much time. The fronts do most of the braking anyway. Anyway... no difference that I can tell. Feels exactly the same.
I also notice that my brakes creak. They did this before I installed the Thermoquiets, but stopped once I put them on. I wasn't sure if it was the pads or the repair I did during that brake job. I found a missing thrust washer on one rear caliper. That prevented the rears from adjusting properly. The pedal feel was crap. After I fixed that, and put on new pads, the pedal felt MUCH better. I suspect the pedal feel improvement was due to the repair. Currenlyt the brake pedal still feels good, like it did right after putting on the Thermoquiets, but they no longer have the same bite. I'm guessing that after a few hundred heat cycles, the friction characteristics have changed. For the worse.
I've been using T/Q pads on my 86 for years with no problems including no black dust. About a year ago, maybe longer, I thought they stopped making T/Q for the Fiero and came up with a substitute pad & new part number. Think I'll check those old numbers just to make sure..
Spoon
------------------ "Kilgore Trout once wrote a short story which was a dialogue between two pieces of yeast. They were discussing the possible purposes of life as they ate sugar and suffocated in their own excrement. Because of their limited intelligence, they never came close to guessing that they were making champagne." - Kurt Vonnegut
I am using TQ pads and they work fine- I don't race or anything but do go out and carve canyons sometimes. I must say tho that I park the car inside and rarely drive in the rain.
As far as the front locking and the rears not doing their job, I converted my 85 to an 88 subframe/suspension/brakes, then converted the front to 88 calipers with 12" Vette rotors...At first it locked the fronts without touching the rears- I then started messing with the prop' valve; I at first converted to an 87-88 prop valve plunger, and the SOFT spring (I don't remember the year) still front biased, so then, after much smoke out of my ears, I installed the STIFFER spring with that 87-88 plunger....Now it stops well and if I am on slightly slippery surface and try, I can lock up all tires. (I don't try on good surface- don't want to flat-spot the tires)
NOTE; You can swap in ANY prop' valve plunger- you must just use the corresponding plug with it.....And the plug has different spring-perch sizes also, between the large early springs and the later, smaller springs.....all of the valve bodies will accept any year PLUG (Tho the plugs differ in wrench size)......
An update. Apparently, my proclamation of failure was premature. I've driven my Formula to work every day this week, and it SEEMED like the brakes were getting better. So I tried another high speed brake test today. My ride home was down an interstate, then an exit pretty much straight a long straight road. I.e. my brakes should not have been remotely hot at that point. I got up to 80, then braked. I was able to EASILY lock the brakes on the first try, with plenty of additional pedal force available. The re-greasing of my sliders did the trick, even better than I'd hoped. Now I need to re-grease the rear sliders. Might as well get both ends working as they should.
quote
Originally posted by theogre: Permatex Brake Grease that you find in most auto parts store Will Not: Suck in dirt into the sliders or most other things. Brake dust and worse can cover the brake grease but cannot migrate into the parts. Wash off. Not even if you pressure wash the car unless you maybe manage to hit the brake parts directly. Run in high heat. Melt until the parts are often way over the Dot 3 4 and 5.1 Brake Fluid Boiling Point. And most cars have enough water in the fluid even fails to meet Wet Boil temp.
I've been using Permatex Green Brake Grease for 35+ years on all kinds of brakes including Big Commercial Vehicles that very hard on brake everyday and Never have problems with the Brake Grease.
Looking on Amazon, the Permatex Green and the CRC grease I posted a posted a photo of... appear to be about the same. Same temperature range. My bottle shows a max temp of 600°. The Amazon page for the CRC grease shows 400° now, just like the Permatex.
quote
Originally posted by theogre: Unlike having to fix brakes done by others w/ no or wrong lube. Many morons even use Anti Seize in the sliders and other parts that never meant to lube anything. Many use standard or "Dielectric" silicon grease but they are wrong lube here too. Most have Silicon Oils in the formula that run, often in a few months even when cold, and won't protect.
I remember when I bought the grease in the photo. At one place, an employee tried to sell me Disk Brake Quiet. I told him that that stuff is sorta the opposite of grease. He looked puzzled.
[This message has been edited by Formula Owner (edited 07-26-2019).]