Decontaminating Brake Pads

I just installed a set of Hawk HPS pads and new rotors. The rotors came in bag with a type of oil which I assume was an anti rust inhibitor. I cleaned that of using brake cleaner. However, the car doesn't stop very well. I can't even engage my ABS where I've heard that I should be able to lock the wheels with this setup. I'm guessing that I need to clean the rotors better. However, I need to decontaminate the pads. What is the best way to do this? I've been told to wash them with hot soapy water and then heat dry them. What about sanding the surface?

I'm not familiar with the Hawk HPS pads. Are they supposed to be a high performance track pad? I had a set of track pads on my Stealth twin turbo that were downright dangerous on the streets (LOOONG stops), but get a few laps on them and some heat in them and they worked great! Maybe the HPS pads need some good heat in them to be effective?

-Rod

Hawk makes track pads but these are street pads. They don't need to warm up like a track pad does.

Chances are your pads have not been contaminated by the storage oil that was on the rotors. There simply is not enough oil present to contaminate pads (especially after you have cleaned them). Lots of mechanics install new rotors without cleaning them and do not have difficulty.

Severe oil contamination actually often produces brakes that are too 'grabby' and actually work too well. Generally, though, if pads are too oil-contaminated to work properly, they are garbage and must be replaced.

I think you have another problem, such as seized calipers, incorrect pads (for your application), or glazed pads.

New pads may 'glaze' when new if they are used hard and heated up quickly when they are new. Some (but not all) pads require a gently 'break-in' procedure where the pads are applied gently with minimal heat build - up for the first few trips in the car.
If the pads are used hard right from the start, they will develop an excessively smooth, hard surface, which is too slick to develop sufficient friction when used.
Try removing the pads and buffing the wear surfaces with sandpaper, to break the glaze. Also, check or replace those calipers, if you re-used them.

Try to break them in (once you're sure everything is functioning correctly of course) and see if they improve.

On my bike brakes dragging them to get them hot does wonders. Not too hot though, you still want to be able to stop.

Well, I doubt the calipers have sized. They are fixed calipers and they worked perfectly fine with the Axxis pads I removed. As for bed in, I followed the Hawk bed in instructions precisely. They are the right pads as well.

Well, I doubt the calipers have sized. They are fixed calipers and they worked perfectly fine with the Axxis pads I removed. As for bed in, I followed the Hawk bed in instructions precisely. They are the right pads as well.


How worn were the old pads?

Remember when you move the piston all the way back in there is potential to damage the seals, and expose rusted or pitted cylinder walls.

Also, simple question, did you bleed the brakes afterwards?

It is amazing how much bad, ugly fluid can accumulate in the cylinders, and this gets pushed back into the system when you install new pads.

Remember when you move the piston all the way back in there is potential to damage the seals, and expose rusted or pitted cylinder walls.

As Moppie says, neglected calipers that work "fine" often go bad once you push the pistons in to install new pads.

There wasn't much wear on the old pads. I was getting rid of them because of the fact that they dusted a lot and that dust was very corrosive. They had only been in less than a year. I am sure the fluid should be replaced though I don't think that is the full issue here. I have already checked the boots as well and they look good to me.

Like the brake dust, contaminated fluid can be quite corrosive. Brake fluid is hygroscopic (readily absorbs moisture). Moisture and machined surfaces don't mix well....

We've all got to think outside the box. These folks are providing you with their years of experience, you're disqualifying their suggestions by saying, "The boots look okay, so everything behind the boots must be too."

Since you say the calipers are not floating, I suspect you're working on your Stealth. In the 4 years I owned my '93 Stealth TT I replaced the brake piston boots twice due to cracking. They are hard to find and in short supply. Either they rarely had issues (I know that's not the case from the 3S enthusiast sites) or they didn't make enough for the eventual demand.

-Rod

I'm not discrediting anyone. I just don't think that the fluid is the root of the problem. I also don't think the boots are cracked because I pulled out front pads and rotors where the car was stopping just fine to stopping that is on par with cheap Autozone crap. Now, I'm also not saying that the fluid doesn't need to be replaced either.

I'm not discrediting anyone. I just don't think that the fluid is the root of the problem. I also don't think the boots are cracked because I pulled out front pads and rotors where the car was stopping just fine to stopping that is on par with cheap Autozone crap. Now, I'm also not saying that the fluid doesn't need to be replaced either.

So back to the beginning.
The problem is the pads aren't biting like you'd expect them to?

Exactly.

Like I said, I pulled out Axxis Ultimate pads and they were stopping the car great. Now I put the HPS pads they stop worse than any of my other cars. It stops and it stops fine, it's not dangerous or anything. I just would have expected more performance.

Now, I have talked to guys over at 3Si that have used these pads and say that I should be able to lock the tires. Now, they came to the conclusion that it was the anti rust inhibitor. I just wanted some fresh perspective.

To be honest I have ordered some ATE Super Blue fluid, and SS lines anyhow. Also, how would I check for cracked boots? I have looked them over visually and they look completely fine.

You'll like the SS braided lines, well worth the price!

The dust boots for the pistons get hard and show signs of cracking/splitting. You may need to massage them a bit to determine if the rubber is brittle.

Also, the snap rings that hold the boots in place pop out of their channel pretty easily which could allow debris to get behind the boot as well, so make sure the snap rings are securely seated. For your sake, I hope the boots are fine since the stock of new boot kits may be depleted by now. Unless you're looking for an excuse to upgrade to the Porsche/Brembo or Stop-Tech big brake kits. If you do need a brake boot kit and can find one, the OEM kit comes with the two different sized boots and snap rings for one front caliper.

To minimize the liklihood of the calipers being the issue, you could try compressing one piston at a time. What I noticed on my Stealth was if I compressed one piston at a time with the bleeder screw closed, the neighboring piston would move out slightly. If I distributed the force across two neighboring pistons, again with the bleeder closed, the opposite two pistons would move out a bit. This is one way to make sure all four pistons in the calipers are not sticking, at least sticking at their current positions.

I do suggest opening the bleeder screws though when compressing the pistons rather than forcing the fluid back into the brake system.

When you install the SS hoses, flush the entire system like it sounds like you plan to do.

Did the new rotors have an obvious non-directional pattern to the braking surface? If not, there's a chance you may need to get a light machining done on the rotors with a non-directional surfacing to get a good braking surface. After using the brakes currently, is there an almost sweet burning odor? I remember it as being somewhat similar to movie theater butter popcorn smell when the rust inhibitor was burning.

-Rod

You know guys, I feel bad. I took the car out again today and it seems the brakes are slowly getting better. Granted the pedal does not seem as firm. Then I got to thinking about everything that has been said and I forgot something that happened about a week before I changed to the new rotors and pads, I got some high speed fade at about 80MPH. I'm wondering of the fluid in the pistons boiled and when I pushed them back I pushed air back into the lines causing part of this? Granted if that's the case a simple bleed would fix it but I think it's high time to just flush the system and put some better fluid in with some SS lines. Also, who knows how old that fluid is could very well be the OEM fluid

Shorod, I'll have to double check again then. I do recall when changing to the new pads I had to push each piston in two to three times as they kept pushing others back out. As for rebuilding, I was thinking about having Maximal Performance powdercoat a pair for me and he rebuilds them as well. To bad about the seals though. Could be a great excuse to move to a set of Stop Tech's eventually.

Thanks for all the advice guys. I'm going to give all of your suggestions a try and see how it goes.

When compressing the pistons I had good luck using my large Chan-L-Lock and a custom cut block of 1x4 wood to distribute the force over two pistons. Then, with the Speed Bleeder open 1/2 turn, compressed two pistons at a time with the block of wood. Move the block and pliers to the other two pistons and compress them as well. If you don't have Speed Bleeders and open them, this won't work nearly as well.

If you have an old set of brake pads, one old pad will work great in place of the piece of wood.

-Rod

I believe that you have some very aggressive pads there that work best when they're hot. This used to be the deal with metallic shoes on drum brake set ups.

I would pull the pads and see if they're glazed up. You should be able to break the glaze rubbing them on some 80 grit sand paper. Next, if the rotors are glazed, have them cut, but don't shoot for a fine finish, they should be uniform but with an overall coarser finish. I used to hit mine with an orbital sander while they were still on the lathe, both sides while it is turning.

Bleed the brakes too, flush out the whole system and get something that is higher performance than a DOT3 brake fluid. Use brake lube on all your metal to metal contact surfaces and you should be good to go.

Bob