HPS Pads and Centric Rotors Installed

[FrozenNorthLGT]

This weekend I finally got around to installing my new brakes. I went with Hawk HPS pads front and rear, Centric High-Performance Slotted (Power Slot) front rotors, and Centric Premium rear rotors.

 

The install went well, considering this was the first time I've had any of this apart on this car. I agree with those that say the rear caliper bracket bolts kind of suck, but with the right extensions (6" and 12") they are manageable. Also, make sure to have two M8x1.25x1" bolts handy. I never would have gotten the rear rotors loose without them. The fronts came off nicely though. Since the car has almost 80k on it I decided to replace the hardware for the calipers front and rear while I was doing this. A word of warning to anyone doing this, if you buy the rear bolt and slider pin kit from advance auto, don't use the rubber bushings for the lower rear caliper pins. They seem to be too big, or at least mine were. They fit pretty tight, and actually sealed so well that the pins wouldn't go in all the way. I had to work real hard to get the caliper to swing back down while assembling and this actually caused the calipers to pull the outboard pad into the rotor.

 

I didnt notice this until after I did my bed in procedure, and was driving around cooling things off. I realized the pad smell wasn't going away like it should and pulled over. The rears were smoking pretty good. I let them cool till they stopped smoking and drive 5 miles back home at 20 mph. They were smoking again and super hot when I got back (wish I had my infrared thermometer on me). I was actually worried I would damage my wheels they were so hot, couldnt even take them off without gloves. Fortunatly, I dont think I caused any permenant damage to anything. I replaced the lower pins with the original bushings and all was fine. I blistered/baked the paint off the pads, cooked the grease off that Hawk supplies with their pads, and discolored the paint on the edge of the rotors, but not the hats. Everything seems to be fine now though, no odd vibrations or anything.

 

Now that everything is good, I have to say I'm quite pleased. Bite is better than stock, pedal feel is improved, and fade is harder to achieve than with stock. (I only know that from breaking these in, if you fade these on the street you're driving like a moron...). Also, as far as the squeal some seem to get with these, I have none at all. And I didn't use any of the stock shims. Mine were completely rusted. Ive got new ones on order in case, but for now with just the shims on the Hawk pads, and the "Gear-head" grease...lol. All is quiet as can be.

 

I do have a question for the brake guru types though. Today I went out for a drive to check temps on the rotors just for fun, and I'm not sure if the results mean anything since I cant find any reliable info on this. The first numbers are the starting temps, completely cooled, second set is driving across town 3 miles like normal, third set is driving back aggressively, fourth set is from a 60 mph to 0 stop, and the last set is back up to 60, then coasting down without using the brakes at all.

 

LF-75, 130, 200, 244, 181,

RF-67, 112, 172, 180, 133

RR-70, 143, 172, 304, 182

LR-69, 150, 154, 278, 184

 

I guess what I find odd is that the rears seem to be hotter or very close most of the time to the fronts. The left front is always the hottest, and is hotter by 20-30% than the right front. And the right front, is on average, the coolest of all. Can anyone give any insight on this. I'm by no means an expert on brake temperatures. Maybe a variation of 30-80 degrees isn't that much? maybe the fronts being larger over-all, and slotted, is keeping them cooler than the rears? Can anyone that cared to read all this enlighten me?

 

Here's some pics, not that they're anything people haven't seen...

[wcbjr]

All I can say is that the front of the car has more weight than the rear. And the driver's side more than likely has more weight with the battery and the driver being on that side. That could generate more heat.

[FrozenNorthLGT]

I was thinking that too, but would it be that much of a difference? Or am I making too big a deal out of 30-80 degrees? Someone must know!!!...lol.. I think my thread title is probably not likely to draw the attention of anyone who may know, so Im gonna make a new thread with just my question in it.

[wcbjr]

The temps may settle down later once the pads have fully bedded.

[Max Capacity]

I'm no expert, but I would think the right front is not grabbing that much. I would be looking for a more balanced temp reading.

 

Hey put the wife in the passenger seat with a 30lb block and see if the RF temp comes up....I'm sure she'd do it....

[FrozenNorthLGT]

My GF said "Wife??," but she'll do it...lol. Just gotta wait till friday when Im off again. Ive been keeping an eye on it and its never that much hotter...so maybe weight distribution is all it is.

[FrozenNorthLGT]

The temps may settle down later once the pads have fully bedded.

 

 

Missed your response when I read through first. Thats a good idea too...

[FrozenNorthLGT]

Went for a ride with my GF in the car tonight after work. For anyone thats interested here are the results: First set after a 5 minute easy drive through town (this set was by myself, after this I picked up my passenger), second set 15 miles out of town, country roads, curves, stops, etc, third set after 15 minute cool down, fourth set after another bedding procedure and 5 minutes of cool down driving, fifth set back in town at my apt.

 

LF-159, 200, 155, 370, 188

RF-140, 198, 136, 300, 136

RR-141, 200, 120, 330, 159

LR-135, 190, 120, 315, 161

 

These numbers are a bit closer together I think. At least all but after heating them up good. On that test the passenger front is still the coolest of all.

[PhillyWilly]

I just did this same exact install last weekend. I feel like the stock setup had better bite. I could lock up the wheels with stock and cant now. I have to press the pedal much harder to brake. I still have stainless steel lines and ATE fluid that I didnt get to install yet and hoping that will help. Im a little concerned at why the new HPS and Centrics dont bite as good as stock tho.

[LegacyMUN2k6]

It could be the pads.

[AZP Installs]

The rears while doing less braking have less mass to absorb the heat generated.

 

As for the temp differences, L/R I would say check your sliders and possibly the calipers need to be rebuilt. I wouldn't worry too much about that though.

 

-mike

[AZP Installs]

I'm going to try to snag some IR photos of my Rotors/Pads since my day job is a Thermographer

 

-mike

[darkside]

Try a different set of pads, I had hps pads and hated them, only about 5 percent Better than stock. Hps pads also shit all over rotors, sorry leave deposits like crazy on rotors. Just my 2 cents try stoptech pads or hawk hp plus , much better pads, hp plus have amazing bite but a little noisy sometimes, the stoptech pads are great and are what the HPS should have been. Hps overrated by forums in my book.

[AZP Installs]

We've installed them on at least 400 cars in the past 10 years of working on Subarus and never had any complaints from folks who use them for daily driver and some spirited driving. The HP+ is recommended for track use or serious enthusiasts. They dust a lot and are squeeky. With that said, my daily driven cars all get HP+ but I'm hard on my brakes all the time.

 

-mike

[FrozenNorthLGT]

The rears while doing less braking have less mass to absorb the heat generated.

 

As for the temp differences, L/R I would say check your sliders and possibly the calipers need to be rebuilt. I wouldn't worry too much about that though.

 

-mike

 

I took apart and re-greased all the slides, they move good. I can also push the pistons in pretty much by hand, so I think they are fine. IF I dig back into it ill put some blocks in the calipers and step on the brakes to make sure they come out even. Id be curious to see what you come up with for temps on yours though.