Brake Rotors

[tjpops]

Now that you've all helped me with transmission issues - it's time for my next conquest - brakes! My front rotors are warped and I'm led to believe this is another weak spot (at least on my '92). I'd appreciate knowing how you folks are dealing with this. Are you replacing with stock rotors or does anyone have experience / advise re: 3rd party rotors that stand up better?

Look forward to your replies!

If your rotors are too warped to be turned, I would suggest

http://www.appliedrotortechnology.com/

I have read post about other SVX owners that have installed these, and they have had no complaints.

[svxxx26]

tj, I'm probably in the minority here on this, but I haven't had any warpage problems with the stock rotors in the 5 or 6 years I've had the car. On the other hand, you probably wouldn't call my driving style that aggressive.

The bottom line is, what's your driving style? If you're not into the brakes hard and heavy, as in from high speeds to a stop in a real short time, I'd save my money and stick to the stock rotors.

However, if you do like to drive in a very "spirited" fashion, warpage does seem to be a problem.

The two most common forms of warping rotors.


1) splashing through puddles under hard breaking - water splashing on hot rotors is the #1 cause of warpage.

2) riding your brakes all the time when you drive


tj. I would take your car down and have the rotors turned and get new brake pads before I would do anything else. If your rotors are damaged, then I would consider the ART rotors, they are cheaper then the stock ones, and are of better quality to resist warpage.

[Hangtownsvx]

After getting no satisfaction from drilled rotors, I got some cryogenically treated rotors (stock Subaru) in November. They started pulsing in mid December, about the same time frame as the drilled rotors lasted. I am not hard on brakes with my other cars, in fact sort of easy. I recently read the big brake article in Grass Roots Racing magazine and they implied that stock systems should never warp. No clue there. I am still searching. I don't have stock wheels and my mechanic wants to put the blame there. Maybe we need to do a poll on the wheels that people are running. We should also get temp sensitive paint to see what our temps are on the rotors.

[Hangtownsvx]

We just measured the front and the rears and the fronts were .001 out and the rears .004, so maybe the unfrozen rears are now the culprit. The temperature paint on the fronts is orange equating to 800 degrees, not too bad for a heavy car. Maybe I will do a cryo treatment to the rears.

[mohrds]

I'm looking to replace my rear brakes before the trip to Reading. I've ammased the following part numbers:
(2) 26310PA061 Brake Disk Rear Rotor/Drum combo
(1) 26296PA040 Pt130697 Brake Pad Kit
(2) 26298PA000 Brake Shoe (Parking Brake slave)
(1) 26257PA000 Brake Shoe Rh (w/Parking Brake Cable attachment)
(1) 26257PA010 Brake Shoe Lh (w/Parking Brake Cable attachment)

My questions are does part 26296PA040 contain 4 pads, 6 shims and 4 clips?
Second, part 26257PA010 shows up as discontinued. Anyone know a valid part number for the LH parking brake shoe?

Doug

Buy EVERYTHING from autozone....

I just exchanged 4 year old brake pads for my Honda at autozone... They sell these things with a lifetime warranty..

Now unless you just hate doing brakes and never want to do them again i would put this up for consideration as the best way to beat the warped rotor problem...

PAUL!

[Hangtownsvx]

I have now had the rear frozen rotors for a few weeks and can rule them a success. When installing them, I was surprised to see how little pad life was left. Along with noticing the difference in braking vibration with a down hill application, this makes sense. I think this car has a brake bias more heavily towards the rear than cars I am used to. That is why I concentrated on changing and turning the front rotors with little long lasting success. The warped (.004) rears were contributing significantly.
So the moral is to actually measure the amount of warpage before changing rotors. Less than .002 on the front with less than .004 on the rear is still very noticeable and irritating. They need to be less than .002 on both front and rear.
Note the new rears as supplied from Frozen Rotors may or may not be genuine Subaru. The minimum thickness was stamped in, not cast in as the originals.

[Seraph]

I am not sure about the ART pads and rotors being cheaper though. They cost around 300 right? I got my stock pads and rotors for 170 (pair) from a local shop -- They are organic so they don't squeal. I am happy with the stocks.

Lwin

Thank you. Knowing the purists in the crowd I was hesitant to pipe in that my pads AND rotors are all from Autozone. The rotors are about $65 apiece. Something like a 2:1 with the stock cost. Pilot training has taught me the importance of planning my approach. So I don't have warp problems attributable to slowing down from high speeds. That's not to say I haven't nailed the brakes when a deer crosses my tracks on those country roads. Still, no problems with braking from 80's to 20's just above anti lock engagement.

Heck for the money you could have a spare set of cast irons sitting in the garage waiting for change over after a hard stop from the 100's . Pop off the "Pringled" ones, put on the clean ones and then turn the warped ones down. My general experience is that once you cook a set of rotors the stress is out of them and a turning usually keeps them straight after that.

But it is you $$

[1994SubaruSVX]

but here it is again. if you dont want stock and you want really effective brakes call dayle at motorsportwarehouse and buy the zinc plated cross-drilled rotors from him. i have been using them for quite a few months now and the performance is wonderful. hell i have even raced with them under heavy braking for two days straight and i have no warpage and my pads still look good. my car does not have abs and we did some threshhold braking tests and they didnt even lock up or fail or fade....they are good brakes period. they are not cheap, but you get what you pay for, a front set will cost you around $350 and that includes shipping and the zinc treatment. just call dayle if you want more info.

This may be a bit premature but.... I have a heat treat supplier that performs a process known as "atmospheric nitro-carburizing" on ferrous metals. The process is followed by a molten "salt" quench which oxidizes the surface of the material. The atmospheric portion hardens the surface and the temperatures used are non-critical. What this means is that the substrate material is not annealed. There are several benifits to this process over plating processes. First, the surface is hardened to a shallow case of Rockwell 52-55 on the C scale. Second, the salt quench yields a salt spray corrosion resistance in excess of 200 hours (Zinc is 70-75 hours, if I recall correctly. If I don't I'm sure someone will correct me ) Thirdly, the surface is very abrasion ressistant. By very what I mean is the rotors *don't* wear. I can have this process performed for a similar cost to "freezing" the rotors. The parts must be clean of rust and plating for the process to work.

If anyone is interested in this process let me know and we can do some experimenting.

how long does a zinc-plated rotor normally keep it's appearance?
also, can you re-plated it after it's been plated before?
what is the benefit of zinc? (higher heat tolerance, improved appearance, or both)

1994SubaruSVX:
did you have a problem with warping before you had your rotors/pads replaced? i ask this because there are those out there with stock rotors and zero warpage, while others have stock rotors and a ton of warpage....possibly stemming from other issues.

thanks for the input.
toby

<<how long does a zinc-plated rotor normally keep it's appearance? >>

That depends where you live. In Wisconsin, where we salt the hell out of the roads in winter, about 28 minutes.

<<can you re-plated it after it's been plated before? >>

Yes. But all old plating and rust must be removed first.

<<what is the benefit of zinc? (higher heat tolerance, improved appearance, or both) >>

Zinc resists corrosion and helps keekp the air passages clean. This allows them to cool the rotors more effectively. And it does make them look cool