Interesting Rotor Change

[mholhut]

In prep for my club's 1st auto-x of the season, I had to swap out the dangerously warped rotors on the front of the car. These were just changed after the '01 Convention track day at Hallet where I installed Autozone's rotors and their Albany pads. Autozone had 2 cheapies in stock that come with a 90 warranty... I'll see if I can't bend these in that amount of time wink

Anyways, the right side goes on without a hitch, but I did notice that the inner portion of the rotor was worn more than the outer portion. The left side was a bit more interesting. After loosening the caliper bolts, I was unable to remove the caliper. That's when I noticed that the outer pad shim had come loose and had gouged a ravine into the hub area of the rotor. I had to bang the caliper off with a hammer to free the pad from the rotor!!! I didn't measure how deep the crevase was, and I have no idea how long it'd been that way. My guess, for a month or two at most. Before I removed the pad and rotor, I took some shots with my camera for posterity reasons. My next endeavor is to bring the parts back to Autozone and show them what happened. Maybe, but doubtful they can do something for me in regards to a partial refund. Does this sound possible, that a pad defect could warp a rotor? Then again, I'd have to reinstall the rotors and pads without the shims to see if the shim was causing the wobble or not.

So, word to the wise out there kiddies.... don't use any brake pad shims that come with the pads wink

 

[SHODWN]

What kind of a wobble? its funny you say that I have all 4 brakes off the car and my albany pad shims were all trashed. the left side was the worst, the shim came loose and slid down in to the rotor gouge mine. it was the left inner shim on mine that was bad(the worst)

But I have a wobble ever since I installed the new wheels, maybe just noticeing it since I installed them. I could get a little side to side action when the whole unit was off the gound. the tie rod and ball joint is new. was your shim bent like a U mine was and could have caused the small spring action in the side to side since the whole unit was not flat

 

[mholhut]

Kirk,

What kind of wobble? Step on the brake and the steering wheel turns back and forth about 2" in each direction. Hold the wheel tight and the whole front end of the car shakes violently! That kind of a wobble wink

My worst was the left outter, but it didn't touch the rotor surface, just the housing that bolts up to the spindle or hub. Wonder if that's why my mileage has been crappy as of late.

My shim was not bent. It looks like the adhesive melted with brake heat and slid down the caliper and grooved the hub part of the rotor. The shim was equally as worn from contact with the rotor.

Anyways, I put the Raybestos PG Plus's back on that I took off at Hallett and they seem to stop like mad now. Have to wait until I heat them up at the autocross to see how much fade they have.

PS... go to bed!

 

[SHOZ123]

I had a bad woble on mine untill I replaced the rotors. You need to get them trued up on the car.

 

[mholhut]

SHOZ123:
I had a bad woble on mine untill I replaced the rotors. You need to get them trued up on the car.

How do you true a rotor? I know how to true a bike wheel, but not a rotor...

 

[Croaker]

True them on the car? I didn't think that was possible (I'M NOT A MECHANIC). I thought they ground on them to make the even and take out the high spots.

Correct me if I'm wrong.

-Kevin

 

[mholhut]

I think "trued" is the incorrect term. I think he meant "turned." By Ford specs, the rotors should be turned while on the car... and yes it can be done. But, I wouldn't waste the money.

 

[stephen newberg]

Is it more expensive to turn them while on the car than to have them removed to be turned? I have had it done on the car at least once, but since it was a warranty job I do not know what it cost. It was my impression that the reason for turning the rotors while on the car was to save the time and labor of the removal, not that it was inherently a better way to do the job, or is there actually some other advantage of doing it while they are installed?

pax, smn

 

[sdpatt]

Compared to the two brake pad brands mentioned above, you would probably greatly enjoy the performance increase from using Performance Friction Carbon Metallic pads. They come with a lifetime replacement warranty from AutoZone and only cost about $35. If the rotor was worn unevenly between the two faces, it is probably due to uneven clamping pressure from the caliper. Make sure the sliders are lubricated and moving smoothly.

The rotors will last longer without warping and cracking if they are more gently heated and cooled during their early life on your car. Hallet would not have been a good place for this easy break-in. How much do you torque the wheel lugs? I don't have the specs on the Gen IIIs, but the numbers for the Gen I-II SHOs is 85-105 lb-ft. The use of greater torque can create a rotor warping situation.

 

[SHODWN]

I would try them if they made them for the Gen 3, I went through a hour lond ordeal with AUTOZONE yesterday. They have them listed but nobody has them, the whearhouse said they were not available. but they did list them for the 98 with the 601 number, I grabbed them and yup they were 601's (601 is the SLO pad) then they also have them listed for the 99 under 765 I think grabbed them and they were the 601's again. The 598 are the only pad that I know of that will work. SO anyways I went to PEP boys to try there Raybestos PG PLUS, I bet I can burn these off qite fast like the albanys.

 

[mholhut]

Stephen,

I don't really know if it's more or less expensive to have them turned on or off the car. But figure this... has any work done by any Ford dealership, been LESS than expensive?

Scott,

Like Kirk said, it seems difficult to find these in the correct size for our cars. I had a set on my '94 and liked them very much. Also, the PG Plus pads and Bendix rotors I had on the car at Hallett had been on the car for several months... as well as 1100 miles of "gentle seasoning" on the ride out there wink My wheels were torqued to 100 lbs/ft per Ford specs. With the new rotors I just put on, they are now at 70 lbs/ft. Sliders were lubed liberally pre/post Hallett and were still free moving this rotor change.

Kirk,

The PG Plus isn't too bad of a bad. I had over half the pad left when I took them off the car after Hallett, which is why I'm using them now. Compared to the Albany's that Porter cooked off his car last summer, these held up pretty well.

 

[SHOZ123]

I always use Ford OEM pads. They come with the shim andd have never become disloged.

And yes I meant "turned on the car". This is suppose to accomidate runout caused by the hub/rotor assembly.

 

[AutoSHO]

I'm surprised nobody mentioned this, btu I bet the reason the rotor was warped was because the shim was holding the pad against the rotor. If you had to "presuade" it off with a hammer, then it has a little constant pressure on the rotor, which would generate a lot of heat, and in turn, warp the rotor. Just my .02 cents!

 

[mholhut]

Well, that would explain why that set warped, but not the previous two sets wink I'm starting to think it might be something with the brake bias.

 

[SHODWN]

HUH? well yea if its not working.. how was my briaking when you drove mine compared to yours?

 

[stephen newberg]

"I don't really know if it's more or less expensive to have them turned on or off the car. But figure this...
has any work done by any Ford dealership, been LESS than expensive?"

That was not great English, Kirk. Less expensive than on or off the car?

Obviously I do know what you mean, and yes, in some instances it actually has been cheaper to have the Ford dealership do something than to have it done at one of the local shops we have that are similar to Autozone. I do not know how Autozone works, but here places like Canadian Tire charge a flat time rate times however long it takes to actually do the job, plus parts. Parts are, on occasion, cheaper at such places than from the dealership, though not often by much. They are very often of lower quality to go along with being cheaper. The real difference is in the mentioned labour, which bills out at a higher rate at the dealership, but also bills at what the job is book rated for, not how long it actually takes. So on simple, fast jobs, the Canadian Tire type places are normally cheaper. On anything long or touchy, the dealership is likely to actually cost less.

Of course, for this to work it also requires that one not to walk into the dealership with the attitude that they are the enemy and out to cheat you. I have noticed that some find this difficult. wink

pax, smn