[nm_shooter]

Uh oh.

My front brakes have developed some runout. The warping is not bad, but it is not going to get better, and I don't want to tow with the way it is.

I had planned on doing a brake job tomorrow. Just FYI, the rotors have been machined once already, about 25k miles ago (I've got about 65k on the truck. I received a reply to my question on brake jobs, and it now has me concerned. Here it is:

<font color="red"> </font>
<snip>
There is no minimum machine to spec on superduty rotors because they are not supposed to be resurfaced, they are heat treated, and they will quickly develop hard spots if you machine them.
<snip>
<font color="black"> </font>
Whoa! Can someone verify this for me? I got 25k miles on my last machined set, and they seem to be okay. But maybe the wobble I feel in the wheel is not runout, but maybe "hard spots"?

What do I do? Machine the rotors, or buy new ones? /ubbthreads/images/graemlins/confused.gif

Thanks and regards,

Frank

 

[Pappy19]

Why take the chance. I've heard that they can be turned once and then get new ones. I'd get new ones, slotted, if it was me.

 

[SmokeyWren]

You heard right. Never "turn" the rotors on a SuperDuty truck.

Contact member FMTRVT for details.

 

[mobeydick]

Too late, already done it about 100,000 miles ago!

 

[FMTRVT]

The rotors can be machined. The only thing that Ford by policy and states in the service manual is not to use a bench lathe to resurface the rotors.

If there is a hard spot in the rotor, that area will be thicker then the rest of the rotor, and that can cause some pulsation right away. If not, in time the softer area of the rotor will wear faster then the hardened area and once again thickness variation will cause pulsation.

You can have a fair amount of runout with parallel rotor rubbing surfaces and not have pulsation. But you can have 0.0005" runout and thickness variation and have pulsation.

The goal is to install the rotors and that are machined so there is minimal runout (less then 0.001") so thickness variation will not occur for the life of the pads. A new rotor is best for that, but an on-car lathe is the best service machining method.

In your case you've gotten 40k on the original rotors before needing to be machined. Not too bad. But if the rotors were re-machined with a higher runout then factory (less then 0.001"), the pulsation will come back sooner, like 25k.

Or if there was an issue with the caliper pins or pads sticking, a less then through maintenance job in this area will allow the "sticking" to return sooner, and the subsequent lack of clearance between the pad and rotor will cause the thickness variation to wear in sooner (25k).

Don't forget that rear disc brakes can have the same issues.

 

[j_apetersen]

[ QUOTE ]
You heard right. Never "turn" the rotors on a SuperDuty truck.

Contact member FMTRVT for details.

[/ QUOTE ]

Contacted FMTRVT and he posted yes you can turn rotors and how. so kind of shoots holes in your post dont it. /ubbthreads/images/graemlins/shrug.gif

 

[Ggg6]

[ QUOTE ]
<snip>
There is no minimum machine to spec on superduty rotors because they are not supposed to be resurfaced, they are heat treated, and they will quickly develop hard spots if you machine them.
<snip>
<font color="black"> </font>
Whoa! Can someone verify this for me? I got 25k miles on my last machined set, and they seem to be okay. But maybe the wobble I feel in the wheel is not runout, but maybe "hard spots"?

What do I do? Machine the rotors, or buy new ones? /ubbthreads/images/graemlins/confused.gif

Thanks and regards,

Frank

[/ QUOTE ]

Like was said, yes they can be turned, and I will get the min. thickness for you tomorrow if I can. I can't tonight. Also like was said you must be very careful with keeping the sides parallel.

 

[nm_shooter]

First and formost... thank you to all who have contributed to this thread! The thing about dissent is that you get to hear both sides of an issue, and it really brings the data out.

I called my Ford service person today, and asked if the rotors could be machined. The service guy said absolutely... they do it all the time. If they couldn't, customers would get really pissed having to buy $250 worth of rotors every brake job.

So I decided to take the risk and have the rotors machined. After all, the last time I had them turned I got 25k miles out of the deal, and I don't have much to lose.

Getting the caliper brackets off was interesting. I initially put a 18" wrench on the bolts and they didn't budge. Then I remembered that I had an impact wrench that I bought from a guy at work for $15. I just got my money out of that deal /ubbthreads/images/graemlins/smile.gif

Anyway, the rotors slipped right off, and what do you know.. there is a minimum thickness spec stamped on the backside of the rotor. Hmmmmm.......

Looks like maybe I made the right choice.

Regards,

Frank

 

[NEVRNF]

This information comes from my Alldata

Front Disc Brake Rotor Thickness 1.5 in
Rotor Minimum Thickness 1.417 in
Note: Minimum rotor thickness is molded into the disc brake rotor
Rotor Maximum Runout
SRW 4x2 0.0020 in
DRW 4x2 0.0028 in
SRW/DRW 4x4 0.0015 in

Rear Disc Brake Rotor Thickness 1.181 in
Rotor Minimum Thickness 1.102 in
Note: Minimum rotor thickness is molded into the disc brake rotor
Rotor Maximum Runout 0.0015 in

© 2005 ALLDATA LLC. All rights reserved.
Terms of Use

 

[fordmastertech]

If you really want a longer lasting pulsation free brake job find a shop that can machine the rotors on the vehicle. Just make sure to clean the rotor and hub mating surfaces and apply some anti seize compound to these areas first. Also mark the rotor and one lug stud to index it to the same spot if removal is necessary later. This is the only Ford recommended way of doing it. Make sure to wash the rotors with soap and water after they are machined to get rid of the rotor fuzz that will be left of the surface.
Ford has nothing in print that says you can't machine Super Duty rotors.
FMT

 

[Ggg6]

Thanks Tony that is exactly the dimentions I found this AM. BTW check your PM @ MOB.org

 

[FMTRVT]

Those runout values are too high, and why you would have issues in 25k again.

 

[Fudotpuc]

Uh oh.

My front brakes have developed some runout. The warping is not bad, but it is not going to get better, and I don't want to tow with the way it is.

I had planned on doing a brake job tomorrow. Just FYI, the rotors have been machined once already, about 25k miles ago (I've got about 65k on the truck. I received a reply to my question on brake jobs, and it now has me concerned. Here it is:

<font color="red"> </font>
<snip>
There is no minimum machine to spec on superduty rotors because they are not supposed to be resurfaced, they are heat treated, and they will quickly develop hard spots if you machine them.
<snip>
<font color="black"> </font>
Whoa! Can someone verify this for me? I got 25k miles on my last machined set, and they seem to be okay. But maybe the wobble I feel in the wheel is not runout, but maybe "hard spots"?

What do I do? Machine the rotors, or buy new ones? /ubbthreads/images/graemlins/confused.gif

Thanks and regards,

Frank

I was surprised to learn this. I bought a super duty e350 while driving home every time I stepped on the brake it pulsed and the steering wheel shook. I immediately suspected warped rotors but never had both sides at the same time. I mentioned it to a friend and he recommended checking my wheel bearings. Never heard of that causing this problem. Checked them and was able to turn the nuts almost a complete turn in. Test drove applied brakes smooth as glass. Now wondering how many times I paid to turn the rotors and the bearings just needed adjusted. Of course after turning, the rotors were placed back on the vehicle and the bearings were then properly adjusted. A person wouldn't know unless you check for yourself.