Need rotor/brake job advice

[JamesBond]

From reading your posts it sounds like your "warped rotor" feeling goes away when new rotors are put on, but then returns after a while. If this is the case I would say that your problem is not the hub that the brakes are installed on but something that happens to the brakes during the time afterward.

It could be that your lug nuts are over torqued when you have tire service done. (I always loosen and re-tighten lugs in the parking lot at the tire place btw) Its possible that the way your particular vehicle operates or your driving style is causing the rotors to warp or pad material to transfer to the disc or whatever. Maybe you have a caliper that drags and heats them up. (Feel both sides after a drive)

I have no idea if this makes a difference but when I make a stop at a stoplight I always try to leave some space in front of me and as I'm waiting, I creep up a foot or two every couple of seconds. My reasoning behind this is that it prevents a hot spot on the part of the rotor that ends up between the pads when the car comes to a stop. I'm not saying that this works or that it will work for you, but its what I do.

 

[MONKEYMAN]

Observations:
Lug nuts came off like butter after I torqued them to spec. The drivers side rotor was slightly over .002" using dial gauge. Passenger side was closer to .003". That was the side that had a lug that was extra tight after tire shop replaced tires. Hubs were around .005" or so. Not much rust, so maybe hub is wearing out? Pads were wearing evenly and looked like new. I am thinking of just reusing them. Maybe a combination of worn hub and over torqued lug nuts is my problem. I am going to clean hub and try to phase match my Napa rotors to see if I can get run out in spec. If not plan B is to use Advance rotors I have on hand. Does that sound like a good plan?

 

[MONKEYMAN]

Originally Posted By: JamesBond
From reading your posts it sounds like your "warped rotor" feeling goes away when new rotors are put on, but then returns after a while. If this is the case I would say that your problem is not the hub that the brakes are installed on but something that happens to the brakes during the time afterward.

It could be that your lug nuts are over torqued when you have tire service done. (I always loosen and re-tighten lugs in the parking lot at the tire place btw) Its possible that the way your particular vehicle operates or your driving style is causing the rotors to warp or pad material to transfer to the disc or whatever. Maybe you have a caliper that drags and heats them up. (Feel both sides after a drive)

I have no idea if this makes a difference but when I make a stop at a stoplight I always try to leave some space in front of me and as I'm waiting, I creep up a foot or two every couple of seconds. My reasoning behind this is that it prevents a hot spot on the part of the rotor that ends up between the pads when the car comes to a stop. I'm not saying that this works or that it will work for you, but its what I do.


I have been doing the creeping up a few seconds are two. Maybe I picked that up from you? I know I read it on BITOG. I am more suspect of the tire shop. They are the largest tire chain in my area. It has worked well when I have a flat and a shop will fix it for free when I am working all over St Louis. The downside is when I get my tires rotated they do not check or adjust the tire pressure. Makes me think they are doing it quick and not paying attention to details. Some of the lug were over torqued by a large amount. Maybe they used the wrong torque bar or skipped that step?

 

[mechtech2]

Is there a question in that mess?

 

[MONKEYMAN]

Originally Posted By: mechtech2
Is there a question in that mess?


Sorry for the mess.

Yes, I have a question.

I have a dial indcitor. Both my Napa rotors and new Wearever rotors are reading around 0.003". At this point I think I am just going to go with the new rotors and pads due to time invested.

What would you recommend I do or what am I doing wrong?

 

[Rock_Hudstone]

Originally Posted By: MONKEYMAN

I have a dial indcitor. Both my Napa rotors and new Wearever rotors are reading around 0.003". At this point I think I am just going to go with the new rotors and pads due to time invested.

What would you recommend I do or what am I doing wrong?

.003 exceeds allowable specs for rotor+hub runout for the Saturn. Since the readings are indentical with both rotors I'd suspect the hubs. Also check for dragging as mentioned.

Here is a good link on the subject:
http://www.saturnfans.com/forums/showthread.php?t=176831

 

[yonyon]

If you have four rotors and whichever rotor you put on the hub you can't get closer than .003" it's probably time to pick up a rotor shim. Have you checked the hub for runout? Keep in mind that runout increases linearly with distance from the axis or rotation, so, e.g. .001" runout on the hub face 2.5" from center will create .004" runout at the edge of a 10" rotor. If rotor shims aren't available for your car you may be able to drill out shims made for another application or yank the hub and get it trued up on a lathe.

 

[Rock_Hudstone]

Originally Posted By: yonyon
Keep in mind that runout increases linearly with distance from the axis or rotation, so, e.g. .001" runout on the hub face 2.5" from center will create .004" runout at the edge of a 10" rotor.

Right, thats why runout should be measured at the outer edge of the rotor.

I'd also check hub end play.

 

[MONKEYMAN]

Hubs are tight. I was able to get one Advance rotor to measure right at .002" on drivers side. Then went to passenger side and it was .004" or so. I was disappointed. Tried the other rotor with similar result. It looks like that is the problem hub. I looked at shims before but did not have the dial indicator working. Hub run out was .005 " or so. I cleaned them up after measuring. Think I will put old rotors and pads if I can not find a shim today. Then get the appropriate shim for passenger hub. I can do without the new pads and use that money to get a shim. I did measure runout close to edge of rotor or hub. I have the feeling I clipped one to many curb.

 

[MONKEYMAN]

Thanks everyone! Just ordered some shims from Rock Auto. Passenger side rotor is still double the runout it should be. I am getting some guidance from the technical guru at Saturnfans. I will report back when I have some good news. Everytime I work on a car I have more respect for those that do it for a living.