caliper/rotor adjustment

[shyfty]

okay, I ran a complete search of this site, checked Chilton's, Haynes...not even the FSM had any info on this:

I replaced my calipers (when I ordered from the local parts store, I thought they'd be new, but they were rebuilt ones). the picture explains my problem. I had my rotors turned, too, so I took note of exactly how everything came off, and I put it all back on the same way. this rebuilt passenger-side caliper...the outer half is riding on the rotor. I don't know much, but I know that's not good..plus being that I can't get the pad in. anyone know what to do?

btw, on the subject of pads, when i removed all the hardware (pins and anti-sqeal shims/springs) I noted that I am missing a shim/spring for, yes, the passenger outer pad. the guy at the store said I didn't need it, but when I pre-installed the pads/hardware, that pad was flopping all over the place. I bet it'd get to sqealing, too. anyone know where I could find just much?

[2ManyZs]

You can get the brake hardware kits from MSA for a very reasonable price. New pins, clips, shims and all....

As to the problem... hmm... haven't seen one like this either...

The first thing that comes to my mind is the disc is not seated on the hub correctly, or is not torqued down enough. You didn't by chance put a washer between the rotor and the hub by mistake did you? Or one between the caliper and the mount? By what little it is off, it almost looks like a possibility.

Does it do this all the way around the disc? The only reason I ask is if it only does this in one spot, the rotor is likely warped. Now, you say you had them turned, so this shouldn't be a problem... but.....The only other possibility is that the caliper is the problem, perhaps someone ground on the mount for some odd reason and messed up the offset? That's one of the problems with buying rebuilt or reman, you never know what they started with, it could have been a piece of junk to begin with and should have been scrapped.

My money is on the rotor not being seated flat all the way around where it mounts on the hub. I have seen them try to sit unevenly and only after torqueing them down do the mount flush with the hub. When you draw the bolts down, it is best to do it in a criss-cross pattern like you would on your wheels, the rotor has to fit tightly over the raised flange on the hub and if not done properly it will either not slide over the flange or will end up at an angle.

[shyfty]

okay, I went back and pulled the whole hub assembly just to make sure.....but it's all correct: no extra washers or anything, and it's sitting perfectly. the hub-to-rotor alignment shouldn't be off since I didn't take that apart to have it turned (asked the guy, and he said I didn't need to do it...so I didn't:geek: ), but yes, it rubs the whole way around.

I do have a half-brained idea to fix this, but I'm not sure of the tensile strength of the steel: the idea is to grind down (about an 1/8") the caliper-to-strut flanges/mounting surfaces/whatever. then, when I bolt it on, this should give me the necessary clearance. anyone against this?

[2ManyZs]

If it didn't do it before with the old caliper, don't do anything to compromise the car. Take the caliper back and have it exchanged first and see if the next one works or not.

I'm also wondering about the rotor, never heard of anyone doing them while still mounted to the hub unless he did it on a milling lathe such as he'd do a flywheel on?

I'd exchange the calipers.. then see what happens.

[Bambikiller240]

My bet is on the Caliper being the problem also.

It is hard to tell from the picture, but I'll ask anyway. Is the rotor "relatively" centered inside the caliper? Or is it WAY off to one side? The reason I ask is that I'm wondering if they may have given you a caliper for use with vented rotors which I don't believe would be compatible with non-vented rotors.

I could be way off base with that idea, but as 2ManyZ's says if it wasn't like that before (and you have verified correct assembly).........don't alter anytrhing. It almost has to be the Caliper. If you have the old caliper, I'd take some detailed measurements and see how they compare.

[26th-Z]

My bet is on the caliper too. I'm dy'in to find out what happens.

[shyfty]

well, I'm assuming that it's because these are remanufactured calipers that I had to give the parts store my old ones. the store opens in an hour, so I'll take the caliper and check on that vented rotor thing. that seems the only feasible answer right now, though from memory, these look exactly like my old ones.

thanks for the lead.

[2ManyZs]

I don't know that they look like they are for vented rotors.. but, if you are putting these on a 280 they might be 240 calipers and the slight difference in the hubs might be the difference.

But, if you are putting these on a 240 and they were 280 calipers, seems like they would be rubbing on the other side of the caliper.

Ya got me on this one....

[shyfty]

Originally posted by 26th-Z

My bet is on the caliper too.

sorry guy, House wins...

so, I trekked on down to the parts store. the guy wouldn't let me borrow the old caliper, but we did compare the two: except for the old one being really dirty and a little rusty, they're exactly alike. still at a loss, and not being able to think of anything else at the time, I slipped on the drivers-side caliper (upside down of course) to make absolutely sure that it would be the caliper. it wasn't. this other caliper rubbed, too.

being bored, and having a measuring device in hand, I checked the thickness of all the lobes: the calipers' are the same, but the driver's side (on the strut) are thinner than the passenger's side. ???

new idea: instead of the butcher job of grinding down the lobes on the caliper...how about an 1/8" worth of washers between the hub and the rotor? there's a whole 1/4" of space on the inner side, so this should even it out. and if tightened down good this should be still safe, yes?

..I've probably taken everything off and put it back on close to 10 times. this is making me feel like this guy ---> :sick:

[Bambikiller240]

Well, I'm not convinced it is not the caliper just yet. I cannot imagine why the parts person would not allow you to "borrow" back the cores if you let him hold the new calipers, or if he made you leave a cash core charge with him as a guarentee of their return to the store. I still think that I'd return the new calipers and get my money and cores back. Reinstalling the cores should tell you if you have done something wrong. I don't know your parts guy, but many of the ones that I encounter don't impress me with their knowledge of cars, especially older cars. I'd be considering acquiring my calipers from a different source if the cores go back onthe car properly.

[LanceM]

If you do go the washer route be sure to use hardened washers, regular steel washers will crush over time in an application like that allowing the caliper to come loose.

[2ManyZs]

Definately have to use a hardened steel washer... but... unless I'm mistaken, putting a washer under the mounting bolts is going to move it in the wrong direction and make it even worse isn't it?

I'm with Carl, go get your money back and get your cores returned. Then either go find rebuilt calipers that work, or rebuild the ones you have... it's a very simple job and parts are readily available, you should be able to find new pistons if you need them, so rebuilding the old ones is an easy task.