Brake Rotors

After replacing my rotors I now have a clunking (both heard and felt) in the front end as I pull away or back out at low speed .. sometimes it is noticed as I begin to apply the brakes while stopping or slowing. I had the front end checked out and have narrowed it to the brakes. Everything seems to be in order but notice that there is some play in the rotors .. they are not tight to the hub .. is this normal? I have tightened all the bracket bolts and the caliphers are attached securely. Can anyone help with this?

First, did you buy economy rotors? There is a huge problem with a bad champfer on cheap rotors. The angle is wrong and the rotor doesn't sit squarely on the hub mounting surface. That cocks the rotor a bit. You can tighten the lug nuts, but the rotor will ride like a warped record and knock the pads at every revolution.

Wagner, Raybestos, Bendix, NAPA/United offer professional grade brake rotors. If you really want to be sure you're buying quality, only buy rotors that are D3EA certified.

Here's a link to a Raybestos video demo that talks about the differences between economy rotors and premium rotors. After watching it, you'll never buy economy again.

http://www.raybestos.com/wps/portal/raybestos/kcxml/04_Sj9SPykssy0xPLMnMz0vM0Y_QjzKLN_SOD3YFSZnFh8Qbmx jpR2KIGSLEfD3yc1P1g_S99QP0C3JDI8odHRUBD8J2KA!!/delta/base64xml/L3dJdyEvd0ZNQUFzQUMvNElVRS82XzFLX1NF?WCM_GLOBAL_CO NTEXT=/wps/wcm/connect/affinia.websites.content/Training/Learning+Center/raybestos/Some+Like+it+Hot

I do not know if they are economy or not .. I simply purchased what they had available. Is there supposed to be any play in the rotors or do they fit tight? I obviously have not had much experience with brakes other than replacing pads. Appreciate all responses.

The rotors are not affixed to the hub and can move around until the wheel is installed and the lugnuts are torqued.

What year Taurus did you install these on, and does it have ABS? How did you compress the calipers to fit the pads over the new rotor? Did you also install new pads?

It is recommended that you open the bleeder screw when compressing the calipers rather than forcing the old and possibly contaminated fluid back into the system, especially if you have ABS. Also, it is recommended to replace the brake pads when replacing the rotors.

You should probably take the brake calipers loose again and make sure the clean the slide bolts and re-lubricate them with synthetic brake grease. Also, inspect the brake hoses for any cracking or appearance of buldges. Maybe the brake hoses are starting to collapse and restrict the flow of brake fluid, preventing the calipers from releasing immediately when the brake pedal is released. Depending on the year of the Taurus and how long it's been since the brake hoses were last replaced and the brake system fluid flushed, I'd suggest replacing the brake hoses just for preventive maintenance anyway. Your safety, as well as the safety of others you share the roads with is worth the cost of new brake hoses and fresh fluid.

-Rod

These rotors were installed on a 2000 Taurus with 90000 miles. I have installed brake pads/shoes for years on many different vehicles but this is only the second vehicle in which I personally replaced front rotors .. Yes I replaced the pads when the rotors were installed. Compressed the piston to allow the pads room to mount. The "clunking" noise began only after installing the new rotors. The calipher seems to be holding tight against the rotor but I can grap hold of the rotor and get some sideways movement. I checked the other side and it is the same. I just cant remember if that was the case before I installed the new ones. The reason I installed new rotors was because I had noticed some warping .. could feel it in the pedal. This is the second set of rotors ( I had the other set of rotors installed by someone else) Thanks for the response.

The old rotors may not have had sideways movement before you replaced it because it was probably a bit corroded to the hub. I suspect you had to work it a bit to remove it from the car, it didn't just fall right off when you removed the caliper, right? Or, you may have a rotor hat chamfer issue such as RickMN suggested. That information is news to me, so I'm not sure how to suggest checking for that.

Also, there are spring dealies that should keep the pad centered. If those springs are not properly installed, one or more pads may be moving around causing the clunk.

You didn't address whether or not you removed, inspected, cleaned, and re-lubricated the locating (slide) pins. Were the old pads wearing evenly, or was the inside pad thinner than the outside pad? Also, make sure that all lugnuts were torqued. When the wheels are properly torqued, the rotor will not be able to move sideways.

When you compress the caliper pistons, I suggest you open the bleeder screw and let the fluid flow out the bleeder rather than forcing it back in to the system.

Also, since your car is ~7 years old now, I'd suggest you flush the brake system and install fresh fluid. Your Taurus certainly has ABS, and that ABS pump is expensive to replace. Old fluid is hygroscopic, meaning it will readily absorb moisture. That moisture can corrode the various valves in the ABS pump and cause it to fail. Obviously, you'll need to activate the ABS pump to get the new fluid to flush out the pump. That can be accomplished by using a scan tool that is able to activate the pump, or by taking the car out on a deserted gravel or sand road and getting the ABS to kick in a few times.

It used to be recommended that the brake fluid be renewed annually. With the synthetics that are being used in some newer cars, I'm not sure if that cycle has changed.

I guess I've deviated from the subject you posted about, so I'll go back to my hole.

-Rod

Your Taurus certainly has ABS, and that ABS pump is expensive to replace.

Not all 2000+ Taurus' have ABS. According to the local Ford dealer, only about half of 2000-2002 Taurus' have ABS.
It's just one less thing to go wrong with a car.

Did you spray down the new rotors down with brake clean?That is one cause also,there is protectant oil on the new rotors to prevent rusting.

Can't remember where I read it but the fluid in the ABS circulates around through the lines and reservior and ABS pump but with conventional brakes it does not circulate. That's why I siphoned the reservior dry then refilled with synthetic fluid. Drove it a few days then siphoned it dry and refilled. Did that maybe five times so hopefully I got most of the old fluid out. I dun'no, . . . what'cha think ? ? ? :dunno:

I cleaned the rotors thoroughly before they were installed .. removed the protective film .. did everything but change the fluid. This is something that is happening right after the rotors were installed. There were no clunking sounds with the old rotors. All of what you are saying may be helpful but there is something I have missed. Something that is not as it was before. I am more inclined to believe the rotors I purchased are just not fitting like the previous ones .. causing a bit of play and thus noise/clunking. I am going to seek another opinion and take them to a brake shop for inspection. Appreciate all the suggestions and input.

Can't remember where I read it but the fluid in the ABS circulates around through the lines and reservior and ABS pump but with conventional brakes it does not circulate.

I think that may be backward. If you don't have ABS, there is nothing that the fluid would not circulate through. Well, I guess circulate may not be the right there, but rather flow through.

Without ABS, the brake hydraulic system consists of the the master cylinder, proportioning valve, brake lines, brake hoses, brake calipers (and wheel cylinders if you have rear drum brakes). All of these components get used during a typical braking event and when the brake pedal is released when the system is functioning properly.

However, in an ABS system, you have all those same components plus an ABS pump. The ABS pump has fluid in it as well, but under a normal braking event the pump is not activated, so it does not circulate fluid. The only way the fluid in the ABS pump transfers from the pump to the braking system is when the ABS pump is activated.

-Rod

Looks like you're getting answers to questions you didn't ask!
I just did front rotors on a '99 SE, and it was about as smooth as it could have been. Here's my thoughts:
As much as you don't want to do it, take it apart again. Clean the area where the rotor and hub meet, to assure there's nothing keep your rotors from seating to the hub (rust, etc). Replace the rotor, and notice that they have insets where the hub bolts rest. In that position, they should sit nice and flat to the hub, but they won't be secured until the wheel and nuts go back on. With the Caliper bracket in place, lube up the piston/pad contact point with brake grease to eliminate chatter, then slide in the pads until they sit nice and snug. Open the bleeder and compress the piston, then slide the caliper in place. As one prior poster noted, make sure the caliper sliders are clean and lubed, too. When you put the road wheel back on, and tighten it up, it puts the rotor into a sandwich, between the hub and the road wheel... That's what stops the play. If I were a gambling man, I'd bet the clunk you're hearing is one of the pads out of position or sticking on a little rust or a rough spot, and not the rotor at all... just my guess, because if the rotor was out of alignment, you'd definitely feel it in the pedal.
Good Luck!

BTW- One thing I didn't notice mentioned is the pistons in the calipers. It is possible that they're sticking in the bore due to rust or a ridge. When you pushed them back in, you may have put them into an area where they're binding. If so, the pads will want to stick in or out, and will give you the clunk when they break free.
It's hard to tell, without taking the pistons out of the bores, and that's pretty much a last resort. Once they're out, it's best to rebuild/replace the calipers.