PDA

View Full Version : rotors?


BadMoFo
11-07-2004, 09:09 PM
ok I have had my brake pads and rotors resurfaced about 5 or 6 months ago but for some reason the passenger side rear brake or rotor keeps squeeking, it is a constant squeek, squeek, squeek when I drive and then a long squeeeeeek when I apply the brakes. I was wondering if I needed to replace the rotors or something? I know when I took them into to have them done (three times at a crappy dealership) the third time they said one of the back rotors was kinda warped but they fixed it. also what sizes are my rotors front and back and what would be a good replacement for a decent price. I dont want to break the piggy bank on this one, heck I would even buy stock rotors new if I had to, I am just tired of this damn squeek.

tazzracing1
11-07-2004, 09:24 PM
Rotors are actually hard to make sure they are trued and balanced it is a good idea to replace them when change pads if the wear is not even(groves) if they are still smooth the glazing can be removed by hand sanding in a circle motion. Rotors are generally need to be replaced if they are warped usually not much hope in truing the rotors and most of the time they jst warp right away. I hope this helps a little bit.

sssvtcobra
11-07-2004, 10:21 PM
BadMoFo,

I replaced my rotors with stock size replacements from discbrakesrus.com. They are cross drilled and slotted. I don't ever see the track, just fun spirited driving. I can't remember what I paid for them since I also bought calipers from them as well. I think that is how it is spelled out. If not it might be discbrakes-r-us.com.

Hope this helps
Jeff

johnbasf
11-07-2004, 11:09 PM
Tire Rack has the '99 and up replacement rotors for a good price. You may need to put lube on the back of the pads. http://www.tirerack.com/brakes/results.jsp?scat=Rotors&autoMake=Ford&autoModel=Mustang+Cobra&autoModClar=&autoYear=1999&brand=Brembo&perfcat=premium&x=102&y=6

BadMoFo
11-08-2004, 10:03 AM
ok got one from the tirerack. what kind of lube do I need to add and where can I buy it? thanks.

johnbasf
11-08-2004, 10:29 AM
Give a parts house a call.

BigRedMachine
11-08-2004, 11:14 AM
BadMoFo,

I'm having pretty much the same delimma with my rotors and pads. Squeak, squeak, squeak every time I press the pedal :mad: It's very irritating. At the end of the month I'll have enough cash to replace the pads and resurface the rotors. Hopefully that will help. I'm running Prostop slotted rotors with Hawks-Racing pads.

SNAKEYE
11-08-2004, 03:22 PM
ok I have had my brake pads and rotors resurfaced about 5 or 6 months ago but for some reason the passenger side rear brake or rotor keeps squeeking, it is a constant squeek, squeek, squeek when I drive and then a long squeeeeeek when I apply the brakes. I was wondering if I needed to replace the rotors or something? I know when I took them into to have them done (three times at a crappy dealership) the third time they said one of the back rotors was kinda warped but they fixed it. also what sizes are my rotors front and back and what would be a good replacement for a decent price. I dont want to break the piggy bank on this one, heck I would even buy stock rotors new if I had to, I am just tired of this damn squeek.
I don't think you did yourself any favor by having the rotors resurfaced. Turning down rotors is not the way to go, even if they technically have enough meat left to do the job afterward, they loose their ability to deal with the heat generated (less mass, less able to absorb and release the heat properly) and quickly wind up warping and sending you back for another brake job. If you plan to keep the car - replace the rotors when you replace the pads.

I wouldn't leave anybody do 'crappy' work on my car more than one time! 'Crappy' work begets 'crappy' work. Go somewhere else, and it doesn't have to be a dealership.

Your current passenger-side rear brake problem is probably due to a brake piston that is not retracting after release of the brake pedal, or a caliper that is hanging up and not allowiing the pad to clear the rotor. Either way, the pad is constantly dragging on the rotor (the 'constant squeek, squeek, squeek' you are reporting), thus wearing out the pad and/or rotor prematurely (the 'long squeeeeek' you are reporting). Don't wait for this squeaking to turn into a chatter and/or shutter! You may be headed toward a disaster!

Besides squeaks from wornout pads and rotors, there are other squeaks from pads and rotors that are perfectly servicable, albeit annoying. Materials used in the pads can cause squeaks. Pad construction features can cause or alleviate squeeks. Pad installation features can cause squeeks and rattles. Those beveled leading and trailing edges on the pad surface and the self-adhesive backing material all serve a purpose.

Personally I have not yet, at 44K miles, had to replace any brake components on my Cobra. I don't do any kind of racing, so the wear of the stock pads and rotors has been just fine. However, the pads are all due for replacement. I am going to do the brake work myself during this Winter's storage period. I just replaced front pads on my minivan with the top-of-the-line pad from Auto Zone. Supposedly low dust, carbon fibre something or other, lifetime warranty. These pads amazed me! Never have I changed pads and had such a noticable improvement in braking performance. For my purposes, the AZ pads will be just fine on the Cobra too.

THINK SPRING!

BadMoFo
11-08-2004, 03:58 PM
ok so if the brake piston isnt retracting how would I fix that if when I replace the rotors that doesnt help? cause like i said the pads are new on all four corners.

Abneriel
11-08-2004, 05:06 PM
ok so if the brake piston isnt retracting how would I fix that if when I replace the rotors that doesnt help? cause like i said the pads are new on all four corners.

the rear brake caliper pistons need to be rotated with a special tool while being reinstalled after a pad change. If they messed this up you may have to replace the calipers. Taking them off and installing new ones is not hard at all.

I had the exact same problem after getting work done at a dealership...only problem is it was a dodge dealership and I had a friend do it...if you can I'd go back and see if the piston is screwy. If so, they should replace it since they're the one's who messed up.

Have you noticed a decrease in braking ability since getting the work done?

johnbasf
11-08-2004, 07:08 PM
ok so if the brake piston isnt retracting how would I fix that if when I replace the rotors that doesnt help? cause like i said the pads are new on all four corners.

How far are you from Winston-Salem? I could help you with this.

johnbasf
11-08-2004, 07:09 PM
[QUOTE=BigRedMachine]BadMoFo,

I'm having pretty much the same delimma with my rotors and pads. Squeak, squeak, squeak every time I press the pedal :mad: It's very irritating. At the end of the month I'll have enough cash to replace the pads and resurface the rotors. Hopefully that will help. I'm running Prostop slotted rotors with Hawks-Racing pads.[/QUOTE

Hawk racing pads are not good to use on the street. :thumbsup:

SNAKEYE
11-09-2004, 10:24 AM
ok so if the brake piston isnt retracting how would I fix that if when I replace the rotors that doesnt help? cause like i said the pads are new on all four corners.
Like Abnerial says, the rear brake pistons rotate. It's part of the emergency brake design. They rotate outward and stay extended as the pads wear. In order to have replaced the pads the installer needs a special tool to be able to rotate the piston back into the bore to create enough space between the piston/caliper frame and the rotor. It would have been impossible to install new (thick) pads without putting the piston back into the bore. If you do a rear brake job yourself, the special tool is available from Auto Zone for free. You have to put down the purchase price of the tool, but you get all of the money back when you return the tool. Something for nothing. And the best part is the tool makes the job real easy.
A brake piston can freeze or be kept from retracting adequately by dirt or rust. If the rubber boot is cracked dirt and water can enter. Water can also be present in the brake fluid and cause rusting from within. Prolong periods of non-use aid in the rusting process by not having the parts moving on each other and kind of cleaning themselves. Also, if the caliper frame cannot slide on its pins from dirt, it will hold the pads to the rotor. These types of things causes excessive, premature wear on the pads. And before you know it the wornout pad is tearing up the rotor.
To fix the dirty pins, remove them and flush their holes and boots clean with brake cleaner. This should have been done at pad replacement.
As for fixing the piston, I've been successful (with front calipers) with squirting WD40 into the chamber created between the rubber boot and the piston by carefully pulling the rubber boot's edge out of the groove in the piston and inserting the tip of the WD40's spray nozzle. Just a short blast of WD40. No need to fill the space with anymore WD40 than what will free things up. Too much may come back out later and get spread around on the rotor by air flowing around the wheel.
Other than that, it's new caliper time. If you have to do that, also flush and refill the entire braking system with new fluid to remove contaminants and water from the system.

BigRedMachine
11-09-2004, 10:36 AM
[QUOTE=BigRedMachine]BadMoFo,

Hawk racing pads are not good to use on the street. :thumbsup:
Yea, I know, but the guy at the speed shop sold me on them and they perform quite well, they're just very noisy

GUMBALL
11-09-2004, 10:42 AM
johnbasf:
Which Hawk pads are you using?...
I have Hawk blue on the front, and Hawk black on the rear of mine. I do both street and track (club events) and they are a very good compromise.
A more agressive pad might not work as well.

As for the squeek, sometimes it is caused by the pad backing plate rubbing against the caliper pistons. Try a product called "brakequiet" from an auto supply store (Napa, Autozone, etc). If you can't find that, apply a thin coat of copperlube to the pad backing plate.

BigRedMachine
11-09-2004, 01:12 PM
I might try a softer pad than the Hawks pads I have on there now (I think it's the middle performer, not the street pads, but not the racing compound either, street/track combo pads maybe? can't remember).

I've tried a product from autozone that sprayed onto the back of the backing plate and it was quiet for about 2 days and started sqeaking again. Like I said, I don't have a problem with the performance, just the noise can get on your nerves after a while.

I'll try the copperlube next before I buy another set of pads and see if that will work. :)

johnbasf
11-09-2004, 01:42 PM
johnbasf:
Which Hawk pads are you using?...
I have Hawk blue on the front, and Hawk black on the rear of mine. I do both street and track (club events) and they are a very good compromise.
A more agressive pad might not work as well.

As for the squeek, sometimes it is caused by the pad backing plate rubbing against the caliper pistons. Try a product called "brakequiet" from an auto supply store (Napa, Autozone, etc). If you can't find that, apply a thin coat of copperlube to the pad backing plate.

When my car was streetable I used the blues. They were very hard on rotors on the street. The "brakequite" work good for the squeak.

BadMoFo
11-09-2004, 03:04 PM
no decrease in performance, and the pads on mine are ford pads. I guess when the rotor shows up I will look at the caliper and hope that it can be fixed if it is broken.

BadMoFo
11-12-2004, 02:06 PM
How far are you from Winston-Salem? I could help you with this.

hey thanks for the offer, but just to let you know I am about a 5 hour drive from there at least.