Contour Enthusiasts Group Archives Forums Modifications Brakes Mintex 1144 pads

I recently purchased a set of KVR gas slotted rotors and Mintex 144 C-tech pads for all four corners. Now, I have problems with squeaking. It is a very sharp squeak that can be heard very clearly from inside the car with the radio at about half volume. Has anyone else had a similar problem? I thought that this would go away after the pads got broken in, but it has been almost a month since I did this. Thoughts?

There are several things to think about here.

High performance pads by nature tend to be noisier than normal duty pads, mainly because they are harder.

Improper installation can agrivate noise. If for some reason the pads did not quite get mounted properly in the calipers it can contribute to noise. You may think that there is no way to get them in wrong, but you would be surprised at how Murphy's law applies here. Proper lubrication is critical. The caliper slide pins must be properly lubricated and able to move freely. Every part of the pad backing plate that touches the caliper must be lubricated, even any shims that might be there. High performance pads usually include shims than can help cut down on noise. If they did not come with shims, you may want to add some. They go between the backing plate of the pad and the caliper. I think that Raybestos makes a universal shim that can be cut to fit. There are gel type anti squeel products that can be used instead of grease on the back of the backing plate only that sometimes helps. Don't let the gel get near surfaces that need to slide though.

The reason for the lubrication is two fold. First so that the pad properly slides and retracts as the brakes are applied and released. Second to dampen vibration as the pad "chatters" from the torque applied by the spinning rotor.

A little bit of the same type of lubrication damping can also be applied to where the hub meets the rotor and where the wheel meets the rotor. Grease will not do the job though. In this area, apply a bit of anti-sieze compound.

Often it is helpful to bevel or champher the edges of the pad where it touches the rotor. Some high performance pads are beveled so much that the actual surface area of a new pad is nearly half of what it is when the pad is nearly worn out. You may not need nearly as much as this, but don't be afraid of filing or grinding a bit of bevel into the pad if needed. Roughly a 45 degree angle about 1/4" into the edge of the pad would be agressive.

Sometimes squeel noise is caused by the friction face of the pads and rotors glazing up. The glaze is much harder than the rest of the pad and can result in a noise that is a little like fingernails on a blackboard. The glaze comes from the pad material. Resin is used as a binding material to hold the various different materials together. Some resin comes to the surface as the other materials are ground away and some of it transfers to the rotor. The resulting hard glass like coating is more prone to squeeling.

Usually the drivers that have the most problem with brake squeel are those that either are very mild brakers or those that are very agressive brakers. With a mild breaker, the glaze never has a chance to burn off. With a hard braker, the glaze builds up faster than it can burn off. A car that is driven by a mild braker can sometimes be cured of squeel with a few hard stops. Elizabeth's 130 MPH then slam on the brakes to clean the brakes is more than a bit extreme though.

Sorry about the "brain dump", but I hope some of this may help.

FWIW: Recent brake job with new Mintex-AF rears and Performance Friction pads up front had both sets with beveled edges. Break in seemed longer than usual, but they are quiet and firm now.

Mintex pads take A LONG time to break in, almost 3K miles on a set I had in the rear. The squealed horribly all the time, I hated it, and bought a set from Stazi(the titanium ones) to replace 'em. . .of course, I was lazy, and never got around to it, and remarkably, the squeaking and squealing and the nastiness is gone.

I have mintex in the rear and stazi's bendix up front, I still like the Mintex better for dusting, there is none whereas even stazis seems similar to stock being a little better, but its a huge difference in dusting.

I had no squealing or break in issues with either pad.

Kinger,

Did you ever run the Mintex pads up front? You can't really compare different pads if you're running one set up front and different set in the rear as the rear brakes don't contribute a whole lot to braking. I still have stock pads in the rear and they hardly dust at all. I put Mintex pads up front and they dust about half as much as the stock pads up front.

Nope never had them in front, only the rears. I guess I never thought about the dusting being different front to rear...makes sense though.

Funny, I have the mintex all around and they dust like crazy! Stop nice though.

Jim