My Dad has a 97 Maxima and his brakes started squealing when he would come to a stop. They are fairly new so he took them to a mechanic and was told the following. The brakes sometimes overheat and "crystalize." This makes the brakes squeal. Also in regard to the e-brake. He was told something about using the e-brake adjusts the balance of the brakes so it it more towards the rear brakes which puts less stress on the front? I can understand the first thing he said but that second sounds pretty weird. If the brakes do crystalize, wouldn't using them wear the crystals off and they would stop squealing? Anyone know if these are true? Thanks.

 

Sometimes, heat and contaminants cause an effect called glazing on the pads.. I'm not sure what that means or what it even looks like --

I read that slotted rotors -- not cross drilled -- continuously deglaze brake pads -- which I suppose means scrubbing off contaminants --

Brake dust and other foreign matter is what causes the squealing sound -- Also, the rotors might be grooved or scored from contaminants caught in the pads -- might need a resurfacing --


I have no clue what that line about the emergency brake is about -- Is he telling your dad to pull the e-brake every time he stops -- That's kinda crazy but I guess that will change the braking balance..

 

The crystalizing he is referring to is more accurately called brake glazing. It is a normal thing to happen and doesn't affect braking performance very much. It does make the brakes squeal though, but I've learned to live with it.

As for the e-brake, setting the brake when you park actually adjusts the rear brakes. Well, I dunno if it really does, since that applied to drum brakes, and most disc brakes are self adjusting anyways. Either way, it does not mean you should pull your e-brake while the vehicle is in motion (unless you want to spin the car).

 

I could be wrong, but reversing readjusts disc brakes. Using the PARKING brake while driving with functional brakes is extremely dangerous. If pulled too far, the rear wheels will lock, causing loss of control of the car. If your brakes are at all functioning, never use the parking brake.

 

Glazing is not a good thing... It decrease the friction between the pad and rotor and lowers effective braking...

Both slotting and crossdrilling removes glazing by cutting thru the glazing with their following edges respectively. I think glazing is caused by overheating the pads so they 'crystalize' the top layer of the brake pads...

Using the parking brakes obviously biases the braking system towards the back... Not a very practical way of doing this... plus it's dangerous on corners. But this is how you can induce rear skids...

 

Just thought of something really dumb:

The title of this thread should have been "Brake fact vs. FRICTION" instead of FICTION, that would have been a silly pun.

 

hehe Didn't even think about that!

 

This was true for many models of drum brakes, but is not true for disk brakes.