Rob W.

iTrader: (8)

I just got my shiny new silver EVO Monday night. What a fabulous car! I'm extremely happy, other than the 2 times the gearbox has ground on the 1->2 shift even though the clutch was all the way depressed. (WTF?! I thought all the complaints I read on here were just people abusing their cars, but now I know different!)

Anyway, I wanted to ask some questions about the break-in period. I know there's about 100 opinions on the engine side of things, so I won't get into that. What I want to know is regarding the brakes. The dealer was very, very firm that the brakes need to be babied for the first 500 miles. He was not at all concerned about the rest of the car ('those engines are basically pre-broken in anyway, so don't worry about that, just be careful with the brakes!').

My experience on my Z with high performance street pads (Porterfield R4-S, Axxis Metal Matrix, etc.) and racing pads (Porterfield R4, Hawk Blue) has always been that you are supposed to 'bed' the pads in. Basically, you get them smoking hot (literally) by doing a series of ~75->0mph stops, then drive them to cool off, and finally park it for 24 hours. This is obviously VERY different from what the Mitsu dealer is recommending.

I've been pretty much babying them (as well as the engine, actually). I'm afraid that if I break them in wrong, they'll be squeaking all the time (as some people here have complained about already).

I have 250 miles on it now, and I can feel that the brakes have finally begun to settle in a bit (less rumbling when pressed, more grab), though I still haven't done a single hard stop to really check them out.

Any comments, advice, or opinions on this subject would be appreciated.

Thanks,

Rob W.

Scottybob

iTrader: (3)

Babying new brakes will almost guarantee squeeling. You should get the new pads hot enough so that you can smell them, but not so hot that smoke is boiling out from the wheel wells. You dont need to get a stock pad as hot as a full race pad, but getting them hot enough to burn off the stuff that is used in the manufacturing of the pads will help a lot.

MAKE SURE THE BRAKES HAVE COOLED OFF BEFORE YOU STOP THE CAR. The reason that they tell you to baby the brakes in the first 500 miles is parking the car with hot brakes allows all that stuff you are burning off with the break in process to continue to cook off resulting in a deposit on the rotors. These deposits will often cause a brake shimmy, usually diagnosed as "warped rotors" If you think about all this you will see how the average mechanic would come to the conclusion that hard use of brakes during break in causes warped rotors. BTW, this is also why you dont want to use your parking brake after a track session.

A sure way to know if a pad is bedded in is to look at the edge where the pad contacts the rotor it should have about a 1/8" where the pad material is discolored. In most cases it will be white to light greyish depening on the pad material.

Hope this helps. I've probably done the process on a hundred sets of pads over the years and have never had a squeeling problem on any of them.

Dale_K

iTrader: (1)

Go to the NHTSA web site and search for TSB's. The Mitsubishi bulletin basically says to baby the brakes and gives service techs instructions about shimming the pads.

BTW, I also picked up a new EVO this week. I noticed that the brakes didn't bite very hard at first. When I looked at the disks I could see areas where the contact wasn't consistent. It is getting better but this is the first car I've owned that needed this much brake break-in. I've never had Brembos before but I've had 2 new Corvettes and their brakes were perfect from the very beginning.