I have a 91 Civic Si, and am attempting to do my front brakes for the first time. The problem is that all my local parts stores don't seem to list any different rotor or pad specifications between the Si model and lower models like the EX or DX. One store (the first store i went to) told me that the rotors between the Si and other models were in fact different but they did not have any in stock, which really has me confused since all the other store's computer systems didn't list the Si model at all.

Are there any differences in the rotors for my 91 Si vs rotors for a ex or dx???

 

i could be wrong but i didnt think the brake setup was any different at all for any model civic from 88-91

 

There are difference in the rotors. HF have very smaller rotors where are EX have the largest rotors. So the rotors can be different and you need to make sure you are getting the correct ones.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ballersize &raquo;</TD></TR><TR><TD CLASS="quote">i could be wrong but i didnt think the brake setup was any different at all for any model civic from 88-91</TD></TR></TABLE>

Ever heard of the 90-91 Civic EX Sedan? That had the bigger 10.2" brakes up front. Also, I am not sure but the STD might be a little different as far as the Civic goes but don't quote me on that.

 

Well since none of the part stores seem to know the difference, i was hoping someone on here would.

I did buy some rotors for a "1991 Civic" no model listed just to compare to my current rotors. They were supre cheap and my thoughts were just to return them if they were not the right ones. My current rotors are about .725" and the new ones i bought are .830" which seems to be too big, prpobably for a Ex. I guess i'll keep searching...

 

I can't believe with all the gurus on this site no one knows the real differences between the brakes of EF models.

From what i've dug up, the Si uses a rotor that is .750" thick while all other 2WD EF Civics use a rotor that is .830" thick, with all rotors sharing the same outside diameter. Seems strange that the Si (sporty/heavier model) would use a thinner rotor but thats the info i've found.

I have also found that the thinner .750" Si rotors cost roughly 4X as much as the .830" rotors ($15 vs $65) which makes me wonder if the .830" rotors will fit my Si. Does anyone know is the Si has a smaller caliper spacing for the thinner rotors as well or it they are all the same between different EF models??? I would love to me able to use the much cheaper and thicker .830" rotors on my car.

Any info would help!

 

Well since finding the correct rotors for my car has been impossible for the last week i decided to try the incorrect rotors instead. I picked up a pair of the .830" thick rotors and installed them, the right side fit just fine but the left side was a little tight to i had to lightly sand the pads to make it fit. Everything fits and works just fine with the .830" rotors except i'm still having the same weird problem with the new brakes that i am with the old ones.

The problem is, the pads and rotors are wearing down more along the outter edge of the rotors and pads than they are than they are closer to the hub. This was the whole reason a bought new brake parts in the first place and now is doing it again and i have no clue why. My old rotors were actually measuring about .02-.03" difference between the outter more contact point od the pad and the inner most. My original thought was that the the guide pins were frozen and the calipers were not sliding correctly but when i first pulled everything apart they seemed to slide just fine. So i pulled the calipers apart anyway, cleaned and regreased everything when i installed the new pads and rotors and i am still getting the uneven wear on the pads and rotors, both sides of the both sides of the car. After a couple test drives i can see the rotors were only touched by the pads the outter 2/3 of where they should be having full contact.

Does anyone have a clue why my brakes are wearing like this?