Napsterfreak15

I just replace my rear rotors with some brembos because i had them laying around. Now when i brake i hear a nastly grinding noise. i looked at the one making the noise and i see there are all these grooves in rotor?

Why is it doing this? my old rotor wasnt like this..

I'm using the same pads.

here is a pic of it

jjcobm

iTrader: (18)

How is the life on the brake pads? Is your brake caliper stuck on that side? Does the noise happen when you let off the brake or only when you brake? Did you disconnect the caliper brake line when servicing?

Napsterfreak15

outside Pad (pad that doing the damamge) has about 40% life left.

Inner pad is brand new. (the rotor wouldnt fit with the new pad witch is why i used the old one.

The loud grinding noise only happens when i actually brake

I didnt disconnect any lines but i did unscrew the bleeder a little bit and lost a few drops thats it though

I just put the rotors on yesterday..

jjcobm

iTrader: (18)

First off, new brake pads have to fit the rotors regardless, something is wrong here. Did you fully turn the caliper piston all the way in? I would make sure that caliper piston isn't seized and try to turn it in, if it doesn't go all the way into the caliper it is probably bad. Inspect the rubber boot.

If it goes in smoothly, I would try to extend the piston and make sure you don't have a lot of resistance when turning it the other way. I have a feeling you have a stuck caliper or air is in the line or just that brake pad is bad and grinding your rotor.

Bleed the brake caliper (you might of let air in when you "lost a few drops") after you do all this and find nothing wrong with it, but like i said those pads should fit in there no problem with that rotor when you retract the piston all the way, make sure the two indents on the pads like up with the caliper piston when you install them, you will know what I am talking about when you look at it.

Replace that brake pad, could possibly be that old one is bad and grinding up your rotor too, like I said both of the new ones need to fit in there.

Napsterfreak15

not only was the caliper piston not turned the right way i also did something else wrong and I'm a bit embarrassed to say it but my pad was on backwards.

so anyway yeah the rotor wont fit with my new Hawk HPS pads

jjcobm

iTrader: (18)

Thats odd that new brake pads will not fit. Are you sure they are for your brake system (vented rear brakes) as opposed to non-vented? Did you make sure to turn the piston all the way into the caliper and line up the two notches from the pads with the caliper piston?

You do have the parking brake off right?

By the way in those pictures the caliper piston isn't retracted all the way into the caliper, it should be flush with the caliper, if not more than flush it should be inside the caliper somewhat.

clokker

iTrader: (2)

Not only does the piston have to be screwed in- which retracts it- but there is also a dimple on the piston and a corresponding recess in the pad's back face...make sure those are aligned.
Otherwise the pad will not sit flush.

Napsterfreak15

Thanks for the info. As you can see there isn't even a pad on the piston and it STILL wont fit. (piston it not in the way either)

I bought i very large amount of parts and an fc shell from a kid and the pads came with it all.

Pad Specs:

HB158 HPS
Hawk-7266-2-FE
110-1AC29B

jjcobm

iTrader: (18)

OK, it looks like the slider pins (the top and bottom bolts that go throught the caliper into the mounting bracker) are not doing their job and need to be greased. The caliper slides on these two pins side to side as the piston pushes on the pads, at the moment the caliper is pushed towards the inside of the car, you need to slide the whole thing back to the outside . You need to undo those bolts and grease them with multi purpose grease, after this the caliper will slide freely. I bet if you wigle the caliper left to right it will start to move and this will center the caliper onto the rotor.

While you are doing this, its a good idea to lightly grease the top and bottom of the caliper where the tops and bottom of the brake pad go into (not the actual pad itself, but where the top edge sits on the caliper), this way they slide freely as you brake (same concept as the slider pins/bolts). Do this for both sides of the caliper (left and right brake pad).

By the way, thats what the rubber boots that go through the bolts are for, to protect dirt from getting into the grease.

Hazard15301

iTrader: (5)

There are two kinds of calipers for the 86-88 RX7s. Vented and non-vented. The vented rotor calipers are wider than the non. You must have the right rotor for your caliper. Vented rotors are thicker than non vented. So if you have the wide caliper, a vented rotor, and new pads (specifically for vented rotors) it WILL fit. That is assuming the piston is all the way back into the bore. If something doesn't fit, something is wrong.

Napsterfreak15

I'll try doing that. Those caliper slides might also be the reason my brakes stick when i rip the ebrake.

You are very smart with rx7s. Thanks again.