brake help

jwinkler · #1 (**permalink**) 03-08-2003, 02:31 PM

Another question for Don and DV - in the process of replacing my springs, I saw that I've got a massive groove cut in one of my rotors. Got the Hanes '78 Mustang manual, got the rotor off (still have a question about the caliper/mounting plate assembly, but that's for another day), and figured it was as simple as a trip to Autozone for another MII rotor.

Guess again - the MII had 4 lug rotors, and Autozone doesn't stock a 5 lug version. Is there another part number for a 5 lug rotor that will fit the MII spindle and caliper?

Thanks,

JLW

dscott · #2 (**permalink**) 03-09-2003, 10:34 AM

JLW, I don't know of a stock application for the rotor. They are available through many dealers of aftermarket parts. Look for any street rod shops in your area and they should be able to get them. If not then I or DV can order one for you. If you pick up a street rodder magazine there's probably 25 places to buy them from.
Don

cobra427mnsi · #3 (**permalink**) 03-11-2003, 06:56 AM

jwinkler

Are you sure that you have MII rotors? Did you build the car yourself or did you buy it already built? The reason I ask is your questioning of the caliper plate assembly. By what you are saying, it sounds like you have the 11" Granada rotor conversion that is so popular. The Granada rotors have 5 lugs. This conversion can also include Camaro rotors if you use a special caliper plate attachment assembly.

Just my .02 from the info that you gave.

Paul

jwinkler · #4 (**permalink**) 03-11-2003, 10:23 PM

I was wondering if they might be Granada rotors - I noticed a number on the back of the rotor that looked "Ford"-ish - D-902.903.

However, when I measured the rotor, it didn't even measure 10" in diameter. Per the Haynes manual, the caliper and mounting bracket look like standard MII pieces. I guess I could try the Granada rotor and see if it rubs. Would Granada calipers mount to the bracket? Or at this point, would it be better just to get a kit from ECI or someone else?

Oddly enough, when I called Summit, I stumped the sales guy when I asked for 5 lug MII rotors. I figured he'd have gotten that request tons of times from rodders like Don mentioned, but he didn't have a clue.

Thanks for the input,

JLW

jwinkler · #5 (**permalink**) 04-12-2003, 09:19 AM

Thanks (once again) to Don Scott, I got the right 5-lug rotors, and have just now gotten the new rotors back on.

I was thinking I was in the home stretch, with only the pads and calipers to put back on. However, when I put the inside pad in the caliper bracket, it looks like there's nothing to pull it off the rotor after the caliper releases. Am I missing something? After the caliper piston pushes the inside pad against the disc, what pulls it back?

Thanks,

JLW
(still on jackstands

)

petek · #6 (**permalink**) 04-12-2003, 02:01 PM

JLW,

The caliper floats, the one end of the piston pushes one pad in, the other end of the piston pushes against the caliper, the caliper "pulls" the other pad in.

jwinkler · #7 (**permalink**) 04-12-2003, 02:59 PM

Petek -

Thanks for the reply.

I get how the pads are pushed onto the disc, but what I don't see is how the inner pad is pulled off the pad when the brakes are released.

JLW
(ever-mystified by the magic that is automotive engineering)

petek · #8 (**permalink**) 04-12-2003, 09:59 PM

The same way the one with the piston moves away from the pad. Remember, the pads don't have to move much, just enough to let the rotor spin freely.

Whaler · #9 (**permalink**) 04-12-2003, 10:35 PM

Hi JLW

Man I have gone over my brakes so much in the last 6 months I could draw them and put them together in my sleep....lol

The whole caliper assy is really mounted with 2 bolts that go thru a set of "slides" from the back side. The assy. is meant to float and slide in a self centering manner, following the centerline of the rotor. Don't forget these pads push against each other while the pressure is on, to clamp the disc rotor. After the pressure is off the pedal they should have a slight feel of "just clearing the face" on each side. New brakes and assemblies will also need to seat. It's also a good idea to rebleed brakes after a few runs and seating.

Mine at the moment aren't as high or as hard on the first stab of the pedal. They are good enough ( safe) though to get me to that next bleed which is soon after seating the brakes and getting a bit of braking heat on them.

FYI There is a SLIGHT drag on the pads to the rotor. The pads should not ever "retract" and give you a major gap.....because if so, guess what is required to bring the pads back into a quick rotor contact... Yep ....you pumping the hell out of your brakes when you least expected to.

Tim

jwinkler · #10 (**permalink**) 04-13-2003, 10:07 AM

Thanks again for the replies.

So if I'm understanding right, when the caliper piston releases, the outer pad moves away because it's attached to the caliper (or is it that the rotor is no longer pushed into the outer pad?). The inner pad that is mounted on the caliper bracket is *NOT* pulled away from the rotor, but its contact with the rotor is not a problem since there's no pressure forcing the contact.

Thanks again, and here's hoping!

JLW
(out to the garage)