Brakes Brake Pads are too thick

Swhitney

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Feb 11, 2019
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Here's the parts list:
1992 Mustang Fox
8.8 inch rear end
LMR 11.65" rear rotors here
LMR caliper brackets for 11.65" rear calipers here
Stock length axles (87-93)
caliper brackets to clear the 11.65 inch rotor
stock rear calipers for 94-04

The caliper bracket fits great, the problem is the pads are too thick for the caliper to fit over the bracket. I went to the local auto parts store to compare the cobra and non cobra pads and they seem to be the same thickness. The part number for the pads are SC627A, thru O'Reillys auto parts, and the pads measure around 15.2 mm thick (each).

Photo May 01, 9 19 29 AM.jpg


Photo May 01, 9 19 24 AM.jpg

Photo May 01, 9 19 43 AM.jpg
 
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KRUISR

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Apr 16, 2015
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Is caliper piston pushed all the way back? Your pic above looks not fully retracted.

1619921241109.png

See how flat top of piston is flush with top edge of seal.

Could be rotor thickness that the stock calipers work with (0.545" solid vs 0.71" vented).

Also, when I was looking up some pad thicknesses to help out I noticed there are 16.9mm thick pads and 14.4mm pads. I could not get a definitive answer as to stock vs Cobra for either. Sorry. Check the pads you have, if 16.9mm, maybe you can source some 14.4s.
 

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Mustang5L5

i'm familiar with penetration
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Cobra pads are supposed to be thinner than the GT/V6 pads to allow for clearance with the vented 11.65” rotor. I don’t know the numbers, but there is a difference.

Sounds like you might have the thicker pads, rather than the thinner set you need. I fortunately, this happens from time to time with parts store pads.
 
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Swhitney

Member
Feb 11, 2019
90
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Oregon City
Cobra pads are supposed to be thinner than the GT/V6 pads to allow for clearance with the vented 11.65” rotor. I don’t know the numbers, but there is a difference.

Sounds like you might have the thicker pads, rather than the thinner set you need. I fortunately, this happens from time to time with parts store pads.
I’ve twisted in the brake caliper as far as she’ll go. Also, if possible can someone share a part number for those rear cobra pads? I would also like to know the thickness of the GT and Cobra style.
 

Mustang5L5

i'm familiar with penetration
Mod Dude
Feb 18, 2001
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Approx 15mm for Cobra and approx 17mm for GT

OEM part number for cobra pads is

1U2Z-2V200-JA​

Motorcraft BR72B
 

Swhitney

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Feb 11, 2019
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Approx 15mm for Cobra and approx 17mm for GT

OEM part number for cobra pads is

1U2Z-2V200-JA​

Motorcraft BR72B
Damn! Mine are 15 mm thick, just measured. Then my caliper isn’t going in anymore. Maybe I need to swap them out. The calipers never changed between got and cobra, correct?
 

Mustang5L5

i'm familiar with penetration
Mod Dude
Feb 18, 2001
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Calipers are the same. Only the pad abutment is different but it won’t matter for your purposes.

you sure the piston is screwed in all the way? From the shot above, it does look to be protruding slightly.
 

Swhitney

Member
Feb 11, 2019
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Calipers are the same. Only the pad abutment is different but it won’t matter for your purposes.

you sure the piston is screwed in all the way? From the shot above, it does look to be protruding slightly.
I spun that thing serval times, and it didn’t in any further. Should I replace them?
 

Mustang5L5

i'm familiar with penetration
Mod Dude
Feb 18, 2001
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I doubt both calipers would have this issue. Do you have a pic of them from the side showing the piston so we can take a look?

The rotor should be approx 0.72" (18mm) thick.

Nothing in your pics looks wrong (i have these same brakes), but the pic of the caliper does look like the piston protrudes out a tad too much. Just need a better pic to confirm.

You could always pick up a single parts store caliper to test fit and then return, but before you go out of your way lets see a pic of the piston like Kruisr showed in post #2
 

Swhitney

Member
Feb 11, 2019
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Oregon City
I doubt both calipers would have this issue. Do you have a pic of them from the side showing the piston so we can take a look?

The rotor should be approx 0.72" (18mm) thick.

Nothing in your pics looks wrong (i have these same brakes), but the pic of the caliper does look like the piston protrudes out a tad too much. Just need a better pic to confirm.

You could always pick up a single parts store caliper to test fit and then return, but before you go out of your way lets see a pic of the piston like Kruisr showed in post #2
I resolved just the caliper and it solved the problem for the passenger side.

next problem is how close the caliper bracket is to the rotor. What are your thoughts?
 

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Swhitney

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I resolved just the caliper and it solved the problem for the passenger side.

next problem is how close the caliper bracket is to the rotor. What are your thoughts?
The driver side is even worse! It’s like it needs a 3mm spacer on both sides.
 

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Mustang5L5

i'm familiar with penetration
Mod Dude
Feb 18, 2001
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These are offset brackets? If so, they usually include a washer that is used as a spacer. The drivers side looks like it needs one, but pass side looks ok from the pic
 

Swhitney

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Feb 11, 2019
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These are offset brackets? If so, they usually include a washer that is used as a spacer. The drivers side looks like it needs one, but pass side looks ok from the pic
These are bracket I got from LMR. According to their install video the washer go directly on the bolt. I can get some 18mm bolts from the hardware store tomorrow to try and space them out. Thoughts?

 

Mustang5L5

i'm familiar with penetration
Mod Dude
Feb 18, 2001
35,961
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Usually the washers are installed between the pad abutment and the axle flange bracket as a way of centering the caliper over the rotor. This is standard practice in a number of aftermarket brake kits such as Baer. You may not need much to center that, and you don't need to be perfect. Just need to ensure adequate space on each side to account for rotor wobble.
 

Swhitney

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Feb 11, 2019
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Oregon City
Usually the washers are installed between the pad abutment and the axle flange bracket as a way of centering the caliper over the rotor. This is standard practice in a number of aftermarket brake kits such as Baer. You may not need much to center that, and you don't need to be perfect. Just need to ensure adequate space on each side to account for rotor wobble.
Thanks for your help, you’ve been a huge help. Had to order some SS brake lines as the banjo bolt was locked in my current rubber brake line.

this rear brake job has been a huge pain in my butt.
 

limp

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Thanks for your help, you’ve been a huge help. Had to order some SS brake lines as the banjo bolt was locked in my current rubber brake line.

this rear brake job has been a huge pain in my butt.
All good things don't come easy... Plato ( not really)