2015 IRS Brake Installation Frustration

[bkhicks66]

I worked this weekend to get my coupe IRS with Knuckle and hubs all ready for IRS Brake installation. Went well after I discovered the flange spreader techniques of using threaded rod and 2 nuts.

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during my research for the IRS Brake Instalation I discovered I need to cut of one of the caliper Ears.
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I had a machine shop make the first cut on the Knuckles prior to instalation because I do not have a sawzall and now, I definitely do not want to disassemble anything.

Any suggestions on an easy way to do this. Will a hacksaw with a special Blade be an option and will that take 6 hours of cutting?

Anyone attempted this.

Just wish i had knew this when i got it cut the first time

Thanks for any help. it is much appreciated.

Brian

[toadster]

hacksaw will work, just make sure you have an aluminum capable blade, I think 32TPI blade will be good
just go slow, if you go too fast you'll deal with gummy aluminum due to heat - you'll be through it in no time
also, use some WD40 or cutting oil to lubricate the cut and keep the blade as clean as possible

if you can borrow a sawzall, less TPI but will get through quicker

[bkhicks66]

Thanks Toadster

[Snowman]

What brakes are you using that require that ear to be cut off?

[Alphamacaroon]

What brakes are you using that require that ear to be cut off?

Curious along with Snowman. That doesn't look like an ear I remember cutting off... If you cut that off, do the calipers only get one mounting hole?

[michael everson]

The smaller brakes to fit under 15 inch wheels requires this. OP make sure you check the lug hole fit on the rotors. I found that the holes weren't big enough causing the rotor to not sit flat.
Mike

[bkhicks66]

I am using the 11.65" Rear IRS Brakes that your order from FFR. According to the instructions, you remove the top bolt that connects the hub to knuckle...that is where the upper caliper is mounted. I am planning to use 18" wheels. I may make a phone call to FFR today before i get to cutting.

Link to instructions

https://www.factoryfive.com/wp-content/uploads/2020/02/IRS-2015-11.65in-BRAKES.pdf


Brian

[Paul2STL]

Curious along with Snowman. That doesn't look like an ear I remember cutting off... If you cut that off, do the calipers only get one mounting hole?

He is running the rear brake kit from factory five. I believe it is a 99-04 Mustang rear brake caliper with an adaptor plate. You have to do this to clear the 17" rims and with out modifying the calipers. I ran the stock 2015 mustang calipers and used the stock mounting holes. I got a complete drop out from a mustang that came with the calipers so it was cheaper then buying FFRs kit. Had to grind off the top nubs to clear 17" rims just a bit though as all 15 and up mustangs come with 18" stock rims or larger. This is why FFR makes that bracket to bring the caliper closer into the center of the hub so 17" rims can be used. You have to cut off the factory upper caliper mount to get the new position of the caliper to clear. You also have to do this with the Wildwood set up for 15" rims as Michael Everson stated. Research is your friend in this situation. These cars are not cut and past. I believe he could get away with not cutting the ear of an use the stock location but the pad might not grab completely on the rotor as the stock positions is used with 13" rotors.

[chuckster]

I put 2016 mustang IRS brakes on my 2017 289 USRRC and they fit with no problem with 17 inch wheels. I may switch to 15 inch wheels in the future, if so I will get Factory Five 11.65 inch rear brake kit which fits with 15 inch wheels

[Paul2STL]

I put 2016 mustang IRS brakes on my 2017 289 USRRC and they fit with no problem with 17 inch wheels. I may switch to 15 inch wheels in the future, if so I will get Factory Five 11.65 inch rear brake kit which fits with 15 inch wheels

Don't believe that is the case. My understanding is that the 15" wheels will not fit unless you run Wilwood brakes with a special set up. I have the performance pack rear brakes that may be why you don't have a clearance issue. The performance pack on the mustang gave you 13 inch rotors in the rear and I believe a different caliper design. Stock mustang rear rotors are 12.6".

[michael everson]

Brian you bought the wrong brake package for your application. That brake kit is for 15 inch wheels I believe. If it was me, I would just go to your local parts store and get rear calipers and rotors for a 2015 Mustang GT.
Mike

[bkhicks66]

Ok....I almost made a rookie (not so smart) mistake that would have cost me time and money....I have not cut anything so that is good....I determined that I have M-2300-MR rear brakes from Ford....I purchased them from Mike Forte instead of FFR. Not sure why I thought I purchased them from FFR. Has anyone used these brakes?

[Paul2STL]

Ok....I almost made a rookie (not so smart) mistake that would have cost me time and money....I have not cut anything so that is good....I determined that I have M-2300-MR rear brakes from Ford....I purchased them from Mike Forte instead of FFR. Not sure why I thought I purchased them from FFR. Has anyone used these brakes?

Those are stock mustang 15-17 calipers you do not want to cut that ear off. Those are the mounting holes for the caliper bracket. Also call FFR they will sell you the parking brake cable that will go with those brakes if you don't already have them. Also ask for the little adaptor for the parking brake arm on these brakes. The park brake cables come with a ball on the end of it. Look up the IRS brake installation instructions on FFRs website and you will understand what I am talking about.

[Padawan]

I'm running 15 inch wheels....

I used an angle grinder along with a polishing disk... cut like warm butter...

[ProJoe]

personally I wouldn't waste your time or effort trying to make such a small cut with something like a sawzall. get yourself an angle grinder and high-abrasion flap disc (like 50-100 grit).

it'll make quick work of it.

[sohcrates]

Ok....I almost made a rookie (not so smart) mistake that would have cost me time and money....I have not cut anything so that is good....I determined that I have M-2300-MR rear brakes from Ford....I purchased them from Mike Forte instead of FFR. Not sure why I thought I purchased them from FFR. Has anyone used these brakes?

Hey, did you ever figure this out? I also got my IRS center section, brakes, and knuckles from Mike Forte. It looks to me like these brake cailpers will bolt straight to the spindles no problem. Is there a clearance issue in doing this? I am using 17" wheels. The FFR instructions for the 13" rear brakes show a bunch of brackets they use to install the calipers on the spindles. I don't have those, and the calipers in those instructions look different from the ones I have.

[michael everson]

Sohcrates. FFR supplied those because they were using the older T-bird calipers instead of the mustang ones. The Mustang ones will work just fine as is.
Mike

[sohcrates]

Thanks for the quick reply on that. I have seen your name many times here. I'm also in mass. Sorry I was slow to respond. I had a login issue and then got caught up at work. I will definitely rest easier that I have the right brakes and they should be as straightforward as they seemed. Funny that my rear brakes are bigger than my fronts though....might have to rectify that at some point!

[michael everson]

You can rectify that with 95-2001 cobra front brakes. Direct bolt on. Where in MA?

[sohcrates]

I'm in Belmont. That's good to know. I like direct bolt on. I wonder if I can get any value for the 11" Front brakes FFR sold me?

[michael everson]

Not really worth much. I have about 5 sets here. If you ever need assistance, my shop is in Norton. 185+ FFRs and counting.
Mike

[sohcrates]

That's a lot of FFRs! Thanks for the help. I will definitely shout when, and not if, I get stuck!

[sohcrates]

Are these the ones you are talking about?

https://lmr.com/item/SVE-2300S/mustang-sve-cobra-front-brake-kit-94-04-stock-rotors