Rear Brake Caliper Questions

[Alphamacaroon]

Hi all,

Received my kit in March and got on the phone with FFR yesterday when they said my rear brake calipers will be on backorder until at least July... Seems like a long time to wait for a fairly common part. So at this point I'm thinking of just asking for a refund or credit and sourcing them myself. A few quick questions:


I have the IRS with 13" rotors and 18" rims— will any 2015 13" mustang caliper fit?
Do I really need to use the complicated mounting brackets they supply with a stock caliper? Can't I just mount a stock caliper to the knuckles? Some discussion here https://thefactoryfiveforum.com/showthread.php?28002-2015-IRS-13-quot-rear-brake-option seems to say it's possible, but that is for a roadster. I just get this impression that maybe those brackets are used because FFR got a sweet deal on some calipers but they don't fit the IRS knuckles.
Does anyone have a part number or approximate value of the rear 13" calipers when I go to ask for a credit?


Thanks!

[Clover]

I just so happen to have two from a salvage rear end I got for the 3.73 torsion rear differential. They have about 30K miles on them I believe. I got a new set with my kit and then ended up with the extra set from the rear end I purchased. I'm sure my wife would rather I sold them then held on to more "spares."

I'm don't know if you need anything more then the calipers or even how much is a reasonable amount to sell them for. Send me a PM if you are interested and we can figure it out.

[Gordon Levy]

I have a couple of low mile used ones, we upgrades to one of my Wilwood kits.

[Dave Tabor]

Hi all,

Received my kit in March and got on the phone with FFR yesterday when they said my rear brake calipers will be on backorder until at least July... Seems like a long time to wait for a fairly common part. So at this point I'm thinking of just asking for a refund or credit and sourcing them myself. A few quick questions:


I have the IRS with 13" rotors and 18" rims— will any 2015 13" mustang caliper fit?
Do I really need to use the complicated mounting brackets they supply with a stock caliper? Can't I just mount a stock caliper to the knuckles? Some discussion here https://thefactoryfiveforum.com/showthread.php?28002-2015-IRS-13-quot-rear-brake-option seems to say it's possible, but that is for a roadster. I just get this impression that maybe those brackets are used because FFR got a sweet deal on some calipers but they don't fit the IRS knuckles.
Does anyone have a part number or approximate value of the rear 13" calipers when I go to ask for a credit?


Thanks!

Does anyone know the rear caliper type/part-number supplied by FFR with the 2015 Mustang IRS setup?

Thanks,
Dave #17

[CraigS]

When I did 2015 IRS retrofit on my roadster I used the brakes that came w/ the salvage rear suspension. I am running 17x10.5 Bullits and they fit the calipers just fine.

[Alphamacaroon]

Does anyone know the rear caliper type/part-number supplied by FFR with the 2015 Mustang IRS setup?

Thanks,
Dave #17

I was told by FFR that they are from a 87-88 t-bird, so closest I can tell they are 18-B4508 and 18-B4509 (but I have not confirmed with FFR). They also said the stock Ford IRS calipers would work, but I'm not 100% sure if they meant they would work with the included rotors or if you'd have to get different rotors. The stock calipers made for the IRS knuckle appear to be FR3Z2552F and FR3Z2553F, but funny enough the price for both of them seems to be almost as expensive as ordering an entire IRS rear brake set (M-2300-MR https://performanceparts.ford.com/part/M-2300-MR).

And thanks all for the used caliper offers, but I'd like to stick to new/re-manufactured.

[chuckster]

I bought a salvage rear IRS off a 2016 mustang. I then bought a POR15 caliper paint kit, the calipers look like they are Powdercoated. 500 miles and they still look.like new. I picked up a pair of drilled and slotted to complete the rear brakes. I’m running 17’s and everything clears nicely.

[Dave Tabor]

I was told by FFR that they are from a 87-88 t-bird, so closest I can tell they are 18-B4508 and 18-B4509 (but I have not confirmed with FFR).

What I'm really trying to figure out is if there are any performance/track pads available for the calipers that come with the 13" IRS brake setup from FFR.

Unfortunately, I threw away the parts boxes some time ago.

Thanks,
Dave
Gen III Coupe #17

[CraigS]

Dave it's been a while but back in the day some T-bird/Lincoln calipers were a popular DIY upgrade. I looked into them but found very few performance pads, particularly Hawk available so I never did that. The current IRS calipers I am using have a wide range of of Hawk compounds available.

[Slider]

Got the IRS in the Coupe this weekend, and somehow just now realized that FF did not include the rear brakes with the IRS kit. Somehow it seems that I missed that when I placed the order. Since it appears that FF is backordered (from the messages I'm seeing above), can I just order this, https://performanceparts.ford.com/part/M-2300-MR, directly from Ford (or source elsewhere) and install without any other issues to consider? Is there any reason I'm better off ordering this directly from Factory Five? Parts missing, the kit from Factory Five are better brakes, etc?

[Alphamacaroon]

Got the IRS in the Coupe this weekend, and somehow just now realized that FF did not include the rear brakes with the IRS kit. Somehow it seems that I missed that when I placed the order. Since it appears that FF is backordered (from the messages I'm seeing above), can I just order this, https://performanceparts.ford.com/part/M-2300-MR, directly from Ford (or source elsewhere) and install without any other issues to consider? Is there any reason I'm better off ordering this directly from Factory Five? Parts missing, the kit from Factory Five are better brakes, etc?

My FFR contact said that a standard Ford brake set made for those IRS knuckles would work. So I would say that the chances are good that the M-2300-MR would work, but you'd probably be best off to call them to confirm.

[Slider]

My FFR contact said that a standard Ford brake set made for those IRS knuckles would work. So I would say that the chances are good that the M-2300-MR would work, but you'd probably be best off to call them to confirm.

I did check with Factory Five. They said this kit would fit/work just fine. Order from 2 different suppliers only to find out they were a month out on delivery as well (even though the website said they had them in stock). Cancelled those orders and did find them in stock at American Muscle. They are due to arrive today and I hope to install this weekend

[Slider]

I did check with Factory Five. They said this kit would fit/work just fine. Order from 2 different suppliers only to find out they were a month out on delivery as well (even though the website said they had them in stock). Cancelled those orders and did find them in stock at American Muscle. They are due to arrive today and I hope to install this weekend

Just following up. I installed the rear brake kit referenced above (Ford M-2300-MR). It went in easily.

[Alphamacaroon]

Excellent news. Assume the e-brake connected nicely as well? Very tempted to go this direction myself if my calipers don't get here soon. Luckily I've been able to find plenty of other stuff to do, but the time is nearing...

Would love to see some pictures!