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Repost of "Ford Racing ABS Installation"

Marshall M.

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The links went dead in my first thread and for some reason that ID got picked up as something to do with spamming, so I'll re-do over here.



I’m posting this to document the conversion of standard SN-95 ABS from my FOX Mustang over to the new “oh my God” Ford Racing ABS…


The first thing to consider is the location and mounting of the ABS unit itself. My SN95 ABS unit is/was in the passenger floorboard. Therefore, I already had all the lines (2 supply and 3 outlet) run around the car.


The stock HCU bracket could be easily manipulated to mount 2 points to the floorboard and I built a simple spacer to mount the third point. The mount has plenty of vibration isolation, so you can grab and shake the HCU in the mount. This gave me good feelings that vibration from the car during a race would not cause excessive issues with the HCU and ABS electronics.


The stock supply lines and outlet lines were “close enough” to just cut and flare for a simple union fitting. For the new lines going into the HCU, I just purchased AutoZone double flare 3/16 line. This was good for 2 of the 6 lines, but the other four required that line, but a M12 conversion nut to be purchased. You can also get these at AutoZone, etc. I also removed the rear prop valve, as the FR500 unit does that on it’s own. I did have to run a second rear line, as the S-197 system is a 4 channel and the SN95 is a 3 channel system. This consisted of just another few sections of 3/16 line running parallel to the original rear line.


If you want to flip flop back and forth between ABS/no ABS, install the prop valve in the rear supply line BEFORE the HCU. That would allow you to run wide open (no pressure drop) for ABS function, or reduce the pressure if the ABS is disabled. I chose not to do this, as I’m going to “set it and forget it”.


The only harness you need to source from a junk yard is the ABS plug.



Here is the plumbing layout for the HCU



Here is the wiring diagram. For older cars, I just ignored the PCM portions.



The brake position switch can be made from a 5 pole 30A relay.



The speed sensor wire colors from the SN95 system match this diagram, so that is pretty nice…



I don’t have any pictures of the wheel speed sensor mounting, but it’s a simple redrill/tap for the new clocking on the S-197 sensors. The SN95 were just a magnet pole sticking out, so there was no orientation required. To drill/tap the rear caliper brackets, I found it easier to just remove the axles from the car and remove the caliper mounting plates from the axle and drill on a drill press.


The front spindles on my car didn’t want to come off easily, so I drilled by hand on the car. Not the easiest, but worked fine.



All in all, I would put the installation difficulty at a 6 out of 10. Not super difficult, but time consuming to lay out in your head and then it’s just time… Having a welder, drill press, and overall shop tools was nice, but you could probably get away without them.


I’d say that since I had ABS on the car already, this entire conversion (not counting my time) was about $1100 in parts


$525 HCU

$50 ABS harness

$125 wheel speed sensors

$260 FR ABS Module

$25 Brake Fluid

$75 Brake Line and fittings

$25 Diff fluid and gasket

$15 5 pole relay with harness



The only thing I haven’t addressed at this point is the diagnostic port (Module Communications Network) section 14-2 on the diagram. I still need to do research on how to wire an OBDII port to these wires so I can trouble shoot the system.




Here is the parts list of what you will need to buy…





ABS Module

You want the "M-2353-A" sensor. The -A part is the FR500S module. The -B and -C are the same module for the new Boss cars, just with or without the bracket. I would guess the tune is for Pirelli slicks.



Wheel Speed Sensors

BRAB-290 (rear)

BRAB-291 (front)


This is the cheapest place I could find and it was free shipping. They are Motorcraft parts.

These sensors plug into the stock SN95 plugs and are approximately the same length as the SN95 harnesses, so you shouldn't have to manipulate the body harness.



Also, some lessons learned from the first thread.


1. The FR ABS module was too much for my car/driving style. I got WAY too much rear brake on trail braking and had corner entry oversteer. I tried several different rear pads and couldn't get it to behave so I ended up going to the GT500 module. It works much better for my application.


2. Another racer in TX is trying to see if the SN95/SN99 wheel speed sensors will work, as they are still a 2-wire sensor. That would keep you from having to re-drill the spindle and adjust the clearance between the exciter ring and the sensor. I haven't had any issues with the wheel speed sensors, so probably won't go back to the old style.

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  • 8 months later...

Any chance we can get the links restored? I can host them if necessary.


I got the GT500 HCU with GT500 module.


I run a fox body in autocross. Moving from 'C' prepared to CAM-C class which allows me more modifications.


Currently running C6 vet front calipers and Varga C4 HD rears, AX6 pads on all four. Brakes are currently manual. Ran the CNC-241 dual master with 3/4" MC's last season but not happy with the performance. I have a Hydratech hydro boost on order.


Couple of questions:


1. Anyone have the wiring diagrams, pin out charts? Looking for the stock GT500 and the FR500 info.

2. What about bleeding the system, do I need any special tools to activate the solenoids in the HCU? Or will a simple pressure bleed work?

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Ill be doing the install in Jan. on my FFR.


Couple of things to note.. I found a part# that has HCU and control module and bracket

ABS MODULE WITH HYDRAULICS BOSS 302R/S HCU M-2353-BA https://www.shopcapaldiracing.com/store/boss-302r-abs-module-w-block.html


(may need FR500S abs module M-2353-A https://www.shopcapaldiracing.com/store/500s-abs-brake-module.html )


I found the ABS harness on amazon here

ABS Connector $41.36 Motorcraft WPT1234 Pigtail Assembly http://www.amazon.com/gp/product/B009B5ST58?psc=1&redirect=true&ref_=od_aui_detailpages00



and the bubble flare fittings you need you can get at any autoparts store

Fittings (to calipers) – 4 of 10M x 1.0 bubble flare to 3/16 line

Fittings (from master cylinders) – 2 of 12M x 1.0 bubble flare to 3/16 line

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I just picked up a low mileage 07-09 GT500 unit off ebay for $200 (HCU w/GT500 control module)


Here's the wiring diagram for the HCU






Here's the C135 wiring harness connector pin out






Here's the ports and sizes






Good find on the wiring pigtail!!

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M-2353-BA is complete with pump, bracket and module.

The pigtail you referenced is for the earlier ABS and will not fit M-2353-BA

M-2353-BA went back to inverted flairs for some reason.

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M-2353-BA is complete with pump, bracket and module.

The pigtail you referenced is for the earlier ABS and will not fit M-2353-BA

M-2353-BA went back to inverted flairs for some reason.


I have both wire pigtail wpt1234 and m-2353-ba and they plug into each other. Not sure if you are referring to another pigtail but what I got works

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The WPT-1234 is a 38 pin connector. Searching it's part # BU2Z-14S411-BAA it's shown listed for 2011-2015 Mustang (all models) along with F150's and Super Dutys.


The pin-out (C135) for the 07-09 GT500's shows a 46 pin connector. The 46 pin connector is WPT-1356.






Here's a picture of the FR500s vs. GT500 ABS module.



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Ok found this for the WPT-1356 pigtail


The listing for the WPT-1356 is E350. Under w/Adav tech wiring I found the following pin connector and the replacement pig tail called out is the WPT-1356.




The replacement pigtail shown




The image lists it as the WPT-1234 but if you search the BU2Z-14S411-BBA part number it's a WPT-1356. The image also matches the Motorcraft wiring harness catalog pic.


The problem is the pin out between the WPT-1356 and the GT500 Module.


If you compare the pin outs the E350 C155 connector (what the WPT-1356 replaces) has (5) extra wires (10, 20, 24, 34 & 39) not used in the C135. One important pin is not wired #6 which is voltage supplied all the time.


You can probably move one of the (5) extra wires into the #6 spot.

Edited by Guest
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Thanks John, that helped me decide which pigtail I needed.


So what you have is a Boss 302 2010 up ABS module and HCU.


The plug is different than the 07-09 GT500 and FR500S module. I assume the FR500s module bolts onto it but the connector doesn't seem like it would work.


I ordered the WPT-1356 (BU2Z-14S411-BBB) pigtail, I'll update what I find on the wiring. Even if I have to remove (4) wires and relocate one it's still better than a junk yard harness.


Thanks for the input John!

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What is the difference in how they work, feel, intrusiveness, etc between these?

-2009 GT500 HCU and M-2353-A (FR500S module - 46pin connector)


2010+ ABS MODULE WITH HYDRAULICS BOSS 302R/S HCU M-2353-BA (38pin connector)


and, can I just buy the M-2353-A (FR500S module - 46pin connector) and install it on the M-2353-BA HCU I have already?

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From only what I have read the FR500S is calibrated to Grand Am Cup Series slicks.


The GT500 is calibrated to street tires.


I'll be running the ABS in the CAM-T class which is a 200 treadwear tire class.


In C-Prepared where I can run my Hoosier A7 slicks I can't use the ABS.


So based on that I am sticking with the GT500 module for now.


Hopefully some of the guys with actual experience with any of the units can provide some feedback.

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My WPT-1356 Pigtail came in.


I took the plug apart, relocated wire 10 to 6 and removed wires 20, 24, 34 & 39 that are not required. Took all of 5 minutes.


If you go this route remember the plug is wired as C155 (from an E350) as shown in previous thread and needs to be modified to match C135 (2009 Mustang) as shown in previous thread above.



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Correct, I meant CAM-C as of last years rules which listed cars only up to 73' for Mustang in CAM-T.


These new rules show I can run CAM-T if I am reading it right (w/o ABS). Says up to 89' but then lists 93' Mustang.


They added 200 lbs to CAM-C also.

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  • 2 weeks later...
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So based on that I am sticking with the GT500 module for now.

Hopefully some of the guys with actual experience with any of the units can provide some feedback.


I started with the FR module, but have changed back to the GT500 module due to trail braking oversteer that I couldn't dial out with rear pad compounds (tried four different ones).

I'm much happier with the predictability of the GT500 module. It's much less "squirmy" under hard braking and easier to save if you go too deep since you don't have the trail braking issue to deal with.

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  • 2 weeks later...

OK so after looking at wiring up the 2010+ BOSS302R/S M-2353-ba module, it looks like its not possible to install stand-alone as it requires steering angle, yaw sensors, etc through RCM CAN Bus (pin 8 and pin 9) on the C135 connector (see pdf here on page 3: https://fordperformanceracingparts.com/download/boss302spdfs/2014/electric/M-14290-M302C,%20Forward%20Lamp%20w%20ABS%20-%20Rev3%20(2012.7.15).pdf)


If anyone needs M-2353-BA and pigtail its up for sale


So, I purchased Mustang GT500 HCU and M-2353-A FR500S module from Ebay, and will be installing it as soon as it comes in. Sorry for the confusions I was assuming newer models were also stand-alone install-able but that does not seem its the case.



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Started on the ABS install over the weekend! welded mount to frame, ripped out all of the brake lines, ran rear lines forward to ABS, rewired ABS connector moving Pin10 to Pin6, removing pins 20, 24, 34, 39 (I couldnt figure out at first how to take them out, if there was a tab you had to press down, so I ended up yanking on the wires real hard from the back and they came out.)











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  • 1 month later...

Sorry John I should of done some pic's of the connector disassemble. I just used a eye glass screw driver to reach up in there and hold the tab to get the wire out. Pretty sure I had to do it from the wire side. Push the wire all the way in, lift the tab and pull gently, should come right out. If not you don't have the tab out of the way. I de-contented the entire wiring harness on my car a few years ago to remove all the unused wiring (air bag, emissions, HVAC, power windows, seats, mirrors etc.) so I have had some practice.


Need to find a mounting bracket for mine that I can modify.


My ABS install is on the back burner for now. For the winter downtime I am installing a Griggs watts link and a new 304 SS exhaust.


Plus the SCCA changed the class rules in CAM so to add the ABS now is going to cost me another 200 lbs. that I need to add to the car.


I also have a hybrid 8.8 and need to figure out how to get the ABS rings on my rear end. Need to call Moser to see what I can do.

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  • 1 month later...

Got FFR#48 on the road finally and ABS works!! I ended up upgrading the rear end to new FFR 2015 IRS which is based on the 2015+ mustang spindles/pumpkin including the 2015+ ABS sensors. Good to know that it actually works with the BOSS302 ABS module.


I have not tried it on track yet, first outing is April 15-17 @ NJMP. So far its not intrusive at all, only at extreme pressures it actually activates, and its fast, very fast pulsing.


Had to upgrade the lines from master to HCU to 1/4" size as the 3/16" size lines I was using before were leaking at the fitting (HCU is made for 1/4" line, found metric fitting that I drilled out to fit over 1/4" pipe)


Here is the final parts list I used for FR500S ABS (pics of install)


2007-2009 Ford Mustang GT500 ABS module (HCU – ebay has item, connector on back not on side, do not buy newer year model) $200

FR500S abs module M-2353-A (not sure if needed, calibrated for slicks, will try it in April 2016) $293.25

ABS Connector $51.24 Motorcraft WPT1356 Wire Assembly(relocated wire 10 to 6 and removed wires 20, 24, 34 & 39 that are not required

Tube nut fitting – 2 of 10M x 1.0 bubble flare to 3/16 line BLF-39C-5 (5 pack)

Tube nut fittings – 2 of 12M x 1.0 bubble flare to 3/16 line BLF-48C-5 (5 pack)

Tube nut fittings – 2 of 12M x 1.0 bubble flare to 1/4 (6mm) line BLF-46C-5 (5 pack)

Quantity =2 Adapter female 7/16 -24 inverted to male 3/8-24 inverted BLF-23C

Quantity =2 7/16-24 inverted flare nut for 1/4″ tube BLF-13C-5 (5pack)

3/16 brake line 25ft – AGS Poly Armour Brake Line PAC-325

1/4 brake line 25ft – AGS Poly Armour Brake Line PAC-425

Front wheel sensors (2 of them, $34.79 each) BRAB291

Front sensor mounts for FFR spindles – $45 made by Russ Thompson

{Rear wheel sensors (for 8.8 solid SN95 axles – 2 of them, $32.79 each) BRAN290} didnt use due to IRS install...

Wheel rear sensors (2015 IRS, 2 of them,$11.85) BRAB406



As for brake calipers, using Wilwood 6piston all around (4.04 area, 1.62/1.12/1.12), and using 7/8" wilwood master cylinders (2 of them) along with the balance bar to set bias.

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