Brakes The Ultimate 4-lug/5-lug Brake Conversion/upgrade Thread

xxjim

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Oct 5, 2019
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All, I have a TC 8.8 I am looking to upgrade to SN95 brakes. I have the calipers and stuff, but wondering which axles and rotors I need for this axle. Thought I needed 94-98 axles, but they seem too long.
 
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Mustang5L5

A little massaging and it went right in
Mod Dude
Feb 18, 2001
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TC axle shafts are 30” long. 94-98 sn95 axle shafts are the same lenght.

If upgrading to sn95 brakes on any 86-98 8.8 housing, the 94/98 axles are what you need when using unmodifird sn95 brake axle flanges
 

fox racer v2

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Jun 2, 2019
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Alright folks, after a short 15 year hiatus from the site/mustangs and a fresh new "v2" username due to a lost password, I am back in the game and tackling how I want to approach my 5 lug swap. Namely, the 3-to-2/stock proportion valve changes - I want an OEM quality & look, so a few scenarios I think get us there:

1. Gut the rear of the stock prop valve, tap the back of stock prop valve 1/8" pipe thread, find an adapter with 3/16" ISO flare 10mmx1.0 metric female, and a 1/8" pipe thread male. Bend the stock driver side front brake line 90*, and plumb righ into the rear of the prop valve. Does anyone have a part number/manufacturer for this type of fitting?

2. Gut the rear of the stock prop valve, tap the back of stock prop valve 1/8" pipe thread, use the combo of:
- Edelman 262010 (10mmx1.0mm female bubble flare, to 3/16" 3/8-24 inverted flare male)
- Allstar Performance ALL501120 (3/16" 3/8-24 inverted flare female to 1/8" pipe thread) Bend the stock driver side front brake line 90*, and plumb right into the rear of the prop valve.

3. Gut the rear of the stock prop valve, tap the back of stock prop valve 1/8" pipe thread. Use Allstar Performance ALL501120 (3/16" 3/8-24 inverted flare female to 1/8" pipe thread) and reflare the stock driver side front brake line to use a 3/16" 3/18-24 inverted flare fitting (any will work). Bend the line 90*, and plumb right into the rear of the prop valve.

4. Go the tried and true MM 3-to-2 kit

I think the most realistic/cleanes is #2 above, as I don't have to reflare anything, and the fitting described in #1 appears to be non-existent. My questions are:
a. Tapping the stock PV (well, the stock plug on the stock PV) for 1/8" and using a flare adapter, will this seal properly or am I missing something?
b. Could I avoid the 90* bend if I use the 93 Cobra brake lines? I may replace all of my hard lines with a kit, but I'm unsure if the 93 Cobra lines uses ISO or inverted flares on the front driver side line (PV side).
 

Mustang5L5

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Mod Dude
Feb 18, 2001
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No need to tap the rear of the prop valve. It's already tapped and plugged. Simply remove the plug, and locate the fitting from an SN95 non-ABS mustang that goes in this spot. Unsure of the year ranges, but you want a non-ABS car.

The fitting screws into the back of the fox prop valve and then you can custom bend a line from there to the driver's front brake line. Very factory looking.

This is how I did mine. This photo isn't of my car, but it's identical in appearance. They kep is finding the fitting. It's OEM only meaning you need to track down a factory prop valve from an non-ABS sn95 and take it from that
2009_0427Image0003.jpg
 

fox racer v2

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Veeery helpful. Found a prop valve from a 96-98 w/o ABS I'll grab. This is exactly the look I'm going for and I don't have to re-flare?

Little pricey for OEM, but I've cheaped out in the past and hated the result.
 

Mustang5L5

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Mod Dude
Feb 18, 2001
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It was 10 years ago...but no I didn't reflare anything. I can check to see if I had used an additional adapter
 

fox racer v2

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Think you answered that q in an old post actually.

Can either grab a non-ABS sn95 front driver side brake line or cut/reflare to m12 ISO tube nute (stock fox is 10x1.0mm ISO).
 

Mustang5L5

A little massaging and it went right in
Mod Dude
Feb 18, 2001
32,315
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I grabbed a length of line from NAPA that was already flared, and bent it into place. I think I used an adapter on the prop valve side. I'll have to check tonight
 

Mustang5L5

A little massaging and it went right in
Mod Dude
Feb 18, 2001
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I did use an adapte unknown size, but it’s a preformed line into an adapter into the sn95 fitting

7025D18D-ED3D-48A5-B872-CE6BA58FC947.jpeg
 

fox racer v2

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Jun 2, 2019
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So I have the rear (SN95 length axles, Cobra brakes, all Ford bracketry), front (94/95 spindles, Cobra brakes), and MC/Booster (93 Cobra) figured out and will be running 98 Cobra wheels.

Curious for anyone's input on tire size - think I should be just fine running 245/45/17 at all corners? My only concern is the axle length and rear wheel fitment.
 

Mustang5L5

A little massaging and it went right in
Mod Dude
Feb 18, 2001
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I run 245/45/17 up front and 255/45/17 out back. My fender lips are rolled, but 245 should clear without touching the fenders

Same brake setup
 

Red50Fox

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May 6, 2019
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I'm (eventually) going to get to my 5 lug upgrade. I'm thinking that I want to use the sn95 prroportioning valve (F4ZC 2B091 CA) for non abs. I found one on ford only parts .com wondering if a. anyone has experience with them? or b) anyone has one. Please let me know
 

Mustang5L5

A little massaging and it went right in
Mod Dude
Feb 18, 2001
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Massachusetts
If you want it for the rear fitting go ahead, but the proportioning is not correct for a fox so you should really just gut yours and install an adjustable valve
 

Mustang5L5

A little massaging and it went right in
Mod Dude
Feb 18, 2001
32,315
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Massachusetts
What's involved with using that valve vs. gutting the existing one?
All depends on if the fitting sizes are the same. If yes, would be a direct swap other than rerouting the pass front fox brake line to the rear fitting like shown above.

Gutting the stock valve is easy. Unscrew front fitting, pull rod out, screw in new replacement fitting (from LMR). Then locate the union on the pass side firewall brake like, remove and install and adjustable.



I'm just thinking that the entire brake system is sn95 (94 gt) aand it would be more appropriate to use thar valve?
True, but the car is not an SN95. The valve is set with the weight of that chassis and tire sizes in mind.
 
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Red50Fox

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The 88 GT has a curb weight of 3340 and the 1994/95 GT coupe has a curb weight of 3276 lbs (net diff 64 lbs) and I plan to use stock tires sizes on the split 5 spoke wheels 245/45ZR17, diameter of 25.7", section width of 9.6 vs. 225/55R16, diameter of 25.7, section width of 8.9 (net width diff .5 inches). So not too much overall difference (I think). I think I'll give it a shot (but keep the original 88 valve) and see what happens. I still have plenty of time at the rate I'm going. Worst that can happen is it does not brake well and I gut the original and move on!
Thanks for the detail, I appreciate it.
 

Red50Fox

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May 6, 2019
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Hi folks, still noodling on the brake conversion and hung up on the prop valve (hard lines and fittings too) for this conversion. If I swap out the prop valve is it only a 94 - 95 non abs that I want or can I use non abs from a different year? I see that Fox Racer v2 grabbed one from a 96 - 98. Would that work? I need to get a better understanding of the brake work that I'll need to do for this. It is appearing to be more difficult than I thought :cautious:

Edit: and if I can use a non ABS from other years, how do I know it is really a non abs?
 
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fox racer v2

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Jun 2, 2019
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Don't stress it, this part is very nuanced - plenty more where these came from!

I have one from a 96 (I believe, but definitely 96-98 like you said) but don't have anything to compare it to - I won't be swapping over until the spring the earliest unfortunately. I can confirm the female end of mine is m12x1.0 however. I'm betting mine will work just fine in a for prop valve, however.