'96 Upgrade Procedure for '94 - '95 SHOs
Thanks to the fact that Ford is bright enough to do a reasonable amount of modular engineering, if you own a 1994-1995 SHO there is a very straightforward upgrade that can be done to the front brakes. This upgrade can provide a significant improvement if you want some additional stopping performance for whatever reason. The front brakes on the 1996 model SHO used larger front rotors (11.5" diameter instead of the 10.5" diameter on the 1995 model) with a caliper bracket that is compatible with the caliper and steering knuckle of the 1994-1995 SHO. The upgrade entails removing the old rotors and brackets and installing the parts from a 1996 model in their place.
While the calipers and pads do not need to change, the mere increase in rotor diameter increases the lever arm through which the calipers apply braking torque to the front rotors. This increase in lever arm from the 10.5" diameter rotor to the 11.5" diameter rotor is over 9.5%, which translates directly to improved performance in maximum braking. Another way to quantify the improvement is through "brake swept area", or the area that the pads have available to apply pressure to the rotors. Even though the pad size doesn't change, the increase in diameter again provides an increase in the swept area.
The bigger rotors are, of course, heavier, which is never a good thing when overall performance is your goal, especially for things that rotate. For brakes, however, additional mass also means additional heat sinking capability, so it is not all a bad thing. When you're trying to get stopped the kinetic energy needs to go somewhere and the job of the brakes is to turn the kinetic energy of the forward motion of the car into heat energy. So having a larger mass to sink the heat that the brakes generate does actually help. This is also why it is very important for performance driving to pay attention to heat management of the brakes, either through your driving style or possibly through providing supplemental cooling air to the rotors and/or caliper.
That's enough for general background, but I'll give you a little bit of specific background for this particular brake change just so you know what you're reading about and looking at. I bought my SHO new in 1995, and it's been my daily driver essentially ever since. Since for several years I relied on it as my sole transportation, I was reluctant to take it to the track and let it stretch its legs, although clearly it really, really wanted to. Several of the traffic enforcement officials in my area can attest to this. A few weeks ago I happened to notice that NASA was holding an event at Phoenix International Raceway during an upcoming weekend so I signed up. I've been meaning to get this brake upgrade done for a long time, and knew I wouldn't quite have all of the parts rounded up in time for the NASA event. Since my car still had the original brake fluid, I wanted to bleed the brakes before going to PIR but I couldn't find anyone willing to help on short notice and didn't get it done. I did manage to check the thickness of the stock pads, and since they had about half of their original thickness left I deemed them ready for the track. I did take the new set of pads with me just in case, but I didn't want to use them on the old rotors if I didn't have to.
I had a great time at PIR, although I was careful to take it easy on the brakes since I was worried about boiling the original fluid. As it was, by the end of the day I had glazed the front pads and the pedal was much softer than it had been previously and often took a short pump or two to get up to a comfortable level for braking (i.e., I did boil the fluid a little bit). Shortly after the trip to PIR not only did my caliper brackets, bolts, and rotors arrive, but the set of four speedbleeders I had ordered as well. Once I had procured some 500F dry boiling point fluid and some silicone grease, I was ready to do the upgrade.
The full parts list is available on the SHOtimes website, specifically here
Follow the links for Modifying the Taurus SHO -> Brake Upgrade Packages.
Since that list seems to be complete and accurate, I will not repeat it here. In fact, I'll just provide some general info and a few details that are not available on SHOtimes.
A few helpful hints, though:
There are two bolts that hold the entire bracket/caliper assembly to the front knuckle. These bolts are important since they carry all of the load of the braking torque for the front brakes, which is essentially all of the braking effort for the car, especially under heavy braking. If you don't believe me, compare the relative sizes and weights of the front and rear rotors and pads. Since there is substantial weight transfer from the rear to the front wheels under braking (just some high school physics going on there), the front brakes do the majority of the work. This is why they get all of the beef, so to speak, and why front brake upgrades help so much. More to the point, though, this is why those two bolts holding the front caliper brackets to the knuckles are fairly important. The part number for these bolts is included in the list on SHOtimes, and it is a good idea to order a set when you order the caliper brackets. Other than a junkyard, I think Ford is the only source for these parts, so it is easy to order them together. The bolts can be easily ordered as a set of four and when I got mine they were even packaged together four in a bag. They come with the appropriate threadlock material already applied, which is yet another reason to order new ones when you do this job.
If you're like me, having the wheels off to do the parts changes is a great excuse to bleed the brakes at the same time. In my case I pretty much had to since I'd boiled the fluid already anyway. To make the job easier I ordered some speedbleeders, which are just replacement bleed screws that have a small check valve built in. This makes them more expensive than the stock bleed screws, but the check valves prevent air or old fluid from being drawn back into the caliper when the brake pedal is released during bleeding. This makes one-man bleeding a snap, and I wouldn't hesitate to recommend these things for this application. The speedbleeder web page (http://www.speedbleeder.com) indicates that their parts are milled from english dimension hex stock so that they aren't available with metric heads (i.e., you need to use inch dimension wrenches to tighten and loosen them). However, when mine arrive a 3/8" wrench wouldn't fit on them, but a 10mm fit fine. The stock bleed screws were 11mm, so this is no big deal. The speedbleeder part number that fit all four stock calipers on my car was SB1010S.
The first thing you may want to do when bleeding the brakes is draw a fair amount of the old fluid out of the reservoir that you can. A common trick to do this is to use an old turkey baster or something similar to suck out the old fluid. On my car, the reservoir cap houses a float and sensor that monitors the fluid level, and the guide system for the float prevents getting a baster, hose, or anything else useful far enough into the reservoir to draw out much fluid. Bummer. This just means that you need to do a lot of pumping on that first caliper to get all of the old fluid out of the reservoir, through the lines, and out the caliper.
When bleeding brakes on a 1994-95 SHO (perhaps all of them, I think), start with the longest line in the longest circuit and work your way to the shortest line in the other circuit. This means that the lines are bled in the following order: right rear, left front, left rear then right front. For the unfamiliar, the right side of a car is the passenger side (at least in North America and some other enlightened regions).
A little more on bleeding later, but this article was supposed to be about a brake upgrade, so we'll proceed.
Removing the old parts on the front is reasonably easy. I would suggest obtaining the Chilton's manual that covers 1994-95 Tauruses (typically available at places like Pep Boy's, Checker Auto, etc.) since it has all of the appropriate diagrams, procedures, hints, etc., for most mundane service on the chassis and even some SHO engine issues. This manual also shows which bolts hold what together, appropriate torque values, etc. The manual is not absolutely necessary, but if you have trouble following the descriptions here, it's probably a good investment and it's good for a lot of other maintenance related to the car as well.
After suitably securing the car with the parking brake or appropriate blocks, chocks, or whatever at the rear wheels, jack the front side of the car that you will be working on. The hardpoints for jacking the front are at the unibody weld joints just behind the front wheel wells. Check your owners manual or the instructions that come with the factory jack. The Taurus is a pretty lightweight unibody, so a lot of places under the car that look like they're strong for jacking, aren't. I've learned to just always use the factory hardpoints. If you want to secure with a jackstand, there are some recommended places under the front subframe. YMMV. Jack the appropriate front corner and remove the wheel and tire assembly.
There are two bolts that hold the caliper to the slide pins that reside in the caliper bracket. They are near the two ends of the caliper on the back side facing away from you. After the second bolt is removed the caliper can be slid off the wheel leaving the pads and bracket behind. Have a peice of wire or other suitable device handy so that when you remove these bolts you can hang the caliper on the front spring. This is important so that the flexible part of the brake line doesn't get stressed or damaged. Mind the brake line when you handle the caliper and hang it so that the line isn't crimped or kinked.
The pads float freely in the bracket, so they'll just be sitting loose in the bracket once the caliper is removed. Remove the old pads, as you probably don't want to use them on the new rotors anyway.
Now to the two aforementioned bolts that hold the caliper bracket in place. These are originally torqued at 85 ft-lbs and have threadlock on them, so they can be difficult to remove if they've been in there a while. I had just bought a vertical compressor, hose, hosereel, and air impact wrench on the sole excuse that I would need all of that to get these bolts out. When I went to remove the first bolt it wouldn't budge even after soaking with WD-40 and the impact wrench set on max torque. I was mangling the socket so I went to Lowe's and bought a metric impact socket set and a three foot cheater bar cut from some thick conduit. The impact wrench still wouldn't budge it, but I wound up removing all of these bolts easily with the three foot cheater bar and a 3/8" socket wrench. So the $400 I spent on air was defeated by my $4 cheater bar.
Once the caliper bracket is removed, the rotor can be removed. On my car the rotor was held in place by circular ring clips on a couple of the wheel studs. If you're careful about removing these you can reuse them to hold the new rotors in place. I just unscrewed them from the studs with my fingers after starting them with a small screwdriver, hint: use gloves. If the rotor is still stubborn after removing the clips, tap it lightly with a rubber mallet to try to coax it free. A little WD-40 around the center probably won't hurt, either. Mine both came off easily, but there are instances where these things stick sometimes.
Figure 1 shows the front assembly with the rotor and caliper bracket removed, and the caliper hanging above. The old rotor is seen already removed from the vehicle.
Figure 2 shows a side by side comparison of the old and new rotors. The size difference is evident, and this is the entire reason for doing this upgrade.
The new caliper brackets are compared in Figure 3, and the additional length of the new bracket on the right to fit the larger rotors is evident as well.
The new rotor should slide easily into place. I cleaned mine with a brake part cleaner first, to remove any residual oils or dirt left over from manufacturing. The Chilton's manual recommends applying some silicone grease around the center hole before installation, so I did this as well. I'm not sure what the purpose of that is but it may make removal easier later on. If you've kept the ring clips, these can be installed to help hold the rotor in place while you put the rest of the assembly back together.
Figure 4 shows the new rotor installed. The caliper can be seen hanging from the front spring.
With the rotor in place, the new caliper bracket can be installed. The guide pins on the brackets I received were pre-lubed and protected with rubber boots. The old brackets had rubber boots on the pins as well and they still slid quite easily even after seven years of hot-weather duty (I live in the Phoenix area) so this appears to be a pretty good system. Install the new bolts (or, if you're bold, the old ones with appropriate threadlock applied). My Chilton's manual indicates that these should be torqued to 85 ft-lbs.
Figure 5 shows the new caliper bracket installed.
Before installing the new pads and the caliper, it is necessary to seat the piston back in the caliper to accomodate the thickness of the new pads. This is most easily done with a 4" C-clamp and something placed across the piston (don't apply a tool, like the clamp, directly to the piston). A piece of wood can be used, or even one of the old pads. An easy thing to do, especially if you're going to bleed the brakes anyway, is to open the bleed screw before squeezing the piston back into place. This allows the fluid to escape the caliper through the bleed screw rather than all the way back up the brake line, and also keeps from blowing dirt and old fluid back into the master cylinder. It is also much easier to seat the piston this way. Do this step before bleeding the brake line to this caliper.
I bought Performance Friction Carbon Metallic pads to replace the old stock pads, they're Performance Friction part number 6014. They produce more dust than the stock pads but have presumably stickier material than stock.
The pads sit freely against the rotor in the caliper bracket and be sure to apply the metal insulators that come with the pads. Figure 6 shows the installed rotor, bracket, and pads with insulators before the caliper is installed.
With the caliper piston already seated, the caliper should slide easily over the new pads. Install the bolts holding the caliper to the bracket guide pins. Chilton's indicates that these bolts should be torqued to 23-28 ft-lbs. I torqued mine to 25 ft-lbs.
Figure 7 shows the installed assembly with the new speedbleeder installed and the bleeder hose in place.
With the caliper in place the brake line and caliper can be bled as shown in Figure 7. Once the bleeding is done, the tire and wheel can be replaced. The same procedure is followed for the opposite side of the car. Once both sides are finished, it is a good idea to do some simple static tests like making sure the brake pedal is hard and stays up with pressure and the brakes can hold the car still against some gentle force from the engine. It is advisable after brake work or work on any safety related system to be cautious until it is clear that basic functionality has been restored.
It is not a bad idea to peruse the other guides on SHOtimes pertaining to brakes before performing this upgrade if you haven't done anything like this before. It is also a good idea to read Gary Morrell's guide and the information related to seasoning rotors and bedding pads. Since the rotors and pads will be new (it is a good idea to use new pads with the new rotors), braking efficiency might be a little diminished at first until everything is adequately seated. I see no reason to think anything won't be safe, it's probably just not a good idea to go challenging descending mountain curves at high speed the first thing after installation. I would suggest taking a few days of normal driving to not only seat the new materials but to get used to the feel of the new brakes. I took it easy on them for a few days (actually what I did was probably back off to what most people would call normal driving) but the improvement was very noticeable. Of course in my case the immediate comparison was to a spongy system with glazed pads, so of course it was better, but it is even noticeably better than it has ever been.
Since this installation was completed I managed to get the SHO to another track event, this time to Firebird raceway using the main road course connected to the drag track. We used a configuration which included the carousel from Bondurant's track, so the front straight was very long and I was braking from 95mph into the sweeping entry of the carousel. At the other end of the course is a one-hundred-eighty degree turn leading onto the drag track which also has an entry that requires hard braking. We drove quite a few sessions and the new brakes held up quite well. The first sessions were in ~110F ambient, so the track temps were extreme. (This was an afternoon into night event, so the later sessions were after dark in much cooler conditions.)
The performance of the new brakes is significantly improved over the old. At Firebird I experienced no fading, good stopping effort, and a solid pedal through the entire event. But I would echo Scott Chan's opinion in that these aren't racing brakes and shouldn't be expected to perform as such. The stock SHOs are somewhat underbraked for their size and supposed performance heritage. This modification is a good step in the right direction but doesn't result in the throw-you-against-the-belts performance of good racing brakes. For the sorts of things I do, including track events, they're fine as long as the limitations are recognized. Improving braking is generally always a good thing, IMHO, and this modification gets a lot of bang for the buck over the stock brakes.