Rear disk options Exp v. Vic v. Mark

[Decurion]

I want to convert my rear brakes to disk, and the 3 common vehicles Ive heard of that make for an easy swap are the 96+ Exploder, 92-96 Crown Vic, and Mark VII. I was going to use the Crown Vic setup, but walking through the U-pick yard this afternoon I saw a Mark and noticed that it actually has vented rotors. So whats the basic pros and cons of each? As far as I can tell...
1. Explorer-
...Positive- Good strong setup, internal park brake is easy to work on, plentiful and fairly cheap.
...Negative- Kinda heavy, have to redrill caliper brackets, non-vented rotors.

2. Crown Vic- this is what I was going to use
...Positive- Lighter than Ex setup, but still very adequate, no need to redrill brackets, simple internal park brake, common as dirt, cheap.
...Negative- Still no vented rotors, some have mentioned reclocking one side???

3. Mark VII- this is the one I know less about
...Positive- vented rotors!
...Negative- less common, expensive and P.I.T.A. integral park brake

 

[ultrastang]

I want to convert my rear brakes to disk, and the 3 common vehicles Ive heard of that make for an easy swap are the 96+ Exploder, 92-96 Crown Vic, and Mark VII. I was going to use the Crown Vic setup, but walking through the U-pick yard this afternoon I saw a Mark and noticed that it actually has vented rotors. So whats the basic pros and cons of each? As far as I can tell...
1. Explorer-
...Positive- Good strong setup, internal park brake is easy to work on, plentiful and fairly cheap.
...Negative- Kinda heavy, have to redrill caliper brackets, non-vented rotors.

2. Crown Vic- this is what I was going to use
...Positive- Lighter than Ex setup, but still very adequate, no need to redrill brackets, simple internal park brake, common as dirt, cheap.
...Negative- Still no vented rotors, some have mentioned reclocking one side???

3. Mark VII- this is the one I know less about
...Positive- vented rotors!
...Negative- less common, expensive and P.I.T.A. integral park brake

There's also these two options. Simple installation, abundant parts availablity, and parking mechanisms are simple and work effectively:

SN95 V6/GT:
1. http://www.ultrastang.com/Ultrainfo.asp?Page_ID=17

SN95 Cobra:
2. http://www.ultrastang.com/Ultrainfo.asp?Page_ID=18

SN95 conversion brackets:
http://www.ultrastang.com/Ultrainfo.asp?Page_ID=20

 

[Decurion]

Is there any real advantage to one setup over another? Does the Mark bolt up the same way the others do? For what its worth, its going on my 65 comet wagon with a 9". It already has Granada disks on the front.

 

[Rusty67]

Sorry Ultrastang but I have to disagree with you here. Don't use the SN95 Mustang rear brakes, they suck. First off, unless you use the Cobra ones you are going to get a solid rotor instead of a vented rotor. Then, the parking brake is inegrated into the caliper and you need to use special service tools to retract the caliper piston. Jack screw calipers are just stupid.

If you go with the Crown Vic you will also get a solid rotor unless you get the latest Vic setup which I've heard now has a vented rotor. The advantage the Vic setup has is that it uses a regular floating caliper instead of a jack screw caliper and it has a drum parking brake inside the rotor which give you an extra friction surface and it give you a seperate system incase of brake failure. I think Ultrastang posted a link to a vented rotor for the older Crown Vic setups a few months back.

The Vic and the Exporer setup are basically the same but from what I understand, the Explorer brakes fit large wheel bearing 9" and the Vic fits 8" and small bearing 9" rears.

 

[Decurion]

Oh ya, I did hear about putting a vented rotor on the CV setup. How is that done?

 

[ultrastang]

Oh ya, I did hear about putting a vented rotor on the CV setup. How is that done?

At present, I don't think there's any easy solution to using the 2003-present ventilated Crown Vic rotors on an older Ford 8- or 9-inch rear end housing.

Typical of Ford, they changed things up on the '03-up CVs. --the axle housing end flanges are clocked in a vertical fashion instead of the normal horizontal orientation. This means the caliper anchor plates have the holes in the wrong place to bolt up to the housing's end flanges like can be done with the '92-'02 versions.

The '03-up CV rotors are not much smaller in diameter than the Cobra rotors and about the same .750" thickness as opposed to the older CV's solid .500" ('92-'95) and .550" ('96-'02) rotors. I don't think you can simply take the newer CV ventilated rotor and put it on an older CV setup due to the larger diameter and greater thickness.

In defense of the SN95 rear calipers, IF you were to buy used parts, and IF you rebuilt the calipers yourself, you would need some specialty tools to do so. On the other hand, if you bought new calipers or if you traded used calipers in as cores for new/rebuilt calipers, you would not have to fool with rebuilding them. It would just be a simple matter of bolting them on and hooking the brake line and parking brake cable up.

My daily driver for nearly the last 5 years has been a 2003 Mach 1. It has the very same rear calipers as the '94-'04 V6/GT Mustangs (only difference is the pads and the mounting bracket). I have nearly 85,000 miles on them (40-mile round-trip-commute to work and back home every day) and I've never had a minute's trouble out of them, and no problem with them holding the car in place when the parking brake is applied.

 

[88gt]

I am by no means discounting the SN95 rear brakes in this response. I installed 2000-Crown Vic rear disc's on my '65. Mounting the backing plates was fairly easy, had to open the center hole for the axle bearing to slide through and grind a very small amount of material from the axle housing, also had to make some spacers to set the axles properly.. My next chore is to configure the parking brake cables and finish plumbing the hard lines.

The C-V set-up was easier to locate in my area than anything else. One thing I have learned, don't get into a rush locating parts. Taking your time will save you time and $$ in the long run.

I also think that the solid rotor design will be just fine for a daily driver/weekend driver, if you're going to be hard on the brakes, budget brakes are not for you...

Good luck,
Jim

 

[bnickel]

my ONLY issues with the C-V brakes are the solid rotors and the clocking of the calipers, one side is in front of the axle centerline and the other is behind it. not sure if the 03 up are this way too, but at this point it may be a moot point since the housing flanges are sideways and won't bolt up directly to a mustang rear anyway. there are however aftermarket vented rotors available for the C-V brakes so that takes that issue out of play and only leaves the goofy clocking of the calipers. i don't believe the explorers have the goofy clocking issue.

i also prefer the internal drum parking brake BUT only because i'll pulling a small boat behind the cougar on occassion and prefer the drum style parking brake on boat ramps. if it wasn't for that fact i wouldn't sweat the internal drum parking brake AT ALL.

i'm also fairly certain there aftermarket vented rotors available for the sn-95 brakes as well you just have to do a little searching.

for those who may be interested in an internal drum parking brake style setup i noticed that Heidts has a setup that uses what "appears" to be a wilwood backing plate and drum style parking brake kit that uses a GM style caliper with a vented rotor that looks like it could be a viable option for a little less than a typical aftermarket rear disc kit (about $600) there is also the vintage venom kit as well, http://www.vintagevenom.com/mustang-rear-disc-brake-conversion-kit.htm, but this kit is apparently not the same as their old rear disc kit that had vented rotors, not sure what's up with that though.

like i said, if it wasn't for that fact that i'll be pulling a boat with my cougar i'd use one ultrastangs rear disc kits and save a bunch of money over an aftermarket kit. that's my opinion so take it for what it's worth but i think that 98% of street cars will work just fine with one of ultrastangs rear disc kits vs the internal drum brakes. you still have a mechanical parking brake with any rear disc kit based on factory parts no matter which one you choose so that shouldn't be a factor in the decision, IMO, the only thing that should have a bearing on that would be whether or not you pull a boat and intend to get the parking brakes very wet, because disc style parking brakes tend to not hold AS well as a drum style parking brake when submerged in water, at least that has been my experience anyway.

 

[66Runt]

If using the stock pull type P-brake handle, then care needs to be taken to make sure everything is setup correctly when running SN-95 rear discs.
The tunnel parking brake has much higher leverage, than the original first generation pull type.
Where this comes into play is if the rear brakes are hot when you apply the P-brake. As the vented rotor cools it shrinks, and lessens the holding power.
On my '66 I did some extensive testing on grades at different temps, and found that once everything was cleaned, lubricated and properly aligned-adjusted, it has excellent holding power, even when applied at over 500*F, on a steep grade, and allowed to cool to an ambient temp of 70*F.
My first tests without cleaning, lubricating and aligning everything just right were failures. Enough that I was originally concerned about this, and seriously considered installing a foot operated P-brake (wanted to keep the stock console).
edit************
I have the Cobra discs all the way around. Pictures are on the web site in my signature.

 

[Rusty67]

Ultrastang, I'm not at all worried about failure. My daily driver for the last several years has been a 2000 v6 Mustang and I've never had the parking brake fail on me either and that is with well over 100,000 miles on them. The reason I don't like those rear calipers is simple. They are stupid. It is a dumb design and you don't get the added benifit of a second friction surface. Infact, I dislike them so much that I was thinking of changing out to the CV brakes but I ended up buying the Cobra upgrade kit for them so I could have a vented rotor. I searched high and low and the only way I was able to get a vented rotor for that setup was to step up to the Cobra setup.

 

[ultrastang]

my ONLY issues with the C-V brakes are the solid rotors and the clocking of the calipers, one side is in front of the axle centerline and the other is behind it. not sure if the 03 up are this way too, but at this point it may be a moot point since the housing flanges are sideways and won't bolt up directly to a mustang rear anyway. there are however aftermarket vented rotors available for the C-V brakes so that takes that issue out of play and only leaves the goofy clocking of the calipers. i don't believe the explorers have the goofy clocking issue.

i also prefer the internal drum parking brake BUT only because i'll pulling a small boat behind the cougar on occassion and prefer the drum style parking brake on boat ramps. if it wasn't for that fact i wouldn't sweat the internal drum parking brake AT ALL.

i'm also fairly certain there aftermarket vented rotors available for the sn-95 brakes as well you just have to do a little searching.

for those who may be interested in an internal drum parking brake style setup i noticed that Heidts has a setup that uses what "appears" to be a wilwood backing plate and drum style parking brake kit that uses a GM style caliper with a vented rotor that looks like it could be a viable option for a little less than a typical aftermarket rear disc kit (about $600) there is also the vintage venom kit as well, http://www.vintagevenom.com/mustang-rear-disc-brake-conversion-kit.htm, but this kit is apparently not the same as their old rear disc kit that had vented rotors, not sure what's up with that though.

like i said, if it wasn't for that fact that i'll be pulling a boat with my cougar i'd use one ultrastangs rear disc kits and save a bunch of money over an aftermarket kit. that's my opinion so take it for what it's worth but i think that 98% of street cars will work just fine with one of ultrastangs rear disc kits vs the internal drum brakes. you still have a mechanical parking brake with any rear disc kit based on factory parts no matter which one you choose so that shouldn't be a factor in the decision, IMO, the only thing that should have a bearing on that would be whether or not you pull a boat and intend to get the parking brakes very wet, because disc style parking brakes tend to not hold AS well as a drum style parking brake when submerged in water, at least that has been my experience anyway.

The '92-'02 C-V calipers are mounted with the passenger's side caliper in front of the axle and the driver's side is behind the axle. On the '03-up version, the calipers mount on the same side of the axle housing, but the angle the parking brake cables go into the parking levers is not the same as earlier versions, and the angle of actuation on the parking mechanisms is not the same either.

I have a customer from Alabama, who posts here and on VMF, that goes by the board name "L-Man". He has a '68 track car he's building. He bought a set of brackets from me to install the SN95 V6/GT rear discs on his race car. Since he's not going to be running a splash shield, he fabricated an air duct that will attach to the splash shield's pickup points on the adapter bracket to mount the duct to. He's hoping that with additional forced flow across the rotor, that the solid rotor will be ok. I guess we won't find out until this spring when his car is finished and he can get some lap time on the track to see how it holds up...

I know you & I have discussed the holding power of the integral vs. drum-type parking brakes before, and that your concern is wet brakes not holding with the integral type. I guess I should perform a simple test on my '03 Mach 1, by soaking the rear brakes down and then see if the car will move when the rear brakes are wet and the parking brake set. My Mach came from the factory with a Tremec 3650 with a 3.38:1 1st gear ratio and factory 3.55s in the rear with a Traction-Lok. That combined would be a power multiplication factor ratio of 11.999:1 (or 12:1) [3.38 1st gear ratio x 3.55 rear end ratio] --VERY strong pull in 1st gear. --But, I'm on 12 hour graveyard shifts for the next week and a half, so that experiment will have to wait.

 

[ultrastang]

Ultrastang, I'm not at all worried about failure. My daily driver for the last several years has been a 2000 v6 Mustang and I've never had the parking brake fail on me either and that is with well over 100,000 miles on them. The reason I don't like those rear calipers is simple. They are stupid. It is a dumb design and you don't get the added benifit of a second friction surface. Infact, I dislike them so much that I was thinking of changing out to the CV brakes but I ended up buying the Cobra upgrade kit for them so I could have a vented rotor. I searched high and low and the only way I was able to get a vented rotor for that setup was to step up to the Cobra setup.

I under stand what you're saying. I guess I wasn't really talking about mechanical failure of the SN95 caliper, but rather that I've never had a problem with it holding the car when applied. I set the parking brake every time I park the car (hill or not), and from time-to-time, I have a "doofus moment" and forget to release the parking brake before trying to start off. Even as powerful as the Mach 1 is, the car won't budge an inch when the parking brake is set.

 

[bnickel]

I under stand what you're saying. I guess I wasn't really talking about mechanical failure of the SN95 caliper, but rather that I've never had a problem with it holding the car when applied. I set the parking brake every time I park the car (hill or not), and from time-to-time, I have a "doofus moment" and forget to release the parking brake before trying to start off. Even as powerful as the Mach 1 is, the car won't budge an inch when the parking brake is set.

well, until you put a boat on the back of it and stick it in a lake i won't be satisfied if i were going to keep the stang then i'd put a set of cobra or mkvii brakes on it and but the kit from you since i'd never even consider pulling a boat with the stang but the cougar's a little different story.

 

[Helmantel]

The reason I don't like those rear calipers is simple. They are stupid. It is a dumb design and you don't get the added benifit of a second friction surface.

I'm not sure what you mean? Why do you think they don't have a second friction surface? As far as I know, it's a floating caliper, just like most others.

 

[Helmantel]

Another thing to consider when choosing rear brakes is the front brakes you have. For example, MkVII rear brakes have ~ twice the (theoretical) capacity of SN95 rear brakes, due to their much bigger caliper pistons (2.125" vs. 1.50") and slightly larger rotors (11.3 vs. 10.5). Of course, that's a theoretical value, assuming the same line pressure and pad friction, but something to keep in mind.

Front/rear brake bias would of course be quite different for the two setups. Brake bias can be fine tuned with an adjustable proportioning valve, but it's best to have a decent match of the front and rear hardware to begin with and fine tune from there.

 

[Decurion]

Thanks guys! From what everyone said, it sounds like I was right all along to go with the C-V setup. Im really not too concerned about the parking brake since I never use it, and for now its still an automatic so its really a non-issue anyway.
I guess I was looking for 2 things that didnt really seem to get explained. 1) Whats the benefit to reclocking one side of the CV brakes? Looks? and 2) Is the Mark setup a near bolt on like the others? Keep in mind its a station wagon so it can handle more rear brake bias than most other cars. Im sure Im WAY overthinking this, but hey, Ive got the time (and no money to do the swap just yet, but soon) so I may as well figure out what will be best, since theyll all cost the same.

 

[Rusty67]

The reason for the funny clocking on the calipers is not for looks, it is for saving money. They didn't have to have a drivers/passenger side set of parts, its the same set of parts turned around. Less unique parts equals cheaper to buy because you are buying 2x as many similar parts and can get a better price brake because of it.

Helmantel, what I mean by two seperate fiction surfaces is that there is a drum inside the rotor and the rotor itself. I know there are pads on both sides of the rotor. Inside the hat of the CV rotors are a smaller drum with seperate brake shoes which act as the parking brake and if the calipers fail (not likely but it COULD happen) then you still have your parking brake AND a seperate set of friction material.

 

[LMan]

Well! Long time, no type

As Steve says, I will be pleased to report to all on how the SN-95 rear disc setup works on the track at Road Atlanta in March. I personally feel the vented/non-vented rotor concept is overblown for rear discs....considering how little braking they do compared to the fronts. But that's just my feeling. For now.


If I am wrong, I will have no problem confessing here and getting a deserved verbal azzchewing from yall

 

[bnickel]

Thanks guys! From what everyone said, it sounds like I was right all along to go with the C-V setup. Im really not too concerned about the parking brake since I never use it, and for now its still an automatic so its really a non-issue anyway.
I guess I was looking for 2 things that didnt really seem to get explained. 1) Whats the benefit to reclocking one side of the CV brakes? Looks? and 2) Is the Mark setup a near bolt on like the others? Keep in mind its a station wagon so it can handle more rear brake bias than most other cars. Im sure Im WAY overthinking this, but hey, Ive got the time (and no money to do the swap just yet, but soon) so I may as well figure out what will be best, since theyll all cost the same.

IMO, as long as you're not pulling a boat the drum style parking brake isn't really necessary. you'll notice that these type of systems mostly come on big cars and trucks and that's because they could possibly use these for towing a boat. mustangs and other performance or smaller sports type cars don't have the drum style parking brake.

BTW, Decurion did you see the newest issue of car craft with the comet wagon? cool

 

[ultrastang]

Thanks guys! From what everyone said, it sounds like I was right all along to go with the C-V setup. Im really not too concerned about the parking brake since I never use it, and for now its still an automatic so its really a non-issue anyway.
I guess I was looking for 2 things that didnt really seem to get explained. 1) Whats the benefit to reclocking one side of the CV brakes? Looks? and 2) Is the Mark setup a near bolt on like the others? Keep in mind its a station wagon so it can handle more rear brake bias than most other cars. Im sure Im WAY overthinking this, but hey, Ive got the time (and no money to do the swap just yet, but soon) so I may as well figure out what will be best, since theyll all cost the same.

1. "Clocking" refers to the postion of the caliper in relation to the the rotor/axle housing --such as the more common 10:00 o'clock/2:00 o'clock mounting postions of most calipers. I'm guessing what you're meaning by "clocking" is swapping sides with the C-V brake assemblies? If this is what you're saying, it won't matter what side you move the assemblies to, you'll still have one in front and one in back of the axle housing. The only way that senario would work is if the C-V actually had a "left" and "right" side.

If you tried to flip the anchor bracket over to bolt up to the housing's end flange from the face side of the anchor bracket instead of the back side, you would push the caliper out past the rotor so that they would be in two different planes and wouldn't line up.

2. To my knowledge, I'm the only one that sells a conversion bracket to adapt the Mk VII rear discs to a Ford 8- or 9-inch rear end housing. It would be possible to Install the Mk VII setup without my adapter brackets, but this is going to mean a lot more work because you would have to modify the factory stamped steel brackets to fit, then you would have to weld the the stamped steel brackets to the axle tubes. My solution is a bolt-on that's pretty easy on/easy off --if you decided to go with some other rear brake setup later on. The other alternative is not easily undone.

I guess it would be biased for me to say the Mk VII conversion has been a good setup. So, here's a link to a customer from Texas that posts on various Mustang boards under the name "JamesW". He devoted two pages of his own website for the Ultrastang Mk VII rear disc conversion: http://www.midnightdsigns.com/Mustang/Rear_Brakes.htm