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I've been poking around with this project since the start of the covid lockdown, just kind of puttering around in an attempt to keep myself busy, you know? Well, I finally finished it, so thought I would do my normal writeup with install details, thoughts, motivation, yada yada. I'll break it down into three posts for better clarity. First post will be summary of parts, motivation, and thoughts; second post will be actual install details for the rear discs; third post will be details for the rest of the overhaul, plus a wrap-up.

So here goes:

WHAT MY ORIGINAL SETUP WAS:
  • Kelsey Hayes stock front disc brakes (which I later found out were using 1967 calipers - more on that later)
  • 11x2" rear drum brakes that matched the 1956 Fairline (or large station wagon equivalent) rear end that I have installed
  • 9" big bearing rear end (out of 1956 Fairlane or equivalent large station wagon)
  • Stock-style flex brake lines on front and rear body-to-axle
  • 1974 Maverick dual bowl master cylinder w/ stock pushrod
  • Wilwood proportioning valve
  • Stock (original) brake lines
  • Lokar center-mounted parking brake
WHY I WANTED TO SWAP TO REAR DISCS:
I had a number of issues with the braking system that I wanted to address:
1) The pedal was not rock solid. It was always a little squishy, pointing towards either a bad master cylinder, or a continually leaking wheel cylinder. The rear drum brake wheel cylinders went bad a few times over the past few years - poor manufacturing with bleeder screws with improperly machined threads bleeding air/fluid, seals blowing out, etc. Flex brake hoses could also have contributed, but I didn't think that they would be giving me that bad of a pedal feel considering their age. At the time that I decided to do this overhaul, the wheel cylinders did not appear to be leaking, pointing towards a bad MC, but I also don't trust the wheel cylinders anymore after having multiple failures over the past few years. I used Wagner wheel cylinders. QC issues might be a brand-wide issue, or they might be because I have an obscure brake size.
2) The drum brakes were grabby. The rear brakes were very prone to locking up, even with adjustments to the prop valve to reduce pressure to the rear. They would work fine and then grab really hard once they reached whatever their critical point was. Pad availability for an 11x2" brake is zilch, so I would have needed custom pads built for the shoes to possibly mitigate this problem.
3) I dislike drum brakes in general. They are fine for an average puttering-about-town fair weather driver. They are not fine for a car like Jane. They (at least mine) operate inconsistently, grabbing at weird times and other times doing very little, especially when wet. I could not reliably stop the same way in all weather conditions, which is bad because I drive in dry weather, hot weather, monsoon conditions, heavy traffic, etc. It's not safe to have to do mental calculations about your stopping distance vs pedal effort vs potential for locking the brakes or hitting someone, at a point when you are trying to do an emergency stop. I need to be able to just slam on the brakes and stop, no questions asked. Also, I just hate servicing those damn things.
4) I was bored and had money burning a hole in my pocket.

WHAT I BOUGHT:
  • Wilwood Dynapro low profile rear disc brakes with internal drum parking brake, for a 9" big bearing rear end, P/N 140-11387 ($650 Amazon)
  • Wilwood -3AN 14" stainless steel braided flex brake hoses, P/N 220-7056 ($60 Summiit)
  • Classic Tube direct-fit stainless steel braided flex brake line hose kit for front / rear body-to-axle, single exhaust car, P/N SBH6305 ($135 NPD)*
  • Lokar parking brake cable clevis kit, P/N EC-81FC ($41 Summit)
  • Raybestos 1974 Maverick master cylinder, P/N MC36440 ($36 RockAuto)
  • Scott Drake adjustable brake pushrod, P/N A21161 ($42 NPD)
  • Prestone DOT3 brake fluid, 1 bottle
  • (1) 3/16 steel brake line, 8" long ($3 OReilly's)
  • (1) 3/16 steel brake line, 30" long ($4 OReilly's)
WHY I BOUGHT WHAT I BOUGHT:
  • Wilwoods: Verified to fit under the 15" styled steel wheels, which have a lip on them that interferes with most calipers. Not big brakes, but then again I don't need big brakes on a fastback with a very light rear. Has an internal hat drum style parking brake which separates parking brake adjustment from the rest of the brakes, meaning that I don't have to finagle with setting it at the perfect amount of drag - just whatever will hold the car with the parking brake on. Found a big discount on the Wilwoods through Amazon which helped, and Wilwoods are a well-known name with highly engineered products which guarantees that I won't have to "convince" parts to fit or do any modifications.
  • Wilwood brake hoses: I could have made my own for cheap using Summit branded brake line and fittings. But I really am not in the mood to save a few bucks on a part that is necessary to keep me from hitting things. Top of the line machine-made and tested is the way to go.
  • Classic Tube brake hoses: Same reason as above. I just wanted something that would be a perfect factory plug and play. Although I have a dual exhaust car, I actually use the single exhaust hoses (which are, annoyingly, $35 more expensive for some reason...) because the mounting point on my axle is different from the mounting point on a normal Mustang axle (remember, home-grown 1956 big bearing rear end, not Mustang rear end). I later learned that the calipers on my supposedly 1966 Mustang KH disc brakes are for a 1967 Mustang, which uses 7/16" ports instead of 3/8" ports. I learned that you cannot adapt the 3/8" lines to a 7/16" line using a Dorman part, as it will leak like hell and then you'll pull the threads out of the fitting anyways. So I ended up having to change out to the Classic Tube kit for a '67 Mustang (SBH6087) to get the front lines correct, and used the single exhaust hose from the '66 kit. I'll sell the other kit as a '66 dual exhaust kit, since that's what it is now (two leftover 3/8" port front lines, plus one rear line with the dual exhaust bracket as used in 66/67).
  • Lokar clevis kit: This was the part that made me the most mad to buy. It's just two little brackets, and $40 is way overcharging for them! But I needed them to convert my Lokar parking brake cables to something that could be used by the Wilwood parking drum mechanism. More on that later.
  • New master cylinder: I didn't know if the old master cylinder was bad or not. It was $36 and I would rather pay that than go through this whole install, try to bleed everything, then find out that the master cylinder is also a problem and have to install a new one and then bleed the whole system AGAIN. I really hate bleeding brakes.
  • Adjustable brake pushrod: I don't think that ultimately this was really a necessary investment, as it turns out that I kind of got used to my pedal being where it was, so I ended up adjusting the pushrod to put it back there. But originally the idea was to allow me to put the pedal a bit closer to the floor, which would give more leverage over less pedal throw, and also be a little more ergonomic. I don't regret the buy as I can still fine-tune it for that. But it wasn't necessary.
  • Steel brake lines: I wanted to make shorter brake lines so that the flex lines used to attach the rear calipers to the rear brake lines wouldn't be all bunched up under the frame in a weird way. Just a few bucks for a cleaner, better-thought-out install.
Skipping forward to the review part, and then I'll go into the install in the next post.

WHAT I GOT OUT OF THIS INSTALL:
1) An overhauled brake system with minimal space for "slop" that would lead to pedal squishiness: SS hoses, which mitigate brake hose ballooning; new MC, in case the old one had bad seals; new brake pushrod, allowing better pedal adjustment to make sure there was not "dead space" at the top of pedal travel; eliminated wheel cylinders that had consistent QC issues.
2) DRASTICALLY improved pedal feel. It FINALLY feels like a manual brake pedal should, with no squishiness.
3) DRASTICALLY improved braking consistency. The new discs don't grab and lock like the drum brakes did. Consequently, now I don't lock up the rears and slide when I slam on the brakes, AND I was able to actually add bias into the rear circuit for less nose-diving (caused by too much front brake bias) without having to worry about flipping the car 180* when the rear brakes would inevitably lock up. So the car now stops significantly better, and doesn't dive forward due to relying mostly on the front brakes.
4) Retained parking brake functionality (already had a very nicely-functioning parking brake to begin with) that has no trouble holding the car on a slope, even out of gear
5) Finally, a god dang good braking system.

WHAT I LOST FROM THIS INSTALL:
1) Money (just shy of $1000)
2) Drum brakes

WHAT I WISH I HAD GOTTEN OUT OF THIS INSTALL, WHICH I DIDN'T GET:
1) Absolutely nothing. This overhaul achieved everything I was looking to achieve and I got everything I wanted.
 

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Discussion Starter #2
Ok! Down to the install. This one won’t be incredibly detailed just because Wilwood already provides pretty great instructions. I actually installed the kit in probably a couple of hours flat, but then spent many days screwing around with making things perfect.

So, step one was to pull off all of the old junk. I disconnected the rear brake lines and pulled off the drums and hardware. I also went ahead and disconnected the front flex lines and pulled the master cylinder, since I was going to be replacing all of those. I put caps on the ends of the brake lines because I’m paranoid about bugs and stuff getting into them.

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The next step was to remove the old factory bearing retainer plates. They are sandwiched onto the axle between the axle hub and the axle bearing, and so need to be cut off. I wrapped a bunch of rags around the bearing and hub surfaces, taped it all up, and then used a Dremel with a cutoff wheel to do the job. I initially tried a jigsaw that I had laying around, but that had a 0% chance of working. A Dremel took care of things very quickly.

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After that, I installed the parking brake drum assembly onto the axle as directed by the instructions. The pads/hardware faces outward towards the wheel. You just slip the assembly (which comes already assembled in the box) over the axle, then install the axle back into the housing. From there, you use the stock bolts that originally held the drum backing plate, to position and hold the new parking brake assembly.

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Now, whether or not the next part sucks is entirely dependent on your axle hub, apparently. Some are smaller. Mine is huge, and roughly the diameter of the parking brake assembly. This is annoying because you have to slide the new U-shaped bearing retainer up into the parking brake assembly to be held in place by the 4 bolts (basically sandwiching the end of the axle between the parking brake assembly and the bearing retainer plate), but if the hub is large and doesn’t stick out that far, you kind of have to do some fishing around in the gaps to get everything positioned right. Once the pieces are positioned correctly on the bolts, you have to attach the nuts (which you will drop into the depths of the parking brake housing at least 3000 times) and torque to spec.

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I found that in my case, the rubber plug for the drum adjuster was interfering with the axle flange, causing the assembly to not mount up flush. I just pulled the plug out and left it out, which I’m sure will be fine. But make sure you check for this if you are installing the same kit.

After that, you need to test fit the rotor and caliper. Slide the rotor over the hub and hold it on with a few lug nuts, finger tight. Then place the caliper on the rotor.

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Wilwood recommends that you start with two shims (washers, included) per caliper bolt between the caliper and the caliper mounting bracket (attached to the parking brake assembly). You use the shims to adjust the positioning of the caliper relative to the rotor, obviously with the goal of centering the rotor within the caliper. Let me tell you, it is a PITA to get the calipers bolted up without the shims falling out as you’re trying to thread the bolt through. I thought about “tacking” them in place with some grease, but was afraid the grease would later get on the rotors, so I opted not to do that.

759312


I ended up needing 3 shims to center my calipers correctly, instead of the 2 that Wilwood recommends to start. No big deal. If you need more than 3 shims, you will need to go out and find longer caliper bolts to ensure that they properly engage the “clinch nuts” in the bracket. With 3 shims, the bolts provided in the kit are just barely long enough. They’re fine thread automotive grade, but you can get them at any auto parts store. Annoyingly, they come in packs of 3, so you’ll have to buy 2 packs to get the 4 bolts that you need.

Once you’ve figured out the caliper adjustment, the next critical part is to install your wheels and MAKE SURE EVERYTHING FITS. The wheels have to clear the calipers, obviously. But you also need to make sure that your wheel studs are long enough. Another word of warning: the Wilwood rotors are machined with holes exactly the size of the wheel stud threads, so if your wheel studs have a shoulder on them that sticks through the hub, it will prevent the rotor from seating correctly. Don’t let this happen! I ended up getting new wheel studs with a shorter shoulder that didn’t stick through the hub, which solved that issue for me. Others have solved the issue by drilling the rotors out to a wider diameter to slip over the shoulders. I didn’t trust myself to drill a hole straight (no drill press) which is why I went with different wheel studs.

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I verified that my wheel cleared the caliper and all other brake parts fine, and made sure that the wheel studs were long enough to engage enough of the lug nuts. I measured 8 full turns to tight, which is somewhere between ½” and 5/8” engagement. Bueno. A nice thing about this kit is that it doesn’t change the track width of your car (0” offset), so the tires should sit in exactly the same place as they did before. Thus, I did not need to check to make sure the wheels cleared the body.

759314


Oh, and another pro tip: when installing wheel studs, it helps a lot to sandwich a bearing in there (as shown on my picture). What I do is place the wheel stud in the hub, slide a bearing over top of it, put a big washer over top of that, and then add a sacrificial junk nut to the end. You can then get things started with a ratchet and finish yanking them in with an impact. The bearing reduces the friction needed to turn the nut, which makes installation much quicker and prevents you from jacking up the nut / surface of the hub.

I pulled the wheels back off and proceeded with the rest of the install. First was putting the brake pads into the calipers, and doing final install of those. Wilwood specs red Loctite for the caliper bolts. Well, I did the left hand side with red Loctite, then got really paranoid that I would need to remove the caliper for some reason in the future and would have a bear of a time with that stuff, so I did the right hand side with blue Loctite (which is slightly more removable than red). I’m sure this will make me really, really angry in the future. Whatever, sounds like a problem for future Kelly. I torqued to spec and did my best to forget about it.

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(Pic: me holding red Loctite in front of the brake that I put it on, so I can find this photo later in the future and be angry but at least know what happened)

----(I guess even though the new site makes it a million times easier to put photos inline with the text, it still caps them at 10, so next post to be continued...)----
 

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----(Continuation of rear disc installation post)----

From there, I installed the right-angle NPT fittings (provided in the Wilwood brake hose kit) into the calipers. It kind of bugs me that they use NPT fittings instead of –AN or inverted flare fittings. But whatever. I cranked those suckers down and then loosely installed the -3AN brake lines so that I could play around with routing. Of course, I later forgot to tighten these and brake fluid went absolutely everywhere. C’est la vie.

Since I was also making new hard brake lines for the axle, I had the opportunity to route things exactly how I wanted. The most important thing is to avoid any place where the line can be crushed – so you need to route the flex lines around the axle stop, but also not go too close to the frame. Easy peasy.

Before doing the new hard lines for the rear end, I installed the flex line that goes from the body to the axle. My car has some crazy 1956 9” big bearing axle in the rear, which means that the mounting point for the end of the brake line is in a weird (but much more convenient) place compared to the Mustang axles. My mounting point is almost butted up to the pumpkin, allowing to keep all of my lines inboard of the exhaust. This is why I use a single exhaust hose, even though I have a dual exhaust car. Because the hose runs so close to the pumpkin though, I opted to cobble together a little bracket to hold it so it wouldn’t chafe over time.

759316

(My exhaust looks like garbage because it is garbage... it's a unique combination of poor quality, partial wreck destruction (got bent up and we just yanked it out straightish), and continued general destruction (I routinely smash it on the trunk floor going a thousand miles an hour through potholes or offroading or whatever))

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Once that was installed, I measured the length of the old brake lines and subtracted roughly 6”, then went to get some new line to bend (I ended up getting an 8” long piece and a 30” long piece but of course that’s not useful information to anyone with a typical Mustang axle). It was pretty easy to just bend the new lines to roughly match the curvature of the old lines. I had them stop a little short and kind of angle off to the side of the axle at the distal ends, which allowed me to attach the -3AN flex lines without any kinking. Again, surprisingly easy.

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At this point what should have happened is I should have tightened all of the brake line fittings, but instead I forgot and left them to leak horrifically when I went to bleed the brakes. So if you’re installing discs on your car, maybe don’t leave that step out.

With the brake lines set up, the next step was to hook up the parking brake. I have a Lokar center-mounted parking brake with the corresponding Lokar cables, which of course have a simple ball end for mounting to drum brakes, and not the fancy hooked end that Wilwood wants you to have. You can solve this problem by buying Wilwood parking brake cables (ughhhh, $$$$) or you can buy this clevis kit that allows you to adapt your ball-ended parking brake cables to have the correct hook on the end to work with the Wilwood parking brake (ughhhh, $$). The clevis kit is 40 bucks and it’s definitely not worth that price, except for the fact that it kept me from having to buy the much more expensive Wilwood cables. So, whatever. But probably if you were really determined to save some money, you could make your own and it would work just as well. The important thing really is that you can hook the parking brake cable onto the hook mechanism, and who cares how you accomplish that.

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This caused my parking brake cables to be too long, and they were too long anyways to begin with. I took the opportunity to “fab” up some brackets to hold the parking brake cables more securely (read: I repurposed some pipe straps from Lowes and attached them to random bolts that were already sticking out of the body) and re-routed them to contour more smoothly to the body without interfering with stuff. You don’t want a sharp bend in the cables, and you also don’t want the cables to be hanging out near the driveshaft… which is what mine did previously (I had zip tied them up out of the way).

With the cables properly routed, I had about 8” too much length on the parking brake side of things, so I cut the cables (both sheathing and wire) to the correct cable length. Then I pulled the wire out of the sheathing a couple feet, and cut the sheathing to the correct length for the assembly. I used my scary stainless steel hose chompers for this task, though a dremel would also work. Stuck the cable and sheathing in the correct places, and that task was finished. Easy peasy!

The parking brake is adjusted the same way you would normally adjust a drum, using a screwdriver stuck through the back to turn a star adjuster wheel. Conveniently, on Wilwoods the stars are set up the same on both sides so that up always adjusts narrower, and down always adjusts wider (or vice versa, I kind of forget by this point). I found that the shoes were not correctly centered to begin with, so I had to adjust them as wide as possible, and then back off the adjusters until they just barely dragged but still stopped the disc when the parking brake was pulled. Had I realized this earlier on in the install, I would have adjusted the drums most of the way to fit the rotors before I had installed the rotors completely, because it would have been easier to just pull the rotor off and spin the star wheel by hand rather than fishing around with a screwdriver. Alas, I wasn’t that smart, and the red Loctite on my lefthand brake dissuaded me from trying to diassemble the rotor and caliper again to speed the process up. At any rate, I discovered that it was far easier to access the star from the front face of the brake (there’s a big hole in the hub, so you can fish a screwdriver in through the hole in the rotor as it overlies the hub hole) so adjustment was not a huge pain. Adjusting from the inboard side through the slit intended for adjustment would have been a PITA, because as you may remember, the flange of my axle tube was partially covering that hole.

I tested the parking brake a few times until I had it adjusted the way I liked. Fortunately, my cables are already pre-stretched, so the first adjustment is the only one I had to do. But if you have new cables, you’ll need to adjust the cable wire length a few times as they stretch.

And that concludes the rear disc installation, I guess!
 

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To complete the overhaul, I swapped out the old flex hoses on the front discs for a pair of stainless steel braided flex hoses from Classic Tube. The hoses are VERY nice and are made to be direct fits into the stock Kelsey Hayes calipers, so you don’t have to go boogering around trying to convert an AN hose into an inverted flare fitting. You sure do pay for them though.

There are a couple of things that I learned from doing that swap. First of all, when I installed these discs ten years ago, they were spec’d as 1966 stock Kelsey Hayes discs. I learned during this install that the calipers were 1967 calipers (which use a 7/16” port instead of a 3/8” port as the ’66 calipers do). I don’t know if all reman/aftermarket calipers are just swapped to the 7/16” port size, or if something just kind of got screwed up in the box there ten years ago. Either way, check to make sure of your port size!

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Which brings me to the second thing I learned: the Dorman Help! Brand brake line adapters are NOT up to the task of adapting the 3/8” hose to the 7/16” caliper inlet. First of all, they don’t seat right in the caliper for some reason, and leak like crazy. Second of all, when you try to crank down on them to make them seal, the threads will rip out of them. Fortunately my nice expensive hoses were not ruined, just the adapters. Garbage quality part, and who knows why they didn’t want to seal. I think that the threaded portion wasn’t long enough, so the fitting collar bottomed out on the caliper before the flared end sealed. Whatever. Don’t use it. Use hoses that fit to begin with, or use adapters from an actual quality car parts shop (Summit or equivalent).

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What I ended up doing was ordering the 1967 brake hose kit as well. I needed to use the single exhaust hose from the 1966 kit for the body-to-axle connection, and the two front hoses from the 1967 kit for the front brakes. I was left with two front hoses for a 1966, and a dual exhaust hose for a 1967 (which I believe is the same as a 1966 dual exhaust hose). So I’ll just sell that kit somewhere to recoup some of the cost.

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Once I had sorted out the brake lines, I bench bled the new master cylinder on my nice new vise! I got it for my birthday and it’s the first vise I’ve ever had. No more wedging parts on the floor and smashing my hands repeatedly to tighten things! Yay.

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I installed the adjustable pushrod into the MC after making it roughly the same length as the old pushrod, which I figured was a fine starting place. Then I stuck the MC in and attached the pushrod, lines, etc. You guys know the drill.

I then bled the brakes, like three times before finding all of the insidious leaks. Actually, the first time the leaks weren’t insidious, they were prolific because I forgot to tighten all of the AN connections on the rear hoses. The second time I missed a very tiny weep from the rear body to flex line, which I found out was due to the way the line was angling into the fitting. I bent the line a little and that sorted itself out too. And now, for the first time in YEARS, I can bleed my rear brakes and they come consistently clean with no bubbles!! Amazing.

The final step was to adjust the brake pedal to my desired height. Originally I thought that it would be great to have the pedal a little lower, to put it more in line with the gas pedal. That turned out to be a bad idea because doing that is accomplished by reducing the length of the pushrod, which gives you less leverage and less swing. So I adjusted it back up to the stock length. I might adjust it a little higher. But really, the adjustable pushrod was probably not necessary.

Let me tell you, the first lap around the block was AMAZING. I monkeyed around with the proportioning valve a little bit until I had great stopping power with no side skittering and no nose diving. It’s weird because I can stop much more quickly than I did before, but I also have a much harder time locking up the brakes. I think that that’s because the drums were so grabby before – the working hypothesis was that they would get to a certain point, stop the rear wheels dead, and then I would just slide forward on whatever braking power I could get from the front wheels. The drums never did show signs of flipping me around 180* (as is rumored to be a big problem with Mustangs) but that may be attributable to the suspension modifications I’ve done, which limit sideways or uneven suspension deflection which would initiate the turn-in and subsequent tail-swapping.

I found it interesting that I actually had to increase the amount of fluid flow to the new rear brakes to get the bias right. Previously, the car would nose-dive pretty hard even as the rear wheels locked up. With the prop valve opened up a little more and the rear discs installed, I can get a very even heads-up stop without any squirreliness. It inspires a lot more confidence, that’s for sure!

So there you have it folks. Whatever the problem was originally – just garbage rear drums, or a bad master cylinder – it is now solved, and braking is a million billion times better than it ever has been.

Oh, and I rebuilt my shifter too “while I was at it” and now I miss shifts all the time because the shifter is now precise and requires more effort at precision from me than I was used to giving. Previously, shifting was kind of like lobbing a stick down a hallway – no way you could miss the shift! Oh well, I’m sure I’ll wear it in again in no time.
 

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Wow! Thanks for the write-up. One of my future projects is a rear disc swap and this answered questions I hadn't even thought of asking (y)
 

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Very nice write up Kelly, very descriptive, which is good for a write up. :)

When you put the Wilwood rear discs on did you notice any additional offset?
 

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4) I was bored and had money burning a hole in my pocket.
Nice write up! But next time, save your pants and just send the money to me to burn a hole in MY pocket! ha ha
 

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Excellent write up, thanks for sharing Kelly.
 

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  • Wilwood Dynapro low profile rear disc brakes with internal drum parking brake, for a 9" big bearing rear end, P/N 140-11387 ($650 Amazon)
Great writeup, as always a pleasure to read.
Kelly, I've tried to figure out the various Wilwood products. I think I counted over 40 different calipers. Why did you choose the Dynapro low profile version?
 

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I’m going the other way on this, I was all set to stick with my rear drums and now I’m undecided. Thanks a lot Hattori...
 

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Nice write up Kelly. I like the "little drum" parking brake over the wind back for sure. Have you tested your E/parking brakes effectiveness at speed? I assume the thickness of the rotors vs drums moved the wheels out a 1/4"-5/16" per side?
 

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Very nice write up Kelly, very descriptive, which is good for a write up. :)

When you put the Wilwood rear discs on did you notice any additional offset?
Nope, this kit is specifically spec'd to have zero change in offset. That's why I bought it - my tires/wheels are tucked in just about perfectly and I'd like to keep them that way, thank you very much.

Great writeup, as always a pleasure to read.
Kelly, I've tried to figure out the various Wilwood products. I think I counted over 40 different calipers. Why did you choose the Dynapro low profile version?
There are a lot of different products, but they've got 4 or 5 main "lines", with a kit for each bearing type (small bearing, big bearing, Torino, etc.) and a bunch of different small variations (plain/drilled/slotted rotors, undrilled hubs, dust shields, caliper configuration, etc.). I figured I needed the smallest disc possible for two reasons: (1) the 15" styled steel wheels that I run have a lip on the inside that interferes with the caliper on most larger brakes; and (2) the rear end of a fastback Mustang is very light, and you need to dial back braking capability even on small drums to avoid flipping tail-out, so I figured I didn't need colossal brakes back there anyways. The smallest rotor possible was 11".

Of the 11" brakes available, there are three options - all the same line (Dynapro), just three variants. One has undrilled rotor hubs, one has dust seals for an additional 50 bucks, and the other one is "standard" with rotors you can plop on your car right away, and no dust seal. So the "standard" one is the one I bought.

If I had bigger brakes in the front, maybe I would have gotten bigger brakes for the rear as well. But I don't, I have stock KH brakes up front, and I have 15" wheels that prevent me from upsizing anyways.

I’m going the other way on this, I was all set to stick with my rear drums and now I’m undecided. Thanks a lot Hattori...
Ha! Well, if your rear drums function RIGHT, then probably they are not a problem. My brakes did not function right and were dangerous and grabby, so I remedied the situation. Since I've never had a car with the "standard" Mustang drums (mine were 11x2" monstrosities), I have no way of knowing whether the normal drums are fine or not. But the discs are really great.

Nice write up Kelly. I like the "little drum" parking brake over the wind back for sure. Have you tested your E/parking brakes effectiveness at speed? I assume the thickness of the rotors vs drums moved the wheels out a 1/4"-5/16" per side?
Hmm, nope, haven't tested the parking brake effectiveness at speed, nor is it really a priority - we all know that stopping the rear wheels is the best way to get a Mustang tail-happy! If I need to "whoa" fast, the manual transmission will do a much better job than a parking brake ever would. I know this because early on when I first installed that center mounted parking brake (with the old drums), I would forget about the parking brake and drive around with the brake on ALL THE TIME. Never really noticed except that the brakes would be smoking when I got out of the car later. So I have to assume that the parking brake was never really very effective at stopping the Jane Train anyways.

There is no change in offset between the rotors and the drums, as the rotors are the same thickness as the drums.
 

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Your new setup looks pretty cool! That mini drum parking brake is neat. I finally got my stupid Versailles junk sorted out to the point of not leaking but still have an inoperative parking brake. At least it stops better though. At some point I am going to toss all this Lincoln junk in the garbage where it belongs. I'm still pondering options for what to swap to and was looking at Mustang Steve's Cobra rear brake kit since it says it fits most 15" wheels (unsure it if fits Mag 500s), but this sounds like it may be the ticket.

I want to find something that will still fit my 15" Magnums or maybe some 16" wheels later on. That is great that they don't change offset. With the Versailles my tires are slightly farther out already. I've always had my brake pedal adjusted to about the same height as the clutch pedal, just not a fan of having it lower. It seems to be just the right spot with manual brakes.

I generally hate drum brakes too, both working on them and their operation. They seem to work fine in the rear of all the Ford trucks that I've had, but they never worked very good on my car when it had all the I6 stuff and 4 wheel drums. They did put me sideways halfway through intersections a few times, just terrible.

In high school I used to drive with the parking brake on all the time and would notice the burnt shoe aroma when exiting the highway or after getting where I was going. I never have the problem anymore since I hardly ever use the parking brake since it doesn't even work. Maybe you need this add on warning light to save your new stuff from having damage inflicted on it. I'm sure it could be wired up to some sort of switch on your center lever. You could even mount it in your console.

Maybe after I get some money together for EFI and do a few suspension things, a rear brake swap will be next.

759417
 

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Spiffy-to-the-tenth-power writeup, Kelly. Thanks so much for taking the time to document and share this mod. I'm so glad to hear it's working for you.

And, you know, I was thinking I have absolutely no need for rear discs. Just last week I had to slam the brakes on my Mach 1. You guessed it. The rear drums locked up before the front discs and I started to go sideways. Hmmmm...
 

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I'm waiting for someone to come in here and defend rear drums. The argument that drums are "cheaper" is moot, especially when factoring in horrible QC that equates to wasted time and money.

I've been preaching this for a while and I always get pushback- drum brakes are horrible. I don't care how fancy of a shoe compound you use- drums are inherently crap by design when compared to discs. I also don't care that "they were good enough for Shelby blah blah".

That was 50 years go and we were't sharing the roads with boneheads in ABS equipped cars.

No one "plans" for evasive maneuvering and braking when driving, I'd rather be prepared and not worry about my rear brakes inevitably locking up or fading.

Okay, rant over- great write up Kelly :p.
 

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I must admit I never considered going to rear disc on my car, mainly because of the parking brake question. As others have said, your write up certainly makes one want to take another look at rear disc brakes. I wonder if the kit you used could be made to work with stock parking brake setup.

Great write up and thanks for taking the time to share.

PS... I think it’s really cool that you have such appreciation for a good bench vise as a birthday gift..
 

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1965 2+2 Vintage Burgundy A-code C4
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Ok, let me ask this of the collective brain trust. If I have a peg leg, 2:79 geared, drum braked 8” and needed to upgrade gears and brakes, would I be ahead just getting an Explorer 8.8 with the brakes and gears already there and going that route? I realize I have to shorten one side and get a matching axle along with welding leaf perches. Just weighing my options here.
 

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1966 Mustang Hardtop 289 4 Speed
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Ok, let me ask this of the collective brain trust. If I have a peg leg, 2:79 geared, drum braked 8” and needed to upgrade gears and brakes, would I be ahead just getting an Explorer 8.8 with the brakes and gears already there and going that route? I realize I have to shorten one side and get a matching axle along with welding leaf perches. Just weighing my options here.
I'd gladly do that if the parts were available and cheap :p
 
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