Rear Disk Brake Conversion Questions

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I actually went with Willwood disk brakes on the rear of my '68. I had an issue with the Bear E-brake binding in a previous car. I love my 4-wheel disks. And on a heavier car such as my '73. I wouldn't not have 4-wheel brakes. But I guess it's all personal preference.

 
Q has a good post and (I think) a video about the rear disk conversion using factory late model cobra parts he sourced from Rock Auto.

Also, in general six cylinder and 302 2V equipped cars got 8" rears. All others got 9" but we are talking Ford here so it wouldn't surprise me if someone posted an exception to this statement.

 
Really? I've been upgrading my suspension over the years and I find that the brakes, with sintered metal pads, stock size front rotors, and rear drums does a passable job of handling braking duties while driving, but it doesn't feel confident. I figured that a rear disc brake conversion might help with improving the repeatability of heavy braking. Sort of on the wall about it at the moment... I do lot of driving through the twisties (canyons mostly).
I believe that well set up rear drums with premium front brakes will do an admirable job for even somewhat aggressive driving. Lots of twisties may tip the scales in the direction of disc brakes in back, but if it also requires new MC, lines valves ebrake cables , larger wheels and tires it is a couple grand commitment. I like mine, but if I had to do it again, I don't think I'd spend all the money it takes to do it right.

Just my opinion

 
Q has a good post and (I think) a video about the rear disk conversion using factory late model cobra parts he sourced from Rock Auto.

Also, in general six cylinder and 302 2V equipped cars got 8" rears. All others got 9" but we are talking Ford here so it wouldn't surprise me if someone posted an exception to this statement.
Yeah, I did the late model Cobra upgrade to the front and rear of my '89 5.0 and was thinking of doing something similar to the '71, but just for the rear. The front brakes on the '71 (at least mine) perform great. I used Rock Auto calipers, some brackets from North Racecars, and had stainless lines made up by a local shop to finish the 5.0, it turned it out really nice. Not a fan of the Wilwood and Baer parts, would rather stick with factory Ford components for the upgrade.

I want to stick with the 15" wheel setup I have at the moment on the '71, although I did upgrade to 17" wheels on the 5.0.

 
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Really? I've been upgrading my suspension over the years and I find that the brakes, with sintered metal pads, stock size front rotors, and rear drums does a passable job of handling braking duties while driving, but it doesn't feel confident. I figured that a rear disc brake conversion might help with improving the repeatability of heavy braking. Sort of on the wall about it at the moment... I do lot of driving through the twisties (canyons mostly).
I believe that well set up rear drums with premium front brakes will do an admirable job for even somewhat aggressive driving. Lots of twisties may tip the scales in the direction of disc brakes in back, but if it also requires new MC, lines valves ebrake cables , larger wheels and tires it is a couple grand commitment. I like mine, but if I had to do it again, I don't think I'd spend all the money it takes to do it right.

Just my opinion
I don't disagree on the capability of the OE brake hardware under "normal" conditions. I did have the rears "self energize" and lock up in a panic situation a couple of summers ago. Ending up sideways on a major local highway made me re-evaluate the drums. It moved the brakes up on the to do list.

 
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That makes me feel better about my decision, and my brakes do work well considering I max out at 15" of vacuum for the power assist. I still may go to full manual before I am satisfied though. See what I mean? Always a tweak or improvement left to be made

 
That makes me feel better about my decision, and my brakes do work well considering I max out at 15" of vacuum for the power assist. I still may go to full manual before I am satisfied though. See what I mean? Always a tweak or improvement left to be made
Nothing wrong with 4 wheel disc manual in my book

 
Or.. If vaccum is the issue, can't you run a vaccum canister?

 
Really? I've been upgrading my suspension over the years and I find that the brakes, with sintered metal pads, stock size front rotors, and rear drums does a passable job of handling braking duties while driving, but it doesn't feel confident. I figured that a rear disc brake conversion might help with improving the repeatability of heavy braking. Sort of on the wall about it at the moment... I do lot of driving through the twisties (canyons mostly).
I believe that well set up rear drums with premium front brakes will do an admirable job for even somewhat aggressive driving. Lots of twisties may tip the scales in the direction of disc brakes in back, but if it also requires new MC, lines valves ebrake cables , larger wheels and tires it is a couple grand commitment. I like mine, but if I had to do it again, I don't think I'd spend all the money it takes to do it right.

Just my opinion
I don't disagree on the capability of the OE brake hardware under "normal" conditions. I did have the rears "self energize" and lock up in a panic situation a couple of summers ago. Ending up sideways on a major local highway made me re-evaluate the drums. It moved the brakes up on the to do list.
i too ended up side ways a few times with the drums.

now with the rear cobra disc, it says you should use a 16 wheel but i am using a 15 on them no problem. if you keep your BS to a 5.5 then you won't have any problems. if you want more backspacing then you will need to play with low profile banjo bolts and machining of the brake line fitting like i am right now. with a 15, you could get a 10 wide rim with 5.5 that will work great.

get the cobra rear bakes homie, you'll thank urself later.



Or.. If vaccum is the issue, can't you run a vaccum canister?
on my 521 stroker i had 7 inches of vacuum and the only time it was iffy was at idle. i had no canister, however i have a new one sitting in the garage waiting for the install of the new motor.

 
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I believe that well set up rear drums with premium front brakes will do an admirable job for even somewhat aggressive driving. Lots of twisties may tip the scales in the direction of disc brakes in back, but if it also requires new MC, lines valves ebrake cables , larger wheels and tires it is a couple grand commitment. I like mine, but if I had to do it again, I don't think I'd spend all the money it takes to do it right.

Just my opinion
I don't disagree on the capability of the OE brake hardware under "normal" conditions. I did have the rears "self energize" and lock up in a panic situation a couple of summers ago. Ending up sideways on a major local highway made me re-evaluate the drums. It moved the brakes up on the to do list.
i too ended up side ways a few times with the drums.

now with the rear cobra disc, it says you should use a 16 wheel but i am using a 15 on them no problem. if you keep your BS to a 5.5 then you won't have any problems. if you want more backspacing then you will need to play with low profile banjo bolts and machining of the brake line fitting like i am right now. with a 15, you could get a 10 wide rim with 5.5 that will work great.

get the cobra rear bakes homie, you'll thank urself later.



Or.. If vaccum is the issue, can't you run a vaccum canister?
on my 521 stroker i had 7 inches of vacuum and the only time it was iffy was at idle. i had no canister, however i have a new one sitting in the garage waiting for the install of the new motor.
So '94-04 Cobra rear calipers and rotors with 15" wheels? I've got 15x10 Weld Draglites on the rear, was thinking maybe the GT setup with smaller 10.6" rotors would fit nicer.

Did everyone use Mustang Steve caliper brackets? Anyone use the North Racecars pieces? Can anyone shed some light on whether we've got the big or small bearing 9"?

Cheers!

 
i got a 35 spline with small bearing. now, a 15 will fit over a cobra 10.65 rotor but don't go more than 5.5BS, better yet, go with a 4.5-5.5bs.

for me to fit a 5.5BS i had to touch the banjo bolt with a grinder a bit and the emergency brake end. very easy.

i'm going to go with a low profile banjo bolt and machined down brake line to fit in there deeper.

trust me, i've done alot of test fitting with these brakes and what fits these cars.

 
You know now that think about it, my drum breaks "energized" one time during a panic stop too. The car jacked sideways until I got off them and recovered. I think I'm going to go after a 95 + Crown Vic diff and Disk set up and maybe change the gears if Im not happy with the ratio.

Thanks for all the input

 
An easy fix for low or no vacuum is to run a small electric vacuum pump off of a ....... wait for it..........wait for it..............Ford Escort. (Insert eeeew yuk here).

I have installed several on my stupidly over cammed engines in the past and they work great. Just T them into the stock set up and wire them to work with the key in the run position. They are not noisy and you will have all the vacuum assist you will ever need.

The Crown Vic rear end swap is also very easy and cheap. I agree that disk / drums work fine for a daily driver and I have only swapped to rear disk when I had to repair or replace what I had anyway. It was always cheaper and looked cool when we were done.

- Paul

 
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