Advice on brake conversion kits

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slowpoke17

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My Car
1973 coupe
I'm going to replace the manual drum brakes and go with the power discs up front and keep the drums in the rear. I see a lot of conversion kits out there, some seem more complete than others. What I'm looking for is a complete kit that will include everything for the swap. Based on everyone experience that did this, can anyone offer any tips on what  to look for, best company for completeness, ease of installation and quality. Thanks

 
I'm going to replace the manual drum brakes and go with the power discs up front and keep the drums in the rear. I see a lot of conversion kits out there, some seem more complete than others. What I'm looking for is a complete kit that will include everything for the swap. Based on everyone experience that did this, can anyone offer any tips on what  to look for, best company for completeness, ease of installation and quality. Thanks
 For a low buck and great quality, my choice was SSBC 4 piston Kelsey-Hayes style. They fit right onto your drum spindles and very easy to do. When I did mine, I also changed all the brake lines. I chose SS, but good quality steel lines will last longer than the rest of the car, easier to work with as well. You will need new flex lines for sure. You can get these brakes from National Parts Depot amongst others. Oh, these will work with 14" wheels. I run aftermarket Magnum 500's. Also, forgot to mention, I did not have a power booster for the first 3 years, only adding that 2 years ago. On the back circuit, I used a separate adjustable control valve that came with the kit. The original prop valve is now just a joiner for the front brakes. Downside is I lost my brake warning idiot light. Oh well too bad!!

Geoff.

 
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 For a low buck and great quality, my choice was SSBC 4 piston Kelsey-Hayes style. They fit right onto your drum spindles and very easy to do. When I did mine, I also changed all the brake lines. I chose SS, but good quality steel lines will last longer than the rest of the car, easier to work with as well. You will need new flex lines for sure. You can get these brakes from National Parts Depot amongst others. Oh, these will work with 14" wheels. I run aftermarket Magnum 500's. Also, forgot to mention, I did not have a power booster for the first 3 years, only adding that 2 years ago. On the back circuit, I used a separate adjustable control valve that came with the kit. The original prop valve is now just a joiner for the front brakes. Downside is I lost my brake warning idiot light. Oh well too bad!!

Geoff.

Thanks Geoff, I didn't even think of NPD, I checked the two big suppliers. I plan to do the booster at the same time. Someone mentioned that you also need to replace the brake pedal or redrill the pivot point with the new booster. I did see one kit that included a new pedal as well. My brake lines are shot so that is also on the ticket with a new fuel line from the tank forward. 
 
I also have a manual Drum Car and am also working on the brakes right now.

I am in the process of changing out all the lines to SS Disc lines.

Some observations.....

The Bracket that secures the front Brake Hose appears to be different on a Disc car than a drum car. When you get the Disc Lines, they will have bends in them that wont match up to your drum hose bracket, so you may have to bend them a bit. I did, and it wasnt hard.

Drum Car Bracket



Disc Car Bracket



The Ends of the Disc Brake Line Kit Will be different in some places than the Drum Line Kit.  ie, the master cylinder lines will have different fittings.   Depending on which proportional valve you use, you may need different fittings on the new lines.  If you stick with Mustang specific parts, everything should work fine.  If you go with an after market Proportional valve like I did, The ends will be different.  If you go stainless, you do not want to be changing ends.  So make sure you order the lines with the correct ends.



Conversion Kit.

I also like the SSBC Kit.  It is inexpensive and will fit.  I havnt got it yet, but its on my list.

https://www.npdlink.com/product/disc-brake-conversion-kit-street-bandit-front-drum/207115/200824



Master/Booster Upgrade.

If your kit doesnt come with the master and brake booster, you will need to get them.

I prefer the LEED Brakes 9" Booster.  If you ask nicely when you order they will also send you the new Bolt on Pivot Point for the pedal.

https://leedbrakes.com/i-21155650-9-inch-power-brake-booster-black.html



You could also go with the master/booster combo.

https://leedbrakes.com/i-21155649-hydraulic-kit-power-brake-booster-kit-71-73-ford-mustang.html



You will need to remove the Drivers side Shock Tower Brace for access.  Then Remove the Drum Master Cylinder and disconnect from pedal, and brake switch. (Giant pain in the ass, remove the seat first.)

 This will leave you with 2 Studs holding the Pedal Assembly in place.  Remove the 2 Studs by threading on a nut, then a 2nd nut and lock them into each other, then turn the inside nut to rotate the stud bolt out.

Once the pedal assembly is out You can remove the pedal from the bracket.  If you can, this would be a good time to blast and paint/powder coat all that stuff.

Then using a drill press, drill the hole for the new bolt in pivot point.  Since the rod on the booster is lower than the drum master, it must be relocated.

You can bolt it on, or bolt it and weld it in place.

While everything is out, replace all your lines.  This will be immeasurable fun!  You will need to unbolt the Emissions canister and preferably the vacuum canister to get access to the passenger side lines and union.

Use these Reference pictures as a guide.















Then Put back together and mount the booster and pedal assembly.

Mount the Master Cylinder AFTER Bench Bleeding.  Install the lines pointing up so they wont leak fluid and loose prime on the master.

Connect it all up and bleed it.  it will be lots easier to bleed the disc brakes than the drums were.

 
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Excellent help and information!!! Thank you so much, these photos will be saved and printed for sure. Your car is looking really good too, it's an inspiration on what I hope my car will look like when completed. Thank you again.

 
well that one is not mine. Thats the Motorcity Mustang Grabber Lime restoration. A very excellent car.

The really rusty looking one is mine.

 
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 For a low buck and great quality, my choice was SSBC 4 piston Kelsey-Hayes style. They fit right onto your drum spindles and very easy to do. When I did mine, I also changed all the brake lines. I chose SS, but good quality steel lines will last longer than the rest of the car, easier to work with as well. You will need new flex lines for sure. You can get these brakes from National Parts Depot amongst others. Oh, these will work with 14" wheels. I run aftermarket Magnum 500's. Also, forgot to mention, I did not have a power booster for the first 3 years, only adding that 2 years ago. On the back circuit, I used a separate adjustable control valve that came with the kit. The original prop valve is now just a joiner for the front brakes. Downside is I lost my brake warning idiot light. Oh well too bad!!

Geoff.

Thanks Geoff, I didn't even think of NPD, I checked the two big suppliers. I plan to do the booster at the same time. Someone mentioned that you also need to replace the brake pedal or redrill the pivot point with the new booster. I did see one kit that included a new pedal as well. My brake lines are shot so that is also on the ticket with a new fuel line from the tank forward. 
 When I did my upgrade to booster, yes I needed to relocate the push rod pin down 2". BUT I went the hole hog and as my car is a manual trans, and stripped out the column as well as the bracket and installed ball bearings for the clutch shaft ( Mustang Steve's conversion). If you or anyone else is working with a factory manual trans, do this mod if nothing else. Huge difference on the effort needed to disengage the clutch!!

This has been posted before, but here is a pic of my modded pedal arm. This pin was welded in. Also a couple of other pics that might be helpful. Note the mounted rear brake bias valve.

 
Excellent help and information!!! Thank you so much, these photos will be saved and printed for sure. Your car is looking really good too, it's an inspiration on what I hope my car will look like when completed. Thank you again.
Has anyone checked out the Scott Drake kit offered on CJPony?

https://www.cjponyparts.com/scott-drake-front-power-disc-brake-conversion-kit-with-drilled-slotted-rotors-automatic-transmission-v8-1971-1973/p/DBCA134ADS/

I've been researching brake options and like the option of a total kit with pretty much everything included. But on the other hand I've read lots of reviews on Drake products and it can be hit or miss when it comes to quality. Anyone have any experience with this or a similar kit?

Also, what are y'all doing for the rear? I don't see the point in upgrading to disc in the rear, anyone have a recommendation for a good drum upgrade for the best performance?

 
Excellent help and information!!! Thank you so much, these photos will be saved and printed for sure. Your car is looking really good too, it's an inspiration on what I hope my car will look like when completed. Thank you again.
Has anyone checked out the Scott Drake kit offered on CJPony?

https://www.cjponyparts.com/scott-drake-front-power-disc-brake-conversion-kit-with-drilled-slotted-rotors-automatic-transmission-v8-1971-1973/p/DBCA134ADS/

I've been researching brake options and like the option of a total kit with pretty much everything included. But on the other hand I've read lots of reviews on Drake products and it can be hit or miss when it comes to quality. Anyone have any experience with this or a similar kit?

Also, what are y'all doing for the rear? I don't see the point in upgrading to disc in the rear, anyone have a recommendation for a good drum upgrade for the best performance?
 Can't be sure, but that looks awfully like the SSBC brand being sold under SD name. If not it's a copy. I do like the drilled rotors though. On the SSBC kit I bought, I got the slotted rotors upgrade, but that was back in 2010 and things change.

Back brakes, these cars are so light on the back end, I found that drums are sufficient and in fact as you have seen, there is a bias valve to cut the braking to a minimum. A problem I do have is the car is a "one-wheeler-peeler", so very easy to lock up the rear left wheel.

Geoff.

 
I've been researching brake options and like the option of a total kit with pretty much everything included. But on the other hand I've read lots of reviews on Drake products and it can be hit or miss when it comes to quality. Anyone have any experience with this or a similar kit?

Also, what are y'all doing for the rear? I don't see the point in upgrading to disc in the rear, anyone have a recommendation for a good drum upgrade for the best performance?
I ended up purchasing the complete conversion kit from CJ Pony/Scott Drake. Set me back $900, haven't had a chance to install anything yet but out of the box everything looks like good quality and heavy duty. I don't plan on doing anything to the rear except a drum brake refresh with new drums, cylinders, shoes etc.

I'm just waiting for March to get here, I'll bring the car in the garage and get it up on the lift so I can start! I have a new gas tank, fuel and brake lines, new front brakes and some other work I need to get started on.

 
I bought the Leed Brakes front power disc kit and had it installed two weeks ago. Best thing I ever did to the car! Uses 67-68 Mustang rotors and 71-73 wheel bearings, and 65-66 Mustang calipers. With the front drums there was no intuition and no feel to the braking experience and braking towards corners was like guiding a barge. The new power brakes means you can head into corners stress free just like a normal modern car!

I did hand mine over to a brake shop to install though, could have done it myself but lacked a bit of confidence to do so.

The brake guy did remove the seat to get at the brake pedal for pedal removal and modification, but he didn't have to remove the steering column to do so. I told him to just cut an access hole in the existing firewall cover plate (it's only the thickness of a bit of tin) to create access for the power booster shaft, so there was no need for him to remove the whole pedal bracket assembly.

One note that a kind person on this forum advised me, is that the holes where the power booster attaches through the firewall need the threads drilling out so the booster studs will go through them. These holes in the firewall are 3/8" threaded, so a 3/8" drill is needed just to get rid of the thread.

Another note, the brake lights stopped working with the new brakes. Doing some research I found that there are two different brake switches used for power and drum brake cars. The switches look identical however the power brakes switch has a weaker spring in it than the drum brake switch so that it doesn't take as much force to activate it. Put the power brake light switch in and the brake lights work fine now.

 
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i have a question , if i already have front disc and just add the rear do i still need to change all the other stuff , it is a power break car ??
 
You have to change your master brake cylinder. It has to have a larger fluid capacity for the rear disc brakes and one that does not restrict the pressure to the rear. The stock proportioning valve is okay, but after 50 years of service it should be rebuilt, or you have the option of purchasing an adjustable valve.
If you have a 9” rear axle, and if I remember correctly, the mid 90’s crown Victoria has rear disc brakes that will bolt right up.
 
You have options for the master brake cylinder. Some have used corvette master cylinders, but they are physically big and I personally don’t like the looks of it. I used a Baer master cylinder, it was expensive, but it’s a really nice unit.
 
If you have front disc brakes, then there is no need for rear disc. The drum brakes are plenty adequate enough for any street driven car. Unless you are racing , the rear disc are a waste of time and money. I believe you can even get larger drums and pads that will give more breaking for the rears.
 
If you have front disc brakes, then there is no need for rear disc. The drum brakes are plenty adequate enough for any street driven car. Unless you are racing , the rear disc are a waste of time and money. I believe you can even get larger drums and pads that will give more breaking for the rears.
I would swap to rear discs for no other reason than I hate servicing drums/shoes. Its not all about stopping power.
 
I totally agree with JPAZ about keeping rear drums. Shelby even found that the most cost and time efficient way to add more stopping power to the mustang was to add larger drums in the rear. Mechanically, drums have more stopping friction area than discs, but, in heavy use, tend to get hot and suffer fade before discs will. The deal there was to use special shoe linings, and add brake cooling scoops on the cars to duct cooling air to the drums. ( See a GT-350). Disc brake race cars can suffer brake fade too! ( See Ford vs. Ferarri ). I don't race my Mach, but I do drive it everyday, and tow with it in the summer, and have found the front disc/rear drum stock braking trouble free . Add rear discs if you want, it's fun to modify, but you'll be OK with the factory set up as well.
 
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i have some thoughts to share re: replacing front drum brakes with front power disc brakes... First of all, do not go cheap. Doing this correctly is going to be fairly costly. There are three things I never compromise with quality; brakes, suspension parts, and tires. For a conversion like this I recommend getting a complete kit, with the proper master cylinder, and power booster. This is no time to play mix-n-match.

Next, if you insist on using the old master cylinder please be aware the outlet port for the front wheel cylinders (for drum barakes) and rear wheel sylinders bth use a Residual Pressure Check Valve, installed under the brass seat for both outlet ports. The outlet port used for the front disc brakes MUST hve its outlet pot Residual Pressure Check Valve removed. The master cylinder outlet fot the rear drum brakes, however, must have a Residual Pressure Check Valve installed. A document is attached going into more detial.

Finally, if you wind uo using own single piston floating caliper equipment, it is entirely possible to insrall the caliper on the wrong side of the car, If that happens you will never be able to bleeed the front calipers. Please refer to the one front disc brake caliper drawing to see why this is.
 

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