Mad Scientist
07-08-2009, 10:21 PM
OK let me start off the technical section with my disc brake conversion. This is just a cut and paste from the Lincoln forum but I believe that it belongs here.
How to add DISC BRAKES to a MKII.
First off the original drum brakes on the MKII were not all that bad for a car of its vintage. They are actually able to rather quickly stop the car from 80 MPH which is something not all cars of that era could do. Still compared to modern discs they leave much to be desired. Thus I decided to upgrade my MKII. After not having any luck in trying to purchase a ready make kit naturally the only option was to do-it-myself.
After talking to a couple vendors I had a pretty good idea of what they would do if they were willing to do it.
The problem with the MKII and Lincolns of its era is that their axles were slightly larger in diameter thus no modern rotor will fit them. It would seem that the only cars that use this size of wheel bearings are some old Packard’s, Nash’s and a Ferrari. Thus trying to find a ready made rotor was out of the question.
The solution for this is to use the hub from the original brake drum. By removing the wheel studs the hub falls out of the drum. Then with a slight amount of “precision” machining a Ford 4WD truck rotor can be attached using longer wheel studs.
I started out by spending a lot of time carefully measuring the old drum, its hub, the axle and the inside of the wheel rim, etc. Using a CAD program I drew a composite of the wheel assembly. To this I then added the calipers and positioned them to fit. Next I designed the mounting brackets for them. The calipers are a GM unit for a 78 Suburban. Yes Yes I know there are some that would consider this as sacrilegious using GM parts on a Ford. But these are decent calipers with a very large diameter piston, plus their use of two round pins for mounting makes it easy to design a mounting bracket. Conversely trying to design a simple mounting bracket for Ford’s calipers with their square pins is like well forget it. At the end of this I have included all my dimensioned drawings and a parts list.
To test of my dimensions I made the first mounting brackets out plastic. Tweaked a few dimensions and then made the real ones out 3/8” thick steel plate. From what I’ve read I probably could have used thinner material as this is undoubtedly overkill, but it is strong and I certainly don’t want my brakes to break.
First removed the old drum and backing plate, but save the grease catcher ring.
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B1.jpg
Remove hub from drum by simply pressing out the wheel studs.
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B2.jpg
To be able machine the hub to fit the rotor first make a precision mandrel to mount it on, or barrow one from someone that has one. This is the only way to insured that it can be turned absolutely concentric with its original axis. You don’t what a wobbly rotor.
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B3.jpg
Hub mounted on mandrel. Diameter of the inner ridge will need to be cut down about a ¼”.
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B4.jpg
Turn ridge down to fit center hole in the 4WD rotor and a very light face cut to insure a flat mounting surface. Note: This ridge needs to cut a 45 degree angle to match the bevel that Ford in it infinite wisdom decided to add to this rotor. :(
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B5.jpg
The rotor is mounted to the back of the hub with new slightly longer studs. (This provides the need clearance for the calipers.)
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B6.jpg
Make new backing plates per drawings.
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B7.jpg
Then make the caliper mount brackets. These may take awhile to do..
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B8.jpg
Finally make a bunch of spacers a couple torque arms and then paint or powder coated all the parts.
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B9.jpg
When assembled it should look something like this.
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B10A.jpg
The nuts and bolts are all grade 8 hardware.
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B11.jpg
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B12A.jpg
Rotor and caliper mounted! And yes the stock wheels should fit and can be used with no changes required.
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B13.jpg
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B14.jpg
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B15.jpg
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B16.jpg
Next I wanted to go with a dual master cylinder however the original master cylinder is part of the power assist. So I wound up getting a new master cylinder and power assist (with dual diaphragm) that would have normally been used in a pickup. Naturally a few modifications were required.
First I could not mount it flush on the firewall. Seems that its “nose” stuck out further the original and it hit the arm of the brake peddle. So I had to make a mounting plate and some spacers to provide the necessary clearance.
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B17.jpg
Of course the actuating rod is way too short so that calls for making an extension. Tape up the end of power booster to keep from getting chips into the housing. Then cut off the original mounting eye leaving as much of the rod as possible and then cut a thread (3/8-24) for about ½” on the end of the actuating rod. Note: As the instructions that come with the booster state the plastic tube that surrounds the actuating rod is fragile if you break it, its back to the parts store to buy a new unit. Be very careful here. (This piece slides in and out of the housing when the brakes are applied.)
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B18.jpg
The actuator rods extender is a 3/4” diameter steel bar with each end drilled and tapped for a 3/8-24 thread. On the end that screws onto the booster it is cross drilled and taped with an 8-32 thread to provide a lock to prevent it from unscrewing.
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B19.jpg
With everything mounted and the hood should close with about ¾” to spare.
With a disc/drum brake set up a hold off valve for the front brakes is needed. This gives the rear brake time to engage before the front one start to work. I found a reasonably priced one at a “speedshop” then mounted to the frame under the steering gear box, an adjustable pressure valve for the rear brakes may also be needed to prevent rear wheel lock up under hard braking. This is yet to be determined.
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B20.jpg
At this point I have a car that should be able to stop; next I need put the engine in so I can make it go.
The following are my dimensioned drawings for making the parts.
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B21.jpg
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B22.jpg
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B23.jpg
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B24.jpg
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/dwg6-1.jpg
Correction that should be two rotors.:o
How to add DISC BRAKES to a MKII.
First off the original drum brakes on the MKII were not all that bad for a car of its vintage. They are actually able to rather quickly stop the car from 80 MPH which is something not all cars of that era could do. Still compared to modern discs they leave much to be desired. Thus I decided to upgrade my MKII. After not having any luck in trying to purchase a ready make kit naturally the only option was to do-it-myself.
After talking to a couple vendors I had a pretty good idea of what they would do if they were willing to do it.
The problem with the MKII and Lincolns of its era is that their axles were slightly larger in diameter thus no modern rotor will fit them. It would seem that the only cars that use this size of wheel bearings are some old Packard’s, Nash’s and a Ferrari. Thus trying to find a ready made rotor was out of the question.
The solution for this is to use the hub from the original brake drum. By removing the wheel studs the hub falls out of the drum. Then with a slight amount of “precision” machining a Ford 4WD truck rotor can be attached using longer wheel studs.
I started out by spending a lot of time carefully measuring the old drum, its hub, the axle and the inside of the wheel rim, etc. Using a CAD program I drew a composite of the wheel assembly. To this I then added the calipers and positioned them to fit. Next I designed the mounting brackets for them. The calipers are a GM unit for a 78 Suburban. Yes Yes I know there are some that would consider this as sacrilegious using GM parts on a Ford. But these are decent calipers with a very large diameter piston, plus their use of two round pins for mounting makes it easy to design a mounting bracket. Conversely trying to design a simple mounting bracket for Ford’s calipers with their square pins is like well forget it. At the end of this I have included all my dimensioned drawings and a parts list.
To test of my dimensions I made the first mounting brackets out plastic. Tweaked a few dimensions and then made the real ones out 3/8” thick steel plate. From what I’ve read I probably could have used thinner material as this is undoubtedly overkill, but it is strong and I certainly don’t want my brakes to break.
First removed the old drum and backing plate, but save the grease catcher ring.
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B1.jpg
Remove hub from drum by simply pressing out the wheel studs.
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B2.jpg
To be able machine the hub to fit the rotor first make a precision mandrel to mount it on, or barrow one from someone that has one. This is the only way to insured that it can be turned absolutely concentric with its original axis. You don’t what a wobbly rotor.
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B3.jpg
Hub mounted on mandrel. Diameter of the inner ridge will need to be cut down about a ¼”.
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B4.jpg
Turn ridge down to fit center hole in the 4WD rotor and a very light face cut to insure a flat mounting surface. Note: This ridge needs to cut a 45 degree angle to match the bevel that Ford in it infinite wisdom decided to add to this rotor. :(
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B5.jpg
The rotor is mounted to the back of the hub with new slightly longer studs. (This provides the need clearance for the calipers.)
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B6.jpg
Make new backing plates per drawings.
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B7.jpg
Then make the caliper mount brackets. These may take awhile to do..
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B8.jpg
Finally make a bunch of spacers a couple torque arms and then paint or powder coated all the parts.
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B9.jpg
When assembled it should look something like this.
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B10A.jpg
The nuts and bolts are all grade 8 hardware.
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B11.jpg
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B12A.jpg
Rotor and caliper mounted! And yes the stock wheels should fit and can be used with no changes required.
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B13.jpg
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B14.jpg
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B15.jpg
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B16.jpg
Next I wanted to go with a dual master cylinder however the original master cylinder is part of the power assist. So I wound up getting a new master cylinder and power assist (with dual diaphragm) that would have normally been used in a pickup. Naturally a few modifications were required.
First I could not mount it flush on the firewall. Seems that its “nose” stuck out further the original and it hit the arm of the brake peddle. So I had to make a mounting plate and some spacers to provide the necessary clearance.
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B17.jpg
Of course the actuating rod is way too short so that calls for making an extension. Tape up the end of power booster to keep from getting chips into the housing. Then cut off the original mounting eye leaving as much of the rod as possible and then cut a thread (3/8-24) for about ½” on the end of the actuating rod. Note: As the instructions that come with the booster state the plastic tube that surrounds the actuating rod is fragile if you break it, its back to the parts store to buy a new unit. Be very careful here. (This piece slides in and out of the housing when the brakes are applied.)
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B18.jpg
The actuator rods extender is a 3/4” diameter steel bar with each end drilled and tapped for a 3/8-24 thread. On the end that screws onto the booster it is cross drilled and taped with an 8-32 thread to provide a lock to prevent it from unscrewing.
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B19.jpg
With everything mounted and the hood should close with about ¾” to spare.
With a disc/drum brake set up a hold off valve for the front brakes is needed. This gives the rear brake time to engage before the front one start to work. I found a reasonably priced one at a “speedshop” then mounted to the frame under the steering gear box, an adjustable pressure valve for the rear brakes may also be needed to prevent rear wheel lock up under hard braking. This is yet to be determined.
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B20.jpg
At this point I have a car that should be able to stop; next I need put the engine in so I can make it go.
The following are my dimensioned drawings for making the parts.
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B21.jpg
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B22.jpg
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B23.jpg
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/B24.jpg
http://i68.photobucket.com/albums/i17/mscientist/MKII%20brakes/dwg6-1.jpg
Correction that should be two rotors.:o