Installing a disc brake setup from a pre-80 truck on your '65-66 Twin I Beam F100.
Everything you need, and some stuff you don't. My donor was a '78 F100. Everything you see here cost me $100 removed from the truck, but the salvage yard likes me. Depending on how you want to do the swap, you don't need the radius arms or the I-beams, you can use just the spindle from the kingpin outward. Note the proportioning valve and U shaped bracket behind it. You can toss the springs, brake hoses, shocks and radius arm rear brackets. The calipers you will need for cores (unless they are really fresh), the rotors may possibly be usable (have them measured and turned if within spec) and obviously new brake pads of your choice. You'll also need several miles of metal brake line tubing!
My conversion was to manual disc brakes, which is a little unusual but that's what I prefer. The only difference with a power brake upgrade to my knowledge is allowing for booster location and vacuum line plumbing. Everything else should be the same.
F250 owners: to my knowledge, the procedures and parts needed are the same, just from the 3/4 ton vs. the half ton illustrated here. You will need components to work with your 8 lug wheels. Of course, now is the time to 'downgrade' to five lug, half ton parts if you want a larger variety of wheel and rear axle ratio choices.
Getting Started
First, go here and print out the step-by-step instructions kindly provided by the Ford Truck Enthusiasts web site. It is well written and easy to follow, but glosses over several things that apply to our trucks that I will try to address here.
Parts: aside from the donor parts listed above from any pre-1980 pickup (NOT van), you will also need a new master cylinder (I used one from a 1974), brake line tubing (same pipe size as the existing ones), a number of fittings from the junkyard (master cylinder and prop valve fittings...large fittings but for the small size tubing...these can be taken from any Ford product), brake light switch (from early 70s Ford pickup, GM truck or similiar...don't forget the wire pigtail). You can choose to use an aftermarket proportioning valve such as a Wilwood that is much smaller and manually adjustable if you prefer. You may also want the steering linkage from the donor truck (tie rods and center link). If you are switching to power steering at the same time you'll of course need these items. To move the brake hose attachments I also bought a length of 1" square tubing.
Tools: In addition to the usual hand tools you will also need a tubing bender, 1 1/8" socket (if doing the complete suspension), grinder (if retaining stock tie rods), suitable drift for removing king pins, double flaring tool.
Depending on how you go about it, this swap can be accomplished with NO holes drilled and NO welding required!
Decision Time
At this point you need to decide which way you want to proceed. Do the entire front suspension, or just the spindles as outlined in the instructions you printed? It's been argued that doing the entire suspension can be easier. Originally, I agreed, as I had a phobia about king pin removal from reading John Jerome's excellent book "Truck" (a must read). Whacking on stubborn king pins for days didn't sound like fun to me, so I first replaced the entire suspension. This turned out to be a mistake, as my donor I-beams were bent, either damaged or simply made differently. I'm not sure which. If you decide to go the suspension route, do this first: with a straight edge, measure from the pivot point out towards the wheel at least 3/4 of the length of the beam. There will be a gap between your tool and the beam that widens as you get closer to the wheel. Measure this gap, and take the same measurement on your donor beam. It should be identical within 1/16" I'd say. Mine was 1", and it made the front wheels very bow-legged. I had to do the entire replacement over again thanks to this assumption that everything was the same. Never assume! These parts were supposed to be the same, but in my case were not. In addition:
Nothing like cutting up perfectly good, brand new parts. I purchased a threaded adjuster at the hardware store to use as a sleeve, then welded each end to it. If you're really ambitious you can thread the pushrod and make this adjustable. I chose to just measure about 20 times to make sure it was right, and welded it together. Then, when it still wasn't right, I did it over again.
Dont forget to re-use this bushing in the end of the pushrod from your old m/c. Also be sure to remove it before welding or it will turn to a blob.
The spring height is different between 'our' trucks and the donors. The donor springs are taller, so you won't want to use them.
And no, the extra height did not solve my I-beam problem. I tried that too.
The donor trucks use a nut and retainer to keep the spring in place. Here is the arrangement I came up with to remove the nut using the 1 1/8" socket. My ratchet head would not fit between the coils. This is a long, tedious process.
Now is the time to replace the pivot and radius arm bushings as well. The pivot bushings need to be pressed in.
Hopefully I've talked you out of doing it that way. It turns out the king pins weren't any big deal, though I did have one that was stuck enough that it needed numerous applications of heat and some real hefty whacks with the hammer and drift. Be careful, however, when beating on the king pins to stay centered on the pin. If your drift bounces off to the side you can damage the threads for the grease caps or the bronze bushings the king pin pivots in, making it hard to reinstall the king pin later. My truck was well maintained, so it's king pins came out easily, were nice and snug and I simply re-used them, avoiding the whole bushing/reaming nonsense. You may not be so lucky. However, I found even my neglected donor truck had nice, solid king pins without slop. These are pretty sturdy components, so I don't feel bad about just re-using them.
King Pin Tips
1) If removing on the truck, support the I beam under the radius arm point, giving a firm platform to whack away at the king pin.
2) I found it easiest to install them from the top down. If you have buggered the bushings and have to install it from the bottom, you can use a floor jack to lightly apply pressure to the pin and hammer the suspension downward. Worked very well for me. If it doesn't want to go, it's not straight. Don't force it.
3) Using a thin lube like WD-40 or PB Blaster makes installing the pins easier than using grease.
4) If the slot for the retaining bolt doesn't wind up perfectly straight, simply turning the wheel will usually line it up.
Steering Linkage
While we're out at the wheel, let's talk about the steering linkage. As illustrated below, the original tie rod threaded portion is too short for the new spindle. You can't drive the cotter pin into the hole as the castle nut won't go on far enough.
On the right is the original and donor truck steering linkages. The dimensions (length) appear the same but the angles are different. According to the FTE instructions, you should be able to simply swap linkages, and if you are changing to power steering it may require you replace them anyway. In my case, the original components were good and the donor parts were not. I also didn't want to have to remember what year parts were what for future replacement, so simply ground off about 1/8" from the nut side of the spindle to make my existing parts work. If you compare thickness of the old and new spindle in this area you won't have any fear of removing a mere 1/8"! This is not a fast process even with my air grinder; I think it took me about 45 minutes to do both sides (allowing for frequent measurement checks and for things to cool down). Also, please heed my advice and wear a mask or respirator when doing this as the iron fragments gave me severe sinus problems for several days afterward. As noted in the FTE instructions, your alignment will be totally out of whack afterwards. Do not attempt to drive the truck before performing the basic field alignment as it will be completely uncontrollable.
Brake Hoses and Lines
Oh yeah, the fun part. You'll need to make all new lines forward of the splitter block mounted on the left frame rail (remove the block). If your lines are nasty, may as well do them all now. Note how the existing lines run, clamp locations, etc as you'll want to duplicate as much of this as possible. The donor hoses will, unfortunately, be too short. You will need to move the junction point of the hose to metal line outward toward the wheel. I cut square tubing to use as a spacer between the frame rail and the hose bracket, I think they were about 1.5". If you attach the hose to the caliper and swing the spindle through it's arc you will be able to find a point where there is no excessive tension on the hose...that's how far outward it needs to be moved. Do this first, not last like I did, as those metal lines you just made will then be too short! I just got longer bolts to run through the hose bracket and spacer to the frame. You could weld them in place if it makes you feel better or you just can't leave the welder in the corner any longer. Update: see note at bottom of page.
Oh, a word about the calipers. If you've never worked on Ford truck calipers before they can be puzzling to remove with the pads in place. Remove the bolt, tap out the shim, then push the caliper upward and pull the lower portion out first. Only way it works. Pay attention how the shim pieces go together or they'll stump you later!
Bending the metal lines is a talent, and it gets better the more of them you do. I actually enjoy making them. You can use the tubing bender for most bends, but some tighter curvatures may require a piece of pipe or similiar to bend the tube around. The hardest part is the in/out from under the truck a hundred times while you test fit every change. I did run all my lines behind the steering box (because I'm anal that way). If you remove the lower bolt, and loosen the upper two the box can be pried away from the frame rail enough to easily sneak them up behind it. There will be a ton of crap there that will fall into your face, so be prepared.
My last tip here is the coiled portion of tubing for the master cylinder. I just wrapped the tubing around a propane torch bottle to get the coil size I wanted. You can also use a can of carb cleaner or a fire extinguisher (I found the can too flexible).
Proportioning Valve
Thanks to my friend Tim for this great illustration of how to plumb the lines to it. It should be noted that the front caliper line locations can be switched as needed (they will function the same). I duplicated the mounting point of my unknown year donor truck (it was just a frame) on the back side of the engine crossmember. It's a much easier place to run all the lines to than inside the frame rail as on most trucks, and it can be mounted using it's bracket and the existing hole for one of the line clamps.
This and the master cylinder will require special sized line fittings that you can pull from your donor or any other Ford truck in the junkyard. I used the end fitting from the valve donor as well as several cut off an Econoline that was just easy to access. There are a couple different fitting sizes, so get yourself an assortment instead of running to the junkyard four times like I did. Which brings us to the...
Master Cylinder
As I mentioned earlier, I used a manual disc brake setup. The power system would still have the issues described below. This is the only critical area where a precise measurement is really important. Too long a pushrod and the brakes will stick on. Too short and the pedal will be too low. Update: See end of article.
As you can see, while the cylinder bolts on perfectly, there is a problem at the pedal end. The pushrod on the new cylinder is held in by a clip and is removable. The pushrod on the original is part of the piston itself, so cannot be swapped around.
Brake Light Switch
Here's an important little component the FTE instructions completely ignore. The original brake light switch is located on the master cylinder, and is operated by hydraulic pressure. The easy solution would be to simply mount this switch in a 'T' junction and extend the wires as necessary. That would work, except that the thread type on the switch is completely different than the threads on the brake lines, and I was unable to find a fitting that would allow me to do this. I'm sure they exist, but the average parts store (and I was in 3 of 'em) couldn't come up with one. Strike One. Update: see end of article.
The early 70's Ford trucks used a GM style switch as show below, mounted to an ugly bracket that went between the pedal and lower dash. Unfortunately, besides being unattractive, the bracket on the pedal is welded on, and not easily removed to adapt to our trucks. Strike Two.
The later trucks (80's and newer) use a clever switch that mounts on the pedal/pushrod assembly, also show below. It requires no brackets or extra parts and is the easiest to install. I fell in love with this idea and it would have been perfect...except it interferes with the clutch pedal componentry on our trucks and can jam with the clutch or brake pedal, keeping it from returning fully. While it may work on automatic trucks of our vintage, it won't work with my 3 speed. Strike Three.
GM style switch
Original pressure switch
Late model Ford truck switch
I pondered this question for days. I really didn't want to weld brackets or remove the pedal assembly. Finally, with the help of some Slick 60's member ideas, I came up with the solution below. Just remove the rubber bump stop and use as a bolt hole for a simple metal bracket for the switch. The switch itself now acts as the stop.
The other solution if you have your truck really apart is to drill a hole for the switch in the pedal bracket assembly, with the switch pointing down and contacting the pedal from above. In my mind that is the best design, but the hardest to do as you can't really drill the hole with the bracket, pedals and steering column in the truck.
Update:Here is a link that shows an alternate (and probably better) way of attaching the above type switch.
The switch is adjustable and will take some finesse to find the 'sweet spot' where it holds the pedal in the proper resting place and causes the lights to go on and off correctly. Trimming some plastic off the plunger to get the correct height may be necessary. My donor switch came from a 80's Blazer.
Changing to disc brakes and a dual circuit master cylinder is an important safety upgrade that I encourage everyone to undertake. It is completely reversible should you ever want to return your truck to stock configuration, and as noted, I didn't drill a single hole in the truck for the entire job. Please feel free to email me with questions or comments, and I'll add to this page as new information is brought to light.
Addendum: I was given a tip from another owner about the brake hoses. He stated front hoses for a 1983-1987 Dodge Charger (small, fwd car) are the correct length and have the proper ends. The do have an unnecessary bracket you may need to cut off. I have not personally confirmed this application, but a trip to your local parts store should put them in your hands for consideration.
Additional Updates:
Master Cylinder: I have been told, but have not personally confirmed, that a disc brake master cylinder for a 1968 Mustang is a bolt-on and does not require the pushrod modification I lay out above. The only problem is that disc brakes were pretty rare back then, so the cylinder may not be easy to find at your local parts store. If anyone goes this route and can take photos to show it works, I'll post them here.
Hydraulic Brake Light Switch Fitting: paging through my Pegasus Racing catalog one day, I was pretty certain I found the T fitting that would adapt the brake switch into the lines. It is p/n 3209-02-03S.
Brake Pedals & Switch: I have been told, but have not confirmed, that you can swap the entire pedal assembly from some (possibly all) of the donor trucks into the 65-66 cab with no modifications. This solves both the pushrod length problem and the brake light switch in one fell swoop. Another solution added -- see below
Questions? Feel free to email me anytime.
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(A little bit more... The following was a post on the FTE forum that I thought may be helpful in giving you an idea of costs involved. The person does not follow the above instructions exactly, but then nobody says you have to!)
I finally did the disc brake conversion this week and wanted to let people know what I found. First of all the article here was very helpful. I have a 1966 F100 and used the following parts from a 1977 F100 with manual brakes. I was lucky to be the first person on this truck at the local Pick-N-Pull, on 1/2 day no less.
Both I-Beams with spindles, rotors, calipers, no brake hoses.
I took the passenger side frame bracket that holds the brake line to brake hose from this truck and another F150 I found. The drivers side has a rivit holding it in but the passenger has two bolts.
I also got the proportioning valve and bracket.
Cost $112.00 (I thought this was a steal)
From Kragen I purchased the following parts, one note on Kragen is if you go online and print out the part and then go to the store, they will match their online price which is quite significant. For example the store price for one wheel seal is 5.99 and the online price is .89 cents.
1977 F100 Master cylinder with manual brakes, includes push rod
1977 F100 right and left brake boses and the wheel seals and one rotor to replace one that had a groove and a stoplight switch
Master cylinder Part #101667 14.99 plus 5.00 core
Right brake hose Part #4536748 14.99
Left brake hose Part #4536749 14.99
Quart brake fluid 4.99
Stoplight switch Part #SL31181 3.89
Disc Rotor Part #6032RGS 32.99
2 wheel seals Part #C19743 1.78
Cost $95.93 with taxes
Second trip to Pick-N-Pull when I decided to not grind down the spindles,
I got the centerlink, tie rod ends and pitman arm off a 1976 F100. The 1977 was gone.
Cost $51.00
I had to go to Napa and get hardlines and various adapters to take the connectors on the proportioning valve down to the 3/16 lines. I also used 1/4 for the master cylinder to the proportioning valve for the front. I don't know why they have big nuts for the small lines, but Napa had all the lines and adapters.
Cost $67.00
I had the machine shop turn one rotor, the other had a serious groove.
Cost $20.00
The actual installation was very smooth and well worth the effort. The alignment was pretty dead on. The alignment cost was $60.00
So all said and done my total cost was $405.93
I had a piece of 1 inch flat steel that I bent into a 90 degree and drilled two holes, one for the bolt that previously held the brake pedal stop and one hole for the new stoplight switch. Very easy conversion.
I cut exactly 3/4 of an inch out of the brake pedal push rod that came with the master cylinder. Then I welded it back up. The pedal is right on, same height as clutch pedal.
I removed the original brake hose brackets and used the two passenger side brackets from the 1977 donors. I bolted the proportioning valve to the cross member below the master cylinder where it was on the 1977.
So thanks to all the previous owners who have done this as it made my job alot easier.
Jim
Yet another brake pedal switch solution
Click here to see a solution by one of the members of Slick 60s.org complete with photos and diagrams.
Note: many updates have been provided by those who have used these instructions. Be sure to read the entire page for the most recent tips!
