F250 Straight Axel disk brakes

[FarmMotorSports]

I'm one step closer to having the Uni at SS.


All ford parts, and they even clear the old rims.


Do the one ton trucks use the same 8 lug hubs, with 6 lug adapters?
If so this may work for tonners too..

[jamesdfo]

Nope, the One Tons are 6 bolt on 7.25" BC

James

Do the one ton trucks use the same 8 lug hubs, with 6 lug adapters?
If so this may work for tonners too..

[aj64f100390-292]

I'm one step closer to having the Uni at SS.


All ford parts, and they even clear the old rims.


Do the one ton trucks use the same 8 lug hubs, with 6 lug adapters?
If so this may work for tonners too..

See...WTH don't the f100 kits use ford calipers ...really bugs me..Ill do it eventually..and NO backing plates...not trying to hi-jack the thread though Nice job looks good

[rwhistles]

ok spill the beens. need the full details plus part numbers for everything. what kind of caliper anchor did you use?

[FarmMotorSports]

1980-1994 F250 rotors. Part # YH141237
2001-2007 F250 calipers with brackets. Part # 18B4652 & 18B4653, right & left

3/8" flat plate bracket. I have some CAD files if needed. (Cardboard Aided Design) -paper template.

Misc parts not accounted for yet. Banjo bolts, &copper gaskets
- Braided brake lines for lifted 4X4 1985ish
- Wilwood proportioning valve, drum brake residual valve.
- I'm using a hydroboost and master cylinder for a E450 powerstroke - My choice... there are other choices.
The above referenced F250's have boosters and MC's that will work nicely .


Rotors are attached to the back of the stock F250 hubs with longer studs, just like they would on a 1980-1994.
One of my hubs needed machining on the back, the other did not... 1/8" deeper cut toward the center on the back side.

[FarmMotorSports]

I used 9/16 studs... the key is knurl diameter and the knurl reaching thru the rotor to the hub. Size 1/2" or 9/16" is your choice. From there it is almost straight forward. A 3/8" plate cut to match my template. Plate bolts on after the steering arm so a 1" spacer is needed for the top fasteners. Those fasteners will need to be longer thanks to the 3/8" plate.

[FarmMotorSports]

From there, pads of choice, cheap to high $$$ ceramics. MC/ booster of your liking, a factory proportioning valve is good enough. I went wilwood because it was easier to order an adjustable one than spend a day at the junk yard..And I can adjust it if I ever need or want to. It came with a brake light switch. Two birds one stone.

Bolts I used were grade 8 with crimped steel self locking nuts. I used a second set of steering arms chopped up for spacers behind the 3/8" steel brackets, but it was defiantly over kill.



Any non Ford parts I used or will use can be replaced with the 1994 ish F250 parts... soft brake lines etc.
Disks up front require changing almost everything up front, lines, MC, booster, brake light switch, etc...

I'm can maybe do a step by step post later. I didn't figure there would be all that many 3/4 ton straight Axel guys wanting to go disk.... figured they would go CV or dakota and five lug!

[bruceandersson]

Great work and good information. Thanks for posting!

[rwhistles]

how did you realize one hub needed to be back cut and how did you figure the amount to be removed?

[orangeRcode]

Nicely done Pat. Great write-up.

[FarmMotorSports]

The hubs are only cut enough on the back side for the studs to penetrate evenly thru the surface.

For me this meant one hub did not have enough removed to slide in the rotor and lay flat.(The unfinished center hit the rotor first, hub bore was bigger than the rotor.)

If you look closely at the picture of my hub you can see the factory did not even machine the back side true with my front. The only thing it did was let some studs penetrate I few thousands farther, NBD when the drums on the front. I checked run out on my rotors with a dial indicator, after installitaion , and they were spot on.

[ICEMAN6166]

curious if there is any issue with the 9/16 studs and the holes in stock wheels

[FarmMotorSports]

For those that do this, please remember, no two castings are exactly the same.
The amount of machining done on each can be different.
Tolerance of the machining done varied depending on who ran the mill.
Our hubs were not made for rotors mounted on the back side.
The steering arms I cut up for spacers, happened to be within 4 thousands on the thickness varance .

What I'm saying is check your parts closely, just because mine were correct your's may be different.


And the 9/16 studs worked great on the wheels I have, split rims and E250 rims...
On a side note my one piece 16" (non-split rims) do not clear the caliper bracket, by about an 1/8".
So I guess I have a set of those for sale....

[Truckrat]

Pat, nice job on this! Been lots of folks asking about a "How to" on this one for a long time! Good to see someone come along and show how it is done!
Was good to see you at the Gypsum show, but where did you run off to?
I think we were doing the valve cover races when you walked up but I
lost track of you after that! Hoped you'd hang around a while and visit
with us! TR!

[charliemccraney]

See...WTH don't the f100 kits use ford calipers ...really bugs me..Ill do it eventually..and NO backing plates...not trying to hi-jack the thread though Nice job looks good

When talking about off-the-shelf conversion kits, the reason is the way the caliper mounts. The GM calipers bolt on which means a simple bracket can be used. Ford calipers use pins which require a more complicated bracket. Simple is cheaper than complicated and people generally prefer cheaper therefore, GM calipers are used in kits. As far as the actual function goes, there is no difference, so you get the same performance with a GM caliper based conversion for less money.

[aj64f100390-292]

See...WTH don't the f100 kits use ford calipers ...really bugs me..Ill do it eventually..and NO backing plates...not trying to hi-jack the thread though Nice job looks good

When talking about off-the-shelf conversion kits, the reason is the way the caliper mounts. The GM calipers bolt on which means a simple bracket can be used. Ford calipers use pins which require a more complicated bracket. Simple is cheaper than complicated and people generally prefer cheaper therefore, GM calipers are used in kits. As far as the actual function goes, there is no difference, so you get the same performance with a GM caliper based conversion for less money.

Well that part I got..Idk I guess I just like being able to walk in and order a ford part..and know its ford..because.then agian most people unless they knew they're cailpers brand designs...would kniw I suppose. so the f250s are easier? But in the end I may just suck it up buy the kit..lots of other things I need to work on other than that..

[aj64f100390-292]

hey , I was wondering what you used as a caliper bracket, I think I saw what you used , but i'm just being sure, what all are the differences? any pics.. dads got a suspicion that the f250 spindles are near identical to the f100 spindles...if they are then that would mean that i can get a 5 lug rotor the same diameter and use the cailpers, and i could have some more of those brackets you had made...Id like to see just how much is different...

[FarmMotorSports]

Post 7 shows the 3/8" bracket for the spindle.
I believe your asking about the "SEMI LOADED CALIPER ASEMBLY" includes caliper, anti rattle clips, slide pins, bracket that cradles the caliper , just add pads of your choosing. As seen in the first pick I posted.


I'm sure you could use these or other similar year (F150,Expedition,etc) semi loaded caliper assembly.
Pay close attention to off set of rotor, caliper bracket, Diameter of rotor the caliper was intended to fit, and the minimum rotor thickness the calipers were intended to work with...

As a side note where the attachment points are on the 'semi loaded bracket ' is a matter of which vehicle you tell the parts counter your buying for, caliper specs don't change all that much in a given weight class.

[jeepbut]

I am amazed that you figured all this out. Great job and thanks for letting us know about it.