Disc Brake Engineering Thread

[gringeltaube]

...... disc brakes with TWO calipers on EACH front wheel .....

Just saw this last weekend at the Unimog museum in Gaggenau...

G.

 

[blackrock]

Looks good do you make the brackets?

Yep those brackets were cut on a water jet.

 

[spicergear]

Just saw this last weekend at the Unimog museum in Gaggenau...

G.

Yep! The system is a dual circuit but the one side of the MC pushes fluid to one set of front caliper and the rear calipers and the other side of the MC pushes fluid to the other set of front caliper. Front set or rear set on front axle...not set on one side or the other. Like you have ALL the brakes...then more brakes.

 

[mudguppy]

Now we need to find the front rotors and start discussing how we might go about making it happen.
Judging from his posts, mudguppy is very happy with his, so if you're impatient or not handy with tools
you might want to save up and buy from the guy at diff eng.

Edit: Believe I've found the front rotors.

Front Rotor info: Rockwell wheel brakes w/ pics - Pirate4x4.Com Bulletin Board
User: DriveTime from Pirate 4x4

Off of front 1994 Ford Truck F700
NAPA Part #: NB 4886056

From NAPA:
Attributes: # of Bolt Holes : 6
Bolt Circle Diameter : 8.75"
Brake Rotor Diameter : 15.39"
Brake Rotor Discard Thickness : 1.42"
Brake Rotor Thickness New : 1.54"
Brake Rotor Type : Disc Brake Rotor Only
Center Hole Diameter : 6.45"
Height : 6.03"
Maximum Lateral Runout : .004"
Mounting Type : Type L - Rotor Only. The Rotor Is Mounted Inboard Of The Hub. The Hub & Rotor Sections Are Bolted Together. Replace The Complete Assembly If Hub Flange Is Bent Or Damaged. See Diagram For More Information.
Vented / Solid : Vented

i went out and looked yesterday - i can't find a PN stamped anywhere that is still visible. the rotor pictured sure looks correct, but...

i know that the inboard rotor edge has been machined (chamfered) quite a bit to clear the knuckle steering arms. i remember from talking with Steve early on that the hub flange may need to be machined as well. from what i saw yesterday, the hub flanges look to be OE thick, but i think the top hat flange of the rotor may have been machined. so, these two machinings combine with the thicker races seem to be the three things necessary to fit the rotor, clearance the knuckle, and still allow room for the caliper brackets.

just my observations and presumptions.

however, as i stated in the other thread, i do know that Steve machined and hardened the mounting brackets at the kingpins. this is important for long life under the front end of a heavy truck... not so much for a rock crawler.

 

[tm america]

good info thanks for posting

 

[blackrock]

Just some food for thought. Using the f350 calipers on the front instead of using the f550 makes the brackets longer and has more bend in the bottom bracket. If you notice on steves brackets the huge gusset he has support the bottom bracket after being bent. Also, think this was covered but you need to grind the saddle quit a bit on the caliper on the f550. Just info for the at home builder.

also the part number i always used for the rotors is RAYBESTOS Part # 8520.

 

[oddshot]

Really need to find an upgrade for the master cylinder/booster set up too.

A big ol' hairy PLUS 1

For my use I think a master cyl upgrade would be about all that the Deuce needs. I don't haul or tow anything real heavy with the Duck ... the brakes seems to up to the job I need done ...

But I sure would like the security of a second circuit!!!!

A SAFE RELIABLE CHEAP (in that order) m/c up grade has been sort of a "holy grail" for me.

I am curious about this line:

"a master cylinder from a 1985 Chevy K30"

Has anybody got any experience with this?


oddshot

 

[frodobaggins]

Subscribed. Really need to find an upgrade for the master cylinder/booster set up too. Jim

A big ol' hairy PLUS 1

I've started a separate engineering thread for this issue now. Please let's try to use that one to give each topic the attention and clarity it deserves

http://www.steelsoldiers.com/deuce-...46-dual-circuit-brake-engineering-thread.html

 

[frodobaggins]

also the part number i always used for the rotors is RAYBESTOS Part # 8520.

Raybestos 8520 crosses to rotors that look like the first ones.
Raybestos 8517 crosses to rotors that look like the second ones.

Hmmm, yours look like the second ones. Food for thought, let's dig deeper.

 

[frodobaggins]

Mudguppy has granted permission for me to use his pics in this thread, so here they are:

 

[frodobaggins]

First post(s) updated with some more part numbers.

 

[frodobaggins]

Longer studs:

Meritor Part #: R005871R & R005871L
NAPA Part #: TWD WA2332 (Right) & TWD WA2333 (Left)

From NAPA:

Attributes:
Wheel Stud Application : Headed Disc Wheel Studs
Wheel Stud Body Diameter : .973" - .977"
Wheel Stud Knurl Diameter : .998" - .1006"
Wheel Stud Length : 3 3/32"
Wheel Stud Material Grade : 5
Wheel Stud Shoulder Length : 1 3/8"
Wheel Stud Thread Length : 1 1/4"
Wheel Stud Thread Size : 3/4"-16

 

[blackrock]

I think i know why he uses different rotors in the rear. IF you look the two rotors are two different widths/ lengths. The one is .8longer. Using the longer ones in the rear puts the caliper closer to the original brake mounting plate, making the bracket smaller. So you could use either rotors in the rear but have to make the correct bracket to the rotor. Im thinking of offering both, just including a spacer .8". Kyle

 

[mudguppy]

... Also, think this was covered but you need to grind the saddle quit a bit on the caliper on the f550. Just info for the at home builder. ...

not sure what you mean here - please elaborate since no grinding was required and none of the calipers were 'ground' or machined...

 

[blackrock]

not sure what you mean here - please elaborate since no grinding was required and none of the calipers were 'ground' or machined...

ill try to find some pics. but you have the f350 calipers in the front if im not mistaken right? The f550 saddle that the caliper mounts to hits the knuckle (on the front) and to get full contact of the brake pad it has to be ground/machined down to allow the pads to make full contact with the rotor. Kyle

 

[mudguppy]

F550's at all 4 corners.

 

[blackrock]

this isnt the best picture but it shows the saddle that holds the brake pads and where some grinding had to be done. Now this pic is of the rear axle i couldnt find a good pic of the front set up with the saddle. Mudguppy, do you have any pics of the bottom side of your saddles? or do you remember how close they were to the front knuckle when installing them? The area of grinding is the width of the saddle x 2" long and maybe .125 deep.

Kyle

p.s ill keep looking for a better pic

 

[blackrock]

not sure what you mean here - please elaborate since no grinding was required and none of the calipers were 'ground' or machined...

Ask and you shall receive. factory is straight with no radius. ill post a pic of a factory one when i get home. Kyle

 

[blackrock]

again not the best pic but you can see it is flat

 

[m-35tom]

i am not sure what you gain with disk brakes on a truck like this. the shortcomings in braking are not so much the drum brakes, but the booster and the low pressure it generates. my re-engineered brake systems have all had stock brakes at the wheels, but you can lock them easily with one finger on the brake pedal. the other half of the brake system needs to be done first, and then i doubt anyone would want disk.

tom