BC847

I was recently talking with the wife about my wants as far as hopping up the heap. She never really looked away from the game she was playing during the conversation.

At one point she interupted mumbling "Can you make it stop?" Being sarcastic, I replied "Shoot! They make a rear disc conversion for it if ya want!"

She said "Fine!"

I said "Fine!"



This is NOT a "How-To" but more of an example of "What you're in for" thread.

There's substantial modifications and fabrication involved so if you have to ask instruction . . . . . lay down the wrench and step away from the truck.


Anyhoot, I'm working on the rear axle of a 1993 W250 CC with the typical Dodge OEM issue DANA70 axle with drum brakes.


Of course, start by removing everything. I just took out the four back-plate bolts and removed the entire drum brake assembly.





To replace the drum with a rotor, I had to remove the lugs without destroying them. I used one of the stupid Anti-Theft lug nuts to take the beating.





Here I've cleaned and painted the OEM axle bearing hub and am fixing to mount the rotor. It's from an '82 to '95 Ferd F250 diesel. As such it still has to have the hub hole enlarged to fit our mess. Further, the rotor's holes for the lug's heads must be enlarged to accomodate most of our trucks lugs. As part of the install, I had to mill the heads of my lug bolts to fit the rotor. Slotted/vented rotors are extra.





With cleaning/painting the assembly, new seals have the rotor/hub ready to install.

BC847

Now, after cleaning and painting the axle tube stuff, I first mounted the base bracket. This particular one allows one to mount the caliper in any number of positions to suit one's needs.





Then I installed the bracket that actually holds the caliper. Both brackets are of substantial plate-iron with a very fine cut and powder finish. High quality fasteners hold it all together.





Mounting the caliper is pretty-much straight forward. Apparently one can get basic calipers to work but I wanted the parking brake feature. I ended up with '76 to '77 Cadillac Eldorado calipers. I wanted all the associated cables and hoses to end up mounted high so as to be out of harms way. As such, these calipers are installed with the bleed ports on the bottom of the piston cylinder. I have to remove the caliper assemblies to bleed them properly. No big deal.
This design caliper requires a slot to be in the piston so as to key with a bump on the included pads. It keeps the piston from rotating in it's bore. If you mess with this kind, be sure to key the pads to the piston when installing.





Well, that was the easy stuff.


Naturally, the OEM bracket that came with the Eldorado caliper does not mate with the Dodge drum parking brake cable. Further, the current bracket puts the PB cable in the head of an adjacent bolt.
A trip to the local auto junk yard found a later model Eldorado bracket that moved the cable away for a better fit. I still had to modify it to fit this caliper though.
Then there's the thing about the Dodge PB cable sleeve's end. The one that plugs in the drum backing plate sideways. I ended up getting the PB cables off that same Eldorado.
With some aluminum duct-tape, bailing wire, and two 1/2" x 4" black iron nipples, I made PB cable sleeves that would fit a Dodge at one end, and a Cadillac at the other. Compare the end shown in the first image of this post, to that shown in this image. Works like a champ.





Because the caliper moves on it's mount, the associated hydraulic fluid lines must be such as to accommodate that movement. I used stainless steel braided lines for their firmness over the typical reinforced rubber type. Either way, one needs to come up with a firm mount for the flexible line's connection to the trucks ridged tubing. Using some 10 gauge C-angle, I cut and bent a bracket that is mounted by sandwiching it between the axle's spring mount, and the associated OEM lift block. It allowed me to place the connector and tubing, so that the caliper could still be removed for bleeding, without having to disconnect the flexible line.





Because the OEM drum brakes had the OEM hydraulic tubing connect directly to the OEM backing-plate, the OEM tubing was too long to connect to the flexible sections without having to wad up the tube(s). I replaced them with shorter lines so as to fit nice and purdy. I added extra mounts over the differential so as to keep the lines very secure. The OEM lines are wrapped in wire so as to provide protection. The extra mounts will help there but I also insulated the steel tubing from the mounts with some reinforced fuel hose. Works nice.





After replacing the master cylinder and front calipers with re-manufactured units, turning the front rotors, replacing all the brake system's flexible hydraulic line sections with stainless braided, flushing the circuit with synthetic DOT4 fluid, I can open my mouth and have spit hit the windshield with no more than two inches of pedal travel. A panic application has the rear wheels lock first with the ABS feature pulsing as it should.
The parking brake pedal locks the wheels in six clicks.

One of the first things I noticed was the truck doesn't nose-dive near as bad as before. Very sure-footed braking.





I like it.

I hope this helps those who're considering such an upgrade. Do your homework. Measure three times and cut once.



Thanks again to Dave (wannadiesel) for hosting my images.

alborada

Sweet!! looks nice When my brakes need redone I will do this mod!!

Micaiahfied

BC, did you get the mounting brackets in a kit? if so do you mind if i ask what they cost? also, if someone went without the parking brake would that take away most of the pain in the butt factor?

BC847

I got the so called kit from these folks ~ http://www.egrbrakes.com/ Glenn was very helpful. (They may run banners here in DTR, don't know for sure).

That without the parking brake is a little less expensive both in dollars and time. But it's still a pain in both respects, . . . . and I don't know that you'd save a whole lot by buying the parts local and fabricating your own brackets/etc if you consider time and aggravation an expense.

Nothing comes for free. I took the time to make sure the most important system on my heap works just like one would expect in terms of reliability and longevity. As such, it was a pain in the butt. I stretched it out over more than a week's time so as to approach each aspect with an open and patient mind. There were a number of "Got'chas" along the way.

Keep in mind: There is NO 100%, no questions asked, "Bolt-On" kit for our trucks that I know of. There's just no market considering the age of our line. With that one generally has to adapt calipers from the Eldorado, or a line of C-10 pick-ups (not sure there). The rest is making it work.

farmer0_1

looks good and solid, i like that.

Murf

Absolutely Beautimous, BC!

Awesome writeup and awesome pics, for dummies like me!

However, I do have a couple of questions!

1. What about proportioning valve changes? Ok, I'm not even sure our trucks have one. If not, might this warrant one?

2. Can you talk my wife into letting me do this as easily as you did yours?

gman07

BC,

Top-notch write-up, as always. I'm sure I'll find it useful once I find some more money

BC847

In talking with Glenn of EGR Brakes, he indicated the Eldorado calipers were a close match overall to our mess though I could expect an additional inch of pedal travel. As such, our OEM proportioning valve is OK for this application.
Before rebuilding this mess, I wasn't aware that I might have had brake problems if only worn pads and shoes. With essentially renewing the front, firming the hydraulic hoses with the SS braid, and adding this kit, my pedal is still greatly improved in terms of stroke length. If this set-up adds an additional inch stroke, I can't find it.
On that note, it's worth saying that these rear calipers are queer about bleeding and adjustment of the PB mechanism. With all the added parts in the piston/cylinder assembly, air has many opportunities to get trapped. I had to bleed mine four times after tapping the calipers with a hammer to dislodge any bubbles. The PB is self adjusting and as such this system DEPENDS on the driver regularly using the PB. It's basically a lever attached to a threaded bolt on the caliper's piston. It's connected by way of a cone type clutch. By design, it automatically tightens with excess slack over .030", When one apples the PB, it tightens. When one releases the PB (Preferably by the handle allowing the PB pedal to Snap up), the cone clutch slips back taking up any slack over .030".

If you don't use the PB, as the pads wear, the additional slack must be made up with the regular brake pedal (hydraulically) presenting as a longer stroke.


Pop-Quiz in five minutes.


Murf, I can't help you with your wife. Mine, I think she's messed up something really bad and I just haven't figured it out yet.


I am pleased that y'all fine this useful.

flyingd

I know I am going to have to do my rear brakes next year. I have a D250 and I was going to go with the 1 ton setup that I have heard about.

But tell me if you will... How much did it cost to do the disk brakes.

Jethrro

Gee thanks I just finished up the 1 Ton drum upgrade tonight. Jethrro

toyz

Very good info and pictures. Will this conversion work on a DRW?

ChrisLib

Once again, an outstanding and informative writeup! Your pics make it alot easier to visualize the extent of the mods. (really nice clean undercarriage BTW).

BC847

Unfortunately no, it's my understanding this set-up will not fit DRW. Don't know why.

I love my pressure washer.


Again, thanks y'all,

wannadiesel

There isn't enough room inside the dually rims for the caliper.