Need some brake tech info

Granny

Granny

One day at a time...
Joined
Jun 12, 2007
Location
Cabarrus County (Rimertown)
Over the past couple years I have found myself towing more on steep, curvy mountain roads than I ever did when I was wheeling. Although my camper weighs less than half of what I used to pull when wheeling I am at times working my brakes harder than I ever did. I have, at times, pulled off the road to let the front brakes cool. It seems as if the rear drums on the truck just aren't doing their fair share of the work, and, for the record, the trailer brakes are working. I am wondering how much, if any, I would gain by converting the rear brakes to disk, and what is involved in doing it. I will also mention that the rear drums and shoes are in good condition and they are properly adjusted.

Does anyone out there have any experience with this type of conversion? ThanX in advance! :)

Subject vehicle: 1992 Dodge D250 (2WD), Cummins w/ auto trans, Dana 70 rear diff
 
Calling @GubNi

I say go for it but I've only dealt with trail rigs.
 
Also try ebc yellow stuff pads on front with some drilled and slotted rotors. I noticed a huge drop in fade as well as better braking performance.

It's all about surface area of the pad/shoe and pressure applied. Disc usually apply greater pressure with smaller surface area.

Other than rear discs, also look at hydro boost conversion to get the pressures up higher.

A good start would be to check current brake pressures at the caliper/drum bleeder screws. This will let you know if all the current parts are operating at optimum levels.
 
Don, I switched to Power Stop rotors & pads, from 4 Wheel Parts, on my Silverderado. Being that Most Chevy 1/2 tons, never had decent brakes, Power Stop, Did make a difference. There's is also new brakes on the rear, but as usual, the rear brakes barely touch! Maybe an adjustable proportional valve, would get you some rear brake! Rear disc, will probably be the same, > going to depend on the porportion setting.
And for disc info, what rear diff are you running?
 
Are the rear drums properly adjusted?
 
shawn said:
Are the rear drums properly adjusted?
Click to expand...

That's what I was thinking.

Over the road trucks still use drum brakes because they can be built to stop very heavy loads in a smaller space than what a similar disc brake would require. They just make the drums wider. Your D70 should have sufficient rear drums to handle anything the truck was rated to tow.
 
Then he should check them again.

My truck has great big rotors on the rear axle, and they are the first ones to get hot. If the drums aren't getting hot, they're not working.
 
Temperature will tell you how well the brakes are working at each wheel. I like to use a point and shoot infrared thermometer. I think my 97 2500 has about the brake set up as yours and I tow 9000lbs back and forth to Harlan without a problem. I did upgrade to EBC pads and rotors and that made a definite improvement. Break in or bedding procedure is important.
 
Appreciate the replies!!!.. and now rethinking on the brake adjustment. Sometimes I just can't see the forest for the trees.

When I first got the truck it had an open differential. The wheels were easy to spin, thus the brakes were easy to adjust. I could "feel" what I was doing, and I do remember the brakes worked OK. However, after putting a limited-slip in it a few years ago the brakes suddenly became hard to adjust as that "feel" was no longer there due to all the resistance from the drive line. It became hard work combined with guess work. I just discovered a post on DTR (Diesel Truck Resource) that may turn things around for me, and I feel a little stupid for not thinking of it myself. The poster simply removed the bolts from the flange of the floating axle and pulled it out just enough so it wouldn't drag on the hub/drum, thus making the wheel easy to spin and "feel". He said he lost a little bit of oil, but the brakes were a snap to adjust. So based on that info, I am thinking if I jack one side up at a time and wait a few minutes to allow the oil to drain back toward the diff I probably won't lose any at all, and I will once again be able to adjust my brakes to where I know they are right.

Now another brake question for you fellows. A local mechanic (pretty good one) recently told me that pumping the emergency/parking brake pedal should adjust the rear brakes for me. I have never had much faith in the self-adjusters. I have also always believed they were activated by hitting the brake pedal while moving in reverse. What are your thoughts on this?

Again... appreciate the feedback! :beer:
 
I would say that without spending a good chunk on money, you will loose your parking brake going to discs. Easiest/cheapest option for going that route would likely be to find a d70 from a newer dodge and swapping in your LSD/gears. Another option might be to look at an exhaust brake, but also not a cheap option.
 
Pump brakes while backing up will engage self adjusting drum brakes.
 
Just remembered-used to turn adjuster tight or as far as possible and then back off 6 or 7 clicks. That made sure everything got seated.
 
moldman05 said:
Just remembered-used to turn adjuster tight or as far as possible and then back off 6 or 7 clicks. That made sure everything got seated.
Click to expand...
Yep. When I do drums I'll adjust them out then pump the pedal a few times to seat the shoes and repeat.

I'd try readjusting the shoes to see if that helps. If you want to swap to disc anyway I'd look into an axle swap or Bolton on newer d70 discs with the drum park brake instead of an aftermarket swap with Chevy calipers like on a wheeling rig. That'd be the easiest way to keep a parking brake.
 
The original intent of this thread was to gather some info and ideas, and you fellows have done me right... as always. ThanX!!! :beer::beer::beer:

If the disk brake idea/plan was a go, I was going to start scavenging up what I needed over the winter, and plan on having a spring project. Now, I think I will just wait and try out the newly found trick of removing the axle bolts to get the rear shoes adjusted properly, and then see how things work out. The truck won't be going very far before spring anyway, and, truthfully, I would much rather go fishing in the spring than work on a project! :)
 
Auto-adjusters work until they don't.

What I've seen in the past is that the screw threads get goobered up with brake dust or rust or whatever and quit spinning on their own.

If you go to a late-model setup with discs and a pair of little parking brake shoes inside the rotor, you'll get to crawl under the truck every six months to dial the parking brake shoes out another few notches. (Because they don't have any way to auto-adjust and - inexplicably to me - still find a way to wear down over time.)
 
XJsavage said:
Calling @GubNi

I say go for it but I've only dealt with trail rigs.
Click to expand...

Sorry about the delay. @shawn can you see why I got an alert, but not and email please?

Your problem definitely seems like rear brakes not working and it's over working your front brakes. I also had similar troubles and that's what led me to start selling disc brake kits. I bet if you adjusted your rear brakes it would work good for a little while. Your drums might be out of spec also. A disc conversion would mean you never have to worry with it again. www.lugnut4x4.com
 
something else to check would be the rear brake hose. brake hoses swell internally over time, restricting the flow of fluid, but still look fine from the outside.
 
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