Rear disc brakes

[skysix]

I have seen a bunch of threads on the ElDorado rear disc ebrake conversion for the 14bolt, but am looking for something a little different. Unsuccessfully so far.

What I would like to do is use the same rotors as the front D60, as well as 2 sets of calipers, so I would have a hydraulic parking brake (with a locking valve) that could also be used as an emergency brake if the primary brake system craps out. A completely separate circuit with its own master cylinder attached to the park brake pedal.

An added advantage for an expedition vehicle would be commonality of rotors and pads, less spare parts to carry and in a pinch could swap the p/e-brake pads to the front. and limp in to the next parts shop or wherever the replacements could be DHL'd to.

Anyone know who might do something like this? I seem to remember seeing a buggy somewhere that had dual disc calipers on the rear axle. "Cutting" and normal brakes I suspect.

And on a related note, how hard is it to get 8 lug rotors for a Kodiak 4500 front/rear and mount them on a D60F and D70HD rear? The LAV/Stryker wheels I am using have the same bolt pattern and adding an 8 bolt medium truck to light truck GM 8 bolt adapter plate adds a lot of weight and width and potential complications.

 

[Chaski]

If you want to do something a little different you could go with the newer GM 10.5" AAM axle housing. They have factory disk brakes with internal mechanical drum parking brakes inside the disk hats. They use the same carrier / ring & pinion / bearings (except for one pinion race) as the 14 bolt.

Don't quote me on this but I think they can be found in 99-06' Chevy 2500 pickups without a Duramax.

Last year I swapped the gears and locker out of a M1008 and put it in one for a co-worker. Turned out clean, and the parking brake is decent.

 

[LT67]

If you want stopping power, stick with the drums on the 14ff....

 

[blueblaze]

As a person who has done the usual disc brake swap with the front chevy calipers and then swapped to the eldorado calipers for an ebrake after a nv4500 swap, it really wasn't that bad. Although I see most kits use the later 70s and 80s eldo calipers, I have the early 76 style calipers and they honestly work mint after you understand how they work. The key to them is always using the parking brake as that is what adjusts the caliper. This is why I think alot of guys trash them, that and also the price of them if you have no core. I have a rock hard pedal and my ebrake holds the truck on any steep incline. As for a completely separate braking system, I think that's way over complicating things and going into the custom fab. You state you want ease and parts availability if an issue is had over the road. If it were me, also assuming your using a M1031, I would use the normal chevy calipers on the rear and use a driveshaft parking brake on the 205 rear output. The other advantage to this is if you have the truck in 4wd, you'll have all 4 wheels locked up, which is great if your on a slippery hill and 2 wheels just won't hold the truck. It's also mounted up high and out of the way. But honestly if I were to do it all over again with my M1008, I would've just stuck with the drum brakes, its cheaper and easier to operate and considering the production run, parts are cheap and everywhere.

 

[Sharecropper]

When I acquired my M1028 in 2010, the rear brakes were grabbing and locking up bad. My mechanic pulled the hubs and discovered severly defaced drum surfaces, so bad that new drums and shoes were going to need to be installed. The costs for repair were estimated to exceed $700, so I began to research rear disc conversions. I settled on the kit offered by TSM Manufacturing in Castle Rock, CO. Their kit included completely rebuilt 1977 El Dorado calipers wirh emergency brakes and everything necessary for installation including flexible stainless steel lines. I did a write up on SS here -

https://www.steelsoldiers.com/showthread.php?52121-Rear-Disc-Brakes&highlight=

The kit was easy to install and works like a charm. The existing emergency brake cable worked without modification, only had to bypass one of the alignment rings on the frame to provide sufficient length. My truck will stop on a dime going forward or backward, even after fording a creek when everything is wet. I really can't see why anything else would be needed. I respect the OP's desire to build a stronger system, however I will agree with blueblaze, the best way to hold the truck on a hill would be to add a driveshaft parking brake on the 205 rear output. If my truck had the NP205 instead of the NP208, I would definitely install the driveshaft parking brake kit.

I will add one more thing - That darn rear brake proportional valve affects how much brake pressure is sent to the rear wheels. If the valve becomes out-of-adjustment, either the rear brakes will grab quicker (which is what it is designed to do under load) or there will be insufficient line pressure to the rear brakes. Post #40 in the thread link above explains how the valve should be clocked in order to be adjusted correctly. For those who are not aware and are so inclined, GM issued a bulletin in 1988 to remove and discard the thing. 88-320-5 removes the valve entirely and replumbs the rear lines so that the line pressure to the rear brakes is unaffected by any valve which can become out-of-adjustment. After I became aware of 88-320-5 and removed the rear proportional valve from my truck, I tested the brakes several times in an emergency stop scenario from 30 MPH and all 4 tires locked equally with 4 equal skid marks every time I initiated the test.

Also, it is not an emergency brake. It is a PARKING brake.

Hope this helps.

 

[Ilikemtb999]

If you want to do something a little different you could go with the newer GM 10.5" AAM axle housing. They have factory disk brakes with internal mechanical drum parking brakes inside the disk hats. They use the same carrier / ring & pinion / bearings (except for one pinion race) as the 14 bolt.

Don't quote me on this but I think they can be found in 99-06' Chevy 2500 pickups without a Duramax.

Last year I swapped the gears and locker out of a M1008 and put it in one for a co-worker. Turned out clean, and the parking brake is decent.

My new body style 07 2500hd has the same axle. I've been trying to find myself a set of backing plates from one so I can figure out how to mount it to my 14bff.

Im currently running 3/4 ton calipers on mine but would like something with an emergency brake.

 

[camok5]

Si c'est ce que vous recherchez, double étrier de frein

http://www.pirate4x4.com/forum/general-4x4-discussion/911859-14-bolt-e-brake-disc.html

http://www.pirate4x4.com/forum/general-4x4-discussion/507305-bad-spacing-14-bolt-disc-brakets.html

http://www.tsmmfg.com/2630EX2.htm

 

[Obijuank5]

guy on ck5 and pirate "NVRENUF" did it with stock chevy d60 calipers and brackets on a d70hd which uses the same backing plate flange.