disc brake conversions?

[Gunworm]

I have a 1984 M1009 CUCV and my front left brake just went out on me. i think I finally wore the pad down too much. guess I should have checked it sooner when it started squealing...


I was thinking of maybe adding 4 wheel disc brakes, for better braking in case I ever decide to add a lift kit and bigger tires.

have any of you tried to do this before? anyone know where I can find any information on parts and installation and all that good stuff?

 

[JohnFire]

I know I looked into it a couple of years ago and it would have cost around $600-$1000. If I remember right they sell kits for doing the conversion. I think LMC had them. I had a tough time finding info for awhile.

 

[Dan6wd]

The good folks at ebay have what your looking for. There is a guy on there that sells the kit you need. You will have to buy front rotors from an 70's or 80's model chevy 3/4 ton truck and calipers as well. Type in 14 bolt disc brakes and you will see the parts.

 

[motormayhem]

I run 35's and have no complaints about the stock brakes.

 

[Dan6wd]

Virginia4x4 is the user, here is what he says you will need, in addition to his kit.
2) Rotors (1985 Chevy 3/4 ton truck front)
(2) Calipers (1985 Chevy 3/4 ton truck front)
(1) Set of brake pads (1985 Chevy 3/4 ton truck front)
(2) Soft brake lines (1985 Chevy 3/4 ton truck front, crush washers included)
(2) Banjo bolts (10mm, 1985 Chevy 3/4 ton truck front)
(1) Brake fluid

 

[mangus580]

The kits are VERY common for the 14 bolt rear axle. Not sure they are made at all for the 10 bolt axle on the 1009.

 

[kennyw]

Virginia4x4 is the user, here is what he says you will need, in addition to his kit.
2) Rotors (1985 Chevy 3/4 ton truck front)
(2) Calipers (1985 Chevy 3/4 ton truck front)
(1) Set of brake pads (1985 Chevy 3/4 ton truck front)
(2) Soft brake lines (1985 Chevy 3/4 ton truck front, crush washers included)
(2) Banjo bolts (10mm, 1985 Chevy 3/4 ton truck front)
(1) Brake fluid

You forgot to add the new axle in there... that kit doesn't fit the M1009. If you swap out the rear axle for a 14 FF (good way of getting lower gears for bigger tires anyway), then it is cheap and easy to do. I have tons of pics of my rear 14FF rear disc conversion that cost me about $100 to do with rebuilt calipers, used rotors and a free 14 FF.

 

[Bunkerbuilder]

There are two problems with the standard disc brake conversion that use the 3/4 ton brake rotors and calipers.

#1 the stud holes in the common 3/4 Ton rotor (.650 OD) are too large and will result in slop with the OEM studs installed.

#2 the rotor has no register to sit on IE when its installed it will not be concentric on the hub.

 

[kennyw]

There are two problems with the standard disc brake conversion that use the 3/4 ton brake rotors and calipers.

#1 the stud holes in the common 3/4 Ton rotor are too large and will result in slop with the studs installed.

#2 the rotor has no register to sit on IE when its installed it will not be concentric on the hub.

#1 When I did my disc brake swap there was no slop between the rotor and the stud. The studs have to be pressed into the rotor or they do not fit!

#2 The original drum I pulled off of the truck did not have a register to center the drum either.

 

[4bogginchevys]

oh man, I need info!

You forgot to add the new axle in there... that kit doesn't fit the M1009. If you swap out the rear axle for a 14 FF (good way of getting lower gears for bigger tires anyway), then it is cheap and easy to do. I have tons of pics of my rear 14FF rear disc conversion that cost me about $100 to do with rebuilt calipers, used rotors and a free 14 FF.

Would you consider sharing some info with me..........please! PM me if all is ok

 

[Bunkerbuilder]

A vendor on Pirate4x4 makes and sells a kit specifically for a 3/4 ton truck with 6 lug axles.

If Im not mistaken that is what a M1009 uses ?

From what I understand out of the kits he sells it would be either this one.
GM Rear Disc Brakes 10, 12, 14 bolt-Dana 60,70 and more

Or this one here.
GM Rear Disc Brakes 10, 12, 14 bolt-Dana 60,70 and more

You forgot to add the new axle in there... that kit doesn't fit the M1009. If you swap out the rear axle for a 14 FF (good way of getting lower gears for bigger tires anyway), then it is cheap and easy to do. I have tons of pics of my rear 14FF rear disc conversion that cost me about $100 to do with rebuilt calipers, used rotors and a free 14 FF.

I’m sorry I didn’t clarify the kit's I was speaking of that have a stud and rotor stud hole mismatch would be converting a 14 bolt rear differential (CUCV 5/4ths Ton Truck ) to disc brakes using the 3/4 ton Chevy front rotors and Calipers.

The Disc Brake conversion that I did to my M1028 was over 2 years ago hence I dont have the specs memoried but I do remember that the studs fell into the rotor holes and were not a press fit what so ever.

This is using the stock stud and without drilling out the hub to fit a larger dia stud that was large enough to be a press fit in the rotor.

If you like Ill gather the specs and better explain what Im talking about.

#1 When I did my disc brake swap there was no slop between the rotor and the stud. The studs have to be pressed into the rotor or they do not fit!

 

[kennyw]

Sure, what do you want to know? Did you look through the pics yet? I would rather post the info here so others can get the info as well.

Here is a link to the pics:
Picasa Web Albums - Kenneth - 1983 Chevy K20

Link to the $45 brackets from Ruffstuff (contact Gravel Maker on CK5 for the discount code) made from 3/8 A50 plate:
14 Bolt Disc Brake Caliper Mounting Bracket (Standard SRW) [6090031] - $50.00
Brake Caliper Brackets, 14 Bolt.....$45 for CK5 - CK5 Forums

The calipers and rotors are all stock GM parts from a 3/4 ton 4x4 front axle (they list '75 on the website but I purchased the parts for an '83 to match my truck and it all worked the same).

I posted more information in this thread (brake hose part #'s) but it looks like I need to fix the picture links:
14FF & Disc Brakes - CK5 Forums

 

[kennyw]

The Disc Brake conversion that I did to my M1028 was over 2 years ago hence I dont have the specs memoried but I do remember that the studs fell into the rotor holes and were not a press fit what so ever.

This is using the stock stud and without drilling out the hub to fit a larger dia stud that was large enough to be a press fit in the rotor.

If you like Ill gather the specs and better explain what Im talking about.

Was this on a Dana 70 or 14FF? My truck has a 3/4 ton 14FF in the rear (replaced the stock 14SF). The front 3/4 ton rotors use a 9/16" stud and so do the rear 3/4 and 1 ton 14FF's. I don't remember what the dually D70 rear axles use off of the top of my head.

But if he keeps the 6 lug 10 bolt, none of this will apply to him.

 

[kennyw]

Or this one here.
GM Rear Disc Brakes 10, 12, 14 bolt-Dana 60,70 and more

That would be the correct kit for the 10 bolt, but that is extremely over priced (for me)! For $350 I would upgrade the 10 bolts to 3/4 ton axles and add disc brakes to the 14FF.

Unfortunately, I just checked ruffstuff and didn't see a 10/12 bolt bracket though (they sell the 14FF brackets for $45). I would look around for another vendor as I am sure other vendors sell them.

 

[Bunkerbuilder]

Maybe that is where the difference lies, IE mine has a 5/4 ton or M1008 CUCV 14Bolt FF in the rear.

I used these GM wheel studs but used a dually one ton front rotor that had a smaller stud hole and drilled the holes out on the CNC for the correct press fit

GM WHEEL STUDS 3988538.
If you compare the 3/4 T rotor with the stock chevy studs you will find a gap of about .025-.040 between the stud knurl and the ID of the stud hole.

I also used new Rear Wheel HUBS GM part # 3977397.

I have a load of figures when I did all this but its not on my desk at the moment as that was 2 years ago. Tons of other info cluttering my desk at the moment.

I still plan to use another design that Im working on, on another CUCV but that project will use a 4 piston wilwood caliper and a braket that solid mounts the caliper to the axle flange.

Here is my 14 bolt disc brake conversion.
I used all 1 ton parts mainly just to see if I could do it....I also was not pleased that the 3/4 ton kit had problems with both the studs and the fact that the rotor did not have any place to sit on the hub.
I solved these problems using 1 ton dually rotors and a machined ring that fits between the rotor and hub. and as you can see I made a spacer to take up the gap between the axle housing and the caliper bracket.
also here is a list of GM parts I used for anyone that wants to know what they are.
3977397 HUBS Rear Wheel
9428908 GM INNER BEARING & RACE
15702309 HUB SNAP RING
7451928 GM OUTER BEARING & RACE
9436881
ROTORS 1985 Chevy front dually
CONCENTRIC RINGS MACHINE SHOP
3988538 GM WHEEL STUDS 16
469694 SEAL
15665667 CALIPER
15665668 CALIPER
BENDIX PADS
Caliper bracket 1985 Chevy Dana 60 right and left sides
12338037 CALIPER LOCK BOLT
14023437 SPRING
14023439 KEY 2
462813 SHIELD
462814 SHIELD
341509 Spindle nut
12471641 Axle gasket

Brake lock I used MICO, Inc. : Innovative Braking and Controls Worldwide

20 lbs each before.
http://i80.photobucket.com/albums/j184/mag-lock/7x134_500.jpg

10 lbs each after.
http://i80.photobucket.com/albums/j184/mag-lock/7x134after2.jpg


Pic Below is mocking up the rotor / caliper to know how thick the adapter needed to be.
http://i80.photobucket.com/albums/j184/mag-lock/14BOLTCORP1.jpg

http://i80.photobucket.com/albums/j184/mag-lock/14BOLTCORP2.jpg

http://i80.photobucket.com/albums/j184/mag-lock/14BOLTCORP3.jpg

http://i80.photobucket.com/albums/j184/mag-lock/14BoltLeftbare.jpg

http://i80.photobucket.com/albums/j184/mag-lock/D60CBRACKETINSTALLED2.jpg

http://i80.photobucket.com/albums/j184/mag-lock/14BoltSpindleAdapterLeft.jpg

Was this on a Dana 70 or 14FF? My truck has a 3/4 ton 14FF in the rear (replaced the stock 14SF). The front 3/4 ton rotors use a 9/16" stud and so do the rear 3/4 and 1 ton 14FF's. I don't remember what the dually D70 rear axles use off of the top of my head.

But if he keeps the 6 lug 10 bolt, none of this will apply to him.