craigsix

my 2012 rcsb lsworktruck came with rear drums. i heard i can put a 15" wheel on there. wish i would of known that before i got 2 fly spare tire rims with 265/65/17 bfg long trail tour for the track. anybody with discs interested in them? 30.6" tall runs with stock programming.

GMCtrk

iTrader: (27)

Does anyone have a slightly more detailed write up on this swap? I want to do this myself. Anyone know if you can buy the complete drum setup ready to bolt on?

charlie_gonzales

iTrader: (11)

Is it the same for going drum to disc? Just the opposite though? I heard there was a valve or something that was needed. I'd like to step up to disc brakes in the rear of my 06 crew

1FastBrick

iTrader: (17)

It is the same as mentioned above. The only difference is the way the flange is clocked on the rear axle. The Brake stand off from the axle face/wheel mounting surface to that brake flange is the same distance between the 2 housings.

I believe the proportioning for the brake bias is in the Master Cylinder.

You could put an inline adjustable Proportioning valve on the rear to adjust the bias when swapping from Drums to Disc.

When you look up a Master cylinder for say an 05 silverado With a 6.0 it
list several options depending on application. 05 was the only year you could get an SS Silverado truck with AWD disc/disc or 2WD disc/drum.

JC4 BRAKE VAC POWER, DISC/DISC, 7,200 LBS
JF3 BRAKE VAC POWER, 17″ DISC/DRUM, W/ABS, 7,000 LBS
JF7 BRAKE VAC POWER, 17″ DISC/DRUM, W/ABS, 6,400 LBS
JL6 BRAKE SYSTEM MAN, FRT DISC, RR DRUM, CAST IRON
JH6 BRAKE HYD POWER, 4 WHL DISC, 9,900 LBS

I believe these options would apply to a regular 1500 not an HD with HYDRO Boost.
JC4 would be an SS AWD 4.10 disc/disc
JF3 would be a standard 4x4 4.10 disc/drum
JF7 would be a standard 2WD 3.73 disc/drum

GMCtrk

iTrader: (27)

Does anyone actuslly have stepwise instructions on how to swap the drums? The axles need to be pulled out to seap the backing plates?

1FastBrick

iTrader: (17)

Yes, axles have to be pulled out to swap the backing plate.

Jack Truck up.
Remove tires.
Remove caliper and brackets.
Remove disc.
Remove rear diff cover.
Pull Differential pin and remove C-clips holding axle.
Pull axle.
Disconnect rear brake lines including Parking brake cable.
Remove 4 bolts holding disc brake backing plate assembly on.

Install drum backing plate assembly and tighten 4 bolts holding assembly.
Modify disc rear brake lines to hook up to drum set up or install original drum brake lines.
Install drum brake parking brake cables.
Install axle's.
Install C- Clip to hold axle and differential pin with bolt.
Install cover and add gear oil.
Set/ adjust your brake Shoe's for the drums.
Install drums.
Install rim.
Check master cylinder fluid level before bleeding brake system.
Bleed brakes to remove all air. Check master cylinder fluid level during and after this process.
Clean up mess.

Test to see if they function properly and make sure they are not leaking before taking on a road test.

GMCtrk

iTrader: (27)

1fastbrick, that seems pretty straightforward. Thanks for the instructions.

Do you know if it is possible to buy the entire drum assembly ready to bolt on? And then all I would need would be the backing plate and e-brake cables?

1FastBrick

iTrader: (17)

Not sure. You would have to contact the dealer or buy a used assembly.

15911567 is the drum backing plate for 05-07 from what I found but they're not cheap...

Maybe source it from the aftermarket for less or buy a used assembly.

I have seen complete drum axle assemblies go for as low as $100-$300 depending on gears and milage on craigslist.

dfarr67

Old thread...but, what is the dimension between axle face and face of mounting flange. I want to confirm about 73mm.

Classicham

great idea... i need to do this