DISC BRAKE COVERSION

How do we feel about converting the rear axle drum brakes to disc brakes and what would be the best kit to buy?

P.S. Is this only limited to 1/2 tons? (LMC only sells for 1/2 ton applications)

 

I know its popular on the 14 bolts in 3/4 and 1 tons. I honestly feel it is much more appropriate and worthwhile in the 1/2 tons. The 14 bolt drum brakes work awesome, but are pretty heavy. I think the whole axle is something like 800lbs though, so saving a few hundred going to less functional brakes probably doesn't do much for a daily driver. If you are just trail running it then sure.

 

I did a rear brake conversion on my K20. My rear drums had filled up with mud a few times from water crossings, and since I don't have a good crawl ratio some of the trails I went down I had to ride the brake the whole time. Once drums get hot they won't cool down for a long time.

Disc brakes fixed those issues- but still aren't perfect for me. Had issues with the rear brakes wanting to lockup before the front ones. Ended up having to add a manual brake proportional valve to the rear.

I also no longer have a parking brake.

 

I converted to rear discs with Cadillac calipers. I then replaced them with 3/4 ton front calipers and lost my parking brake. I then converted back to drum rear brakes - 13x3.5 and was happy as a clam and got a parking brake back!

 

ORD does now have the caliper kits with parking brake. They didn’t used to.

 

I don’t wanna give up my 15” rims. Otherwise I might have considered it.

 

You can cut holes in the backing plate with a hole saw,to let dirt, mud and water escape the from the drums on off-road rigs.

 

I like my disk brakes.Brake jobs are much easier,much faster.I like wrench on squarebody trucks,but drum brakes is not one of my favorites.

 

not a bad idea and not a bad rig (your driveshaft is missing haha)

 

All this is my opinion and you can tell me to suck it if you like. Half of the cars/trucks I build I do rear conversions, but only if it adds up.

Other than wet environment there is almost no benefit on the rear.

Pros:
Easier to change pads then drums

Possible braking improvement but since your rears do about 30-40% of the braking and unless you are upgrading to a 14" rotor and 4-6 piston $3k rear set-up, you'll only get a maybe a 10-20% over a drum, the net return will be maybe, maybe 3-5% better. Only in the right environment. If you tow, you'll overheat a small pad much quicker than a large shoe.

Cons:
Ineffective parking brake on most set-ups.

Rear disc suffers from knock back issues unless it's a full float. Have to drag or pump brakes to keep pad to disc if road racing.

Reduced gas mileage. Disc brakes usually outweigh drums when you add up bracket, calliper, rotor. Increased unsprung weight and more rolling resistance as pads frequently in contact.

Increased lining changes. How often you change shoes vs. Pads? I would bet 2-3x as much.



Racing-yes
Off-road only-yes
Rain every day and you don't know how to pump-yes

Daily driver-no

If it's a 1/2 ton. Better return is the larger 1/2 ton drum set-up. Increased performance without all the hassle. Cost $50-100 at junkyard and another $100 for all new parts for it.

 

it was,not no more,and thanks!

 

Maybe disks weigh more on a 1/2 ton axle,not sure,but I know I’m about 75 lbs lighter on the full float 14 bolt with out drums...

 

that's a heavy duty looking driveshaft dude

 

I agree and with 14b FF every part is heavy so switching to discs makes sense. Also, the rotor that is swapped is larger than what is used on the 1/2 ton. But I haven't seen a caddy caliper set-up that I trust with the parking brake. The stock pedal simply does not take up enough movement in the cable. Adding a ratcheting handle or an e-stopp makes it safer.