DISC BRAKE COVERSION

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Frankenchevy

Proverbs 16:18
Joined
Jan 3, 2018
Posts
5,904
Reaction score
7,249
Location
USA
First Name
Jeremy
Truck Year
Square
Truck Model
CUCV
Engine Size
Small
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.
There’s no way my 14ff cucv brakes outweighed my disc conversion. All of the disc components are less than half the weight of my drums alone.

edit: now I see you’ve already addressed this point.
 

Rhett Croley

Junior Member
Joined
Feb 25, 2020
Posts
20
Reaction score
40
Location
Augusta, GA
First Name
Rhett
Truck Year
1990
Truck Model
K5
Engine Size
496
I have them on a 14ff and two 14sfs. They look great but not worth the trouble. I have lock-up issues on the rear after changing to hydro boost, even with the prop valve turned all the way down on the 14ff. The 14sf has el dorado calipers and they were a **** to bleed and set up and I beleive they are the reason for the pulsation I feel in that truck's brakes. My research through indicates is that this is common and I'm going to have to go to half ton front calipers instead of el dorados to make it stop.
 

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
3,935
Reaction score
5,685
Location
kansas
First Name
Rick
Truck Year
1975
Truck Model
c20
Engine Size
350
Was that title supposed to read disc brake coercion?
 

84 M1008

Full Access Member
Joined
May 11, 2018
Posts
363
Reaction score
197
Location
New York
First Name
Wayne
Truck Year
1984
Truck Model
M1008 K30
Engine Size
6.2 diesel
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...

I did the conversion on my M1008/K30 and there was no way the disc conversion out weighs the gigantic drums on that truck.
 

LSX K10

Junior Member
Joined
Jan 19, 2021
Posts
17
Reaction score
28
Location
Brandon, MS
First Name
James
Truck Year
1986
Truck Model
K10
Engine Size
Ls 5.3
You must be registered for see images attach
You must be registered for see images attach
I did a conversion on the rear of my 86 k10 from Little Shop MFG using wilwood calipers and drilled slotted rotors. Love it so far but haven’t finished the truck yet. Here’s a pic of front and rear
 

Keith Seymore

Full Access Member
Joined
Jul 13, 2015
Posts
2,608
Reaction score
8,014
Location
Motor City
First Name
Keith Seymore
Truck Year
1987
Truck Model
R10
Engine Size
4.3L
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.


As a former brake engineer for GM Truck (and having given this a lot of thought): That's kind of where I'm at.

The rears are throttled down via the proportioning valve. If one needs more rear brake, why wouldn't you just kick up the line pressure to the rear?

Otherwise, putting discs on is like putting in a bigger motor to overcome a 2bbl carb, at least the way I see it.

K
 
Last edited:

Bennyt

Full Access Member
Joined
May 17, 2019
Posts
1,018
Reaction score
1,397
Location
Surprise
First Name
Ben
Truck Year
1977
Truck Model
C10
Engine Size
350
For those of you do decide to put discs on the rear on lifted trucks, I prefer to mount them upside down with the bleeders facing down. You'll have to bleed them off the truck with a piece of wood in the caliper, but you'll be able to run the parking brake cables over the axles for better ground clearance possibly eliminating cable extensions and or custom cables.
 

BBBURB

Full Access Member
Joined
Jun 26, 2019
Posts
77
Reaction score
82
Location
Anaheim, CA
First Name
Zeke
Truck Year
1989
Truck Model
R2500 Suburban SLS
Engine Size
454 7.4L
My back brakes where not working at all. They were leaking, the axle seal was bad, they needed a complete overhaul. I said to myself, I am not overhauling this trash. If I am going to spend my precious time on getting some rear brakes working its going to be upgraded. Also im in California where "brake checking" happens every mile or so. It took me about 3 days to do this job. It was a total PITA but Im happy now. I stop on a dime. I opted for the giant caliper rather than the Cadillac Caliper with e brake. Im telling you, I can stop on a dime. Very happy. Product from Lugnut 4x4 who was very supportive by email when I had some install problems not related to his product. I do need to dial down the brake pressure so it doesnt overpower the fronts. But im enjoying it for now as is.



You must be registered for see images attach
You must be registered for see images attach
You must be registered for see images attach
You must be registered for see images attach
You must be registered for see images attach
 

BBBURB

Full Access Member
Joined
Jun 26, 2019
Posts
77
Reaction score
82
Location
Anaheim, CA
First Name
Zeke
Truck Year
1989
Truck Model
R2500 Suburban SLS
Engine Size
454 7.4L
For those of you do decide to put discs on the rear on lifted trucks, I prefer to mount them upside down with the bleeders facing down. You'll have to bleed them off the truck with a piece of wood in the caliper, but you'll be able to run the parking brake cables over the axles for better ground clearance possibly eliminating cable extensions and or custom cables.

The reason the bleeders are supposed to be at the top is because air bubbles rise up. It makes it easier to bleed the brakes and not have trapped air bubbles.
 

Curt

Full Access Member
Joined
Sep 11, 2017
Posts
676
Reaction score
1,140
Location
Loco Hills
First Name
Curt
Truck Year
1984
Truck Model
K-30
Engine Size
383
The reason the bleeders are supposed to be at the top is because air bubbles rise up. It makes it easier to bleed the brakes and not have trapped air bubbles.

I believe he knows,just trying to give out pointers to help with ground clearance and protect the parking brake.
 

Powerhouse Ranch

3G Connoisseur
Joined
Jan 6, 2021
Posts
1,453
Reaction score
2,516
Location
PA
First Name
Luke
Truck Year
1980 & 1988
Truck Model
C25 & V15
Engine Size
454 & 350
The reason the bleeders are supposed to be at the top is because air bubbles rise up. It makes it easier to bleed the brakes and not have trapped air bubbles.

Always remember that! haha learned that the hard way on an early 2000s POS Ford PowerJoke at work one time. Flippin gay setup i'll tell ya. I swear Ford just likes them boys i don't know what else to tell ya
 

Powerhouse Ranch

3G Connoisseur
Joined
Jan 6, 2021
Posts
1,453
Reaction score
2,516
Location
PA
First Name
Luke
Truck Year
1980 & 1988
Truck Model
C25 & V15
Engine Size
454 & 350
I did the conversion on my M1008/K30 and there was no way the disc conversion out weighs the gigantic drums on that truck.

oh i'm sure that made those sexy trucks 200% sexier
 

Bennyt

Full Access Member
Joined
May 17, 2019
Posts
1,018
Reaction score
1,397
Location
Surprise
First Name
Ben
Truck Year
1977
Truck Model
C10
Engine Size
350
I believe he knows,just trying to give out pointers to help with ground clearance and protect the parking brake.


Correct. Thank you sir!
 

Latest posts

Forum statistics

Threads
41,849
Posts
903,443
Members
33,362
Latest member
Dhatch84
Top