Drum brakes on a 1979 Big 10?

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.

Grit dog

Full Access Member
Joined
May 18, 2020
Posts
6,947
Reaction score
12,178
Location
Auburn, Washington
First Name
Todd
Truck Year
1986, 1977
Truck Model
K20, C10
Engine Size
454, 350
That's as close to a question that's never been asked as I could imagine...
I'll have to answer a question with a question.
WHY?
 

Goldie Driver

Full Access Member
Joined
Mar 19, 2018
Posts
4,042
Reaction score
6,633
Location
Houston, Texas
First Name
Britt
Truck Year
1980
Truck Model
GMC K1500 Suburban
Engine Size
350
1. Room for a 15X3.5 draglite rim
2. Less drag
3. Weight

I'd actually be curious to see what the weight difference would be between the drum brake hardware and drum versus the rotor, pads, and caliper.

Having said that, to the best of my knowledge all the squares had disc brakes up front. To go to drum I believe new spindles would be required - not sure if the prior generations would work or not.

I'd also assume that a new drum brake proportional valve would be required.

I am not a fan, but would Centerline wheels be an easier solution?
 

Mark Jones

Full Access Member
Joined
Dec 2, 2018
Posts
179
Reaction score
502
Location
Horse Shoe Bay Tx/Thousand Oaks Ca
First Name
Mark
Truck Year
1979
Truck Model
C10
Engine Size
327
I'd actually be curious to see what the weight difference would be between the drum brake hardware and drum versus the rotor, pads, and caliper.

Having said that, to the best of my knowledge all the squares had disc brakes up front. To go to drum I believe new spindles would be required - not sure if the prior generations would work or not.

I'd also assume that a new drum brake proportional valve would be required.

I am not a fan, but would Centerline wheels be an easier solution?
I was thinking my caliper would hit the back of the rim, but after looking at it again I think it will clear, redrilling my rotors for 5/4 3/4 pattern.
 

Turbo4whl

Supporting Member
Supporting Member
Joined
Oct 30, 2019
Posts
3,120
Reaction score
7,240
Location
Downingtown, PA
First Name
Wayne
Truck Year
1974
Truck Model
Jimmy
Engine Size
350
1. Room for a 15X3.5 draglite rim
2. Less drag
3. Weight

Keep the disc's

#1 Add a wheel spacer, or grind metal off the caliper.

#2 Loosen the front wheel bearing adjustment. GM's original design for disc brakes called for a looser adjustment. The slight wobble pushes the pads back.

#3 Buy aluminum/ alloy calipers.
 

nabeshin

functioning lunatic
Joined
Jan 23, 2020
Posts
464
Reaction score
859
Location
Cozad, Nebraska
First Name
Grae
Truck Year
1976
Truck Model
K10
Engine Size
400
Might as well get a wooden block on a lever to drag on the tire like some old stage coach.

Anyway, disk brake piston seals are designed to pull the pads back ever so slight so that they do not drag/stay on until worn clear.
 

Turbo4whl

Supporting Member
Supporting Member
Joined
Oct 30, 2019
Posts
3,120
Reaction score
7,240
Location
Downingtown, PA
First Name
Wayne
Truck Year
1974
Truck Model
Jimmy
Engine Size
350
Might as well get a wooden block on a lever to drag on the tire like some old stage coach.

Anyway, disk brake piston seals are designed to pull the pads back ever so slight so that they do not drag/stay on until worn clear.

Yes, newer designs always have improvements. GM service manual/bulletin in the early 1970's clearly stated, looser adjustment on the wheel bearings.
 

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
5,385
Reaction score
8,591
Location
kansas
First Name
Rick
Truck Year
1975
Truck Model
c20
Engine Size
350
I thought he already decided against going drum because he saw he had the clearance he needed.But if you want to you can use 67-70 c spindles,brakes,balljoints,hoses,outter tie rod ends, master cylinder. And proportoning valve.Lots of work and money, but it's your truck and your time and money.
 

shiftpro

Full Access Member
Joined
Aug 31, 2012
Posts
4,855
Reaction score
6,092
Location
BC Canada
First Name
shiftpro
Truck Year
73-87
Truck Model
1500, 2500, 3500
Engine Size
350, 383, 454, 496!
#2 Loosen the front wheel bearing adjustment. GM's original design for disc brakes called for a looser adjustment. The slight wobble pushes the pads back.


That's one of the craziest things I've ever heard, that actually makes sense.
 

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
5,385
Reaction score
8,591
Location
kansas
First Name
Rick
Truck Year
1975
Truck Model
c20
Engine Size
350
That's one of the craziest things I've ever heard, that actually makes sense.

It's also a sign of worn out wheel brgs, you go around a corner or hit some bumps and your pedal height is low like there's air in the lines, but nope the rotor leaned and pushed your piston in.
 

Mark Jones

Full Access Member
Joined
Dec 2, 2018
Posts
179
Reaction score
502
Location
Horse Shoe Bay Tx/Thousand Oaks Ca
First Name
Mark
Truck Year
1979
Truck Model
C10
Engine Size
327
Keep the disc's

#1 Add a wheel spacer, or grind metal off the caliper.

#2 Loosen the front wheel bearing adjustment. GM's original design for disc brakes called for a looser adjustment. The slight wobble pushes the pads back.

#3 Buy aluminum/ alloy calipers.
Thanks for the info, actually my rotors are very free turning, just need to get the 15X3.5 rim on there.
 

Mark Jones

Full Access Member
Joined
Dec 2, 2018
Posts
179
Reaction score
502
Location
Horse Shoe Bay Tx/Thousand Oaks Ca
First Name
Mark
Truck Year
1979
Truck Model
C10
Engine Size
327
I thought he already decided against going drum because he saw he had the clearance he needed.But if you want to you can use 67-70 c spindles,brakes,balljoints,hoses,outter tie rod ends, master cylinder. And proportoning valve.Lots of work and money, but it's your truck and your time and money.
Thanks for the information! If I can't get the rims to clear the calipers thats what I will do.
 

Ricko1966

Full Access Member
Joined
Apr 11, 2017
Posts
5,385
Reaction score
8,591
Location
kansas
First Name
Rick
Truck Year
1975
Truck Model
c20
Engine Size
350
Thanks for the information! If I can't get the rims to clear the calipers thats what I will do.
Wheel spacers would be so much easier and cheaper, if you don't like the aluminum ones readily available. I have made my own before, take a junk rotor or drum, stick it in the brake lathe and turn it until it's just a 6 inch plate with holes in it.
 

Latest posts

Forum statistics

Threads
44,083
Posts
949,059
Members
36,163
Latest member
texczech
Top