Front brake dragging, 83 GMC - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Jeepwm69 · 06-25-2019, 02:54 PM

Truck is an 83 GMC, not driven much (@38K miles on it). Last week while in town I noticed the left front brake was dragging.

Given the age and what I found nosing around here, figure it's time to replace the rubber lines, and probably do calipers, pads, and maybe rotors at the same time.

AC Delco lines are cheap enough (@$12 each on Rockauto). What kind of calipers and pads do yall recommend? Looks like Delco sells a caliper/hardware/semi metallic pad set, but from what I've heard Delco isn't what it used to be, and these might just be the same crap Chinese parts in a fancy Delco box.

Suggestions?

SCOTI · 06-25-2019, 05:33 PM

Quote:

Originally Posted by Jeepwm69

Truck is an 83 GMC, not driven much (@38K miles on it). Last week while in town I noticed the left front brake was dragging.

Given the age and what I found nosing around here, figure it's time to replace the rubber lines, and probably do calipers, pads, and maybe rotors at the same time.

AC Delco lines are cheap enough (@$12 each on Rockauto). What kind of calipers and pads do yall recommend? Looks like Delco sells a caliper/hardware/semi metallic pad set, but from what I've heard Delco isn't what it used to be, and these might just be the same crap Chinese parts in a fancy Delco box.

Suggestions?

Buy your parts @ a local place that has a warranty on your purchase. No reason to purchase online for wearable items unless you're just looking @ initial purchase price.

For brake stuff, I like Raybestos & Wagner products & use them when possible. Otherwise, house brand w/the best warranty offered.

truckin 79 · 06-26-2019, 11:13 AM

I have been wanting to change my rubber hoses on truck but man do those look like a real pain to get to. I am putting this off as long as I can.

SCOTI · 06-26-2019, 01:13 PM

Quote:

Originally Posted by truckin 79

I have been wanting to change my rubber hoses on truck but man do those look like a real pain to get to. I am putting this off as long as I can.

On a 'Squarebody', they're actually not too bad. Banjo fitting @ the caliper & bulkhead fitting @ the frame. Both are pretty accessible.

**mongocanfly** · 06-26-2019, 03:49 PM

And if you decide to change the hoses be sure to use a proportional valve centering tool before you start bleeding brakes...

Jeepwm69 · 06-27-2019, 10:23 AM

Quote:

Originally Posted by mongocanfly

And if you decide to change the hoses be sure to use a proportional valve centering tool before you start bleeding brakes...

Ah, so these trucks have the same type proportioning valve as my Jeep CJ's.

Good to know. Thanks for that info.

**hatzie** · 06-28-2019, 08:53 AM

Quote:

Originally Posted by Jeepwm69

Ah, so these trucks have the same type proportioning valve as my Jeep CJ's.

Good to know. Thanks for that info.

Likely it's made by the same supplier if not the exact same part.

AMC seemed to use the same parts as the big three in a lot of places. They were operating on a shoestring budget for several decades before they went under.
The 258 in my Eagle wagon used Ford Duraspark ignition parts and a Carter BBD carburetor that many folks swapped out for the Motorcraft 2100 or 2150. The BBD was used on many Chryslers.

Jeepwm69 · 06-28-2019, 12:16 PM

Quote:

Originally Posted by hatzie

Likely it's made by the same supplier if not the exact same part.

AMC seemed to use the same parts as the big three in a lot of places. They were operating on a shoestring budget for several decades before they went under.
The 258 in my Eagle wagon used Ford Duraspark ignition parts and a Carter BBD carburetor that many folks swapped out for the Motorcraft 2100 or 2150. The BBD was used on many Chryslers.

Yeah I have 2100's on two of my three CJ's (the Scrambler only has 5K miles on it so it still has the BBD).

I used a hotter coil and bigger cap/rotor on my Duraspark ignitions on mine. https://www.jeep-cj.com/forums/f2/te...e-11416-print/

I really like those Eagle rigs. Used to be everywhere and cheap, but looks like they're becoming a niche collector car now.

**lolife99** · 06-27-2019, 12:14 PM

And remember there are two different width rotors available for these trucks.
1-1/4” hd rotors and the light duty 1” rotors.
Calipers and bearings are also different.

Jeepwm69 · 06-27-2019, 04:38 PM

I've noticed that most calipers say they're for 11" by 2" rotors OR the regular rotors.

Does that mean heavy duty calipers will fit all rotors, but light duty calipers will not fit the HD rotors?

**lolife99** · 06-27-2019, 05:25 PM

Quote:

Originally Posted by Jeepwm69

I've noticed that most calipers say they're for 11" by 2" rotors OR the regular rotors.

Does that mean heavy duty calipers will fit all rotors, but light duty calipers will not fit the HD rotors?

No.
HD calipers only fit the 1-1/4” rotors.
Calipers have to match the rotors.
Rotors have to match the spindles.
And there’s 2 different spindles also.
No such thing as a 2” wide rotor.

Jeepwm69 · 06-28-2019, 12:18 PM

Quote:

Originally Posted by lolife99

No.
HD calipers only fit the 1-1/4” rotors.
Calipers have to match the rotors.
Rotors have to match the spindles.
And there’s 2 different spindles also.
No such thing as a 2” wide rotor.

I was attempting to interpret how the calipers are listed.

ACDELCO 18R640 {#18035829} Professional; Non-Coated, Includes: Semi-Metallic Pads and Hardware; Reman. Info

FitsFront Left; with 11-5/32in x 2-3/4in Brakes
OrFront Left; Heavy Duty System; w/ 11" X 2" Brakes

ACDELCO 18R639 {#18035828} Professional; Non-Coated, Includes: Semi-Metallic Pads and Hardware; Reman. Info

FitsFront Right; with 11-5/32in x 2-3/4in Brakes
OrFront Right; Heavy Duty System; w/ 11" X 2" Brakes

ACDELCO 18R623 {#18035812, 18R737} Professional; Non-Coated, Includes: Semi-Metallic Pads and Hardware; Reman. Info One of our most popular parts

Front Right; Standard System; w/ 11" X 2" Brakes

**lolife99** · 06-28-2019, 02:05 PM

Quote:

Originally Posted by Jeepwm69

I was attempting to interpret how the calipers are listed.

ACDELCO 18R640 {#18035829} Professional; Non-Coated, Includes: Semi-Metallic Pads and Hardware; Reman. Info

FitsFront Left; with 11-5/32in x 2-3/4in Brakes
OrFront Left; Heavy Duty System; w/ 11" X 2" Brakes

ACDELCO 18R639 {#18035828} Professional; Non-Coated, Includes: Semi-Metallic Pads and Hardware; Reman. Info

FitsFront Right; with 11-5/32in x 2-3/4in Brakes
OrFront Right; Heavy Duty System; w/ 11" X 2" Brakes

ACDELCO 18R623 {#18035812, 18R737} Professional; Non-Coated, Includes: Semi-Metallic Pads and Hardware; Reman. Info One of our most popular parts

Front Right; Standard System; w/ 11" X 2" Brakes

The 11x2-3/4 and 11x2 refers to the rear brake shoe size on those vehicles.
Go out to your truck and measure your rotor width first.

Per RockAuto,...
It looks like 18FR623 and 18FR624 are for the light duty 1" rotors.
And 18FR639 and 18FR640 are for the HD 1-1/4" rotors.

**lolife99** · 06-28-2019, 02:14 PM

Look at this thread also:
http://67-72chevytrucks.com/vboard/s...d.php?t=209390
A lot of parts stores show JB3 or JB5 when referring to brake parts,...

QUOTE:
JB3 is the 1" thick rotors
JB5 is the 1.25" thick rotors

Jeepwm69 · 07-01-2019, 01:34 PM

Quote:

Originally Posted by lolife99

Look at this thread also:
http://67-72chevytrucks.com/vboard/s...d.php?t=209390
A lot of parts stores show JB3 or JB5 when referring to brake parts,...

QUOTE:
JB3 is the 1" thick rotors
JB5 is the 1.25" thick rotors

Thanks! Makes sense.

smokehouse · 07-01-2019, 02:03 PM

the hardest part i had when doing the brakes was that stupid stamped steel nut to unscrew from the rubber brake line that sucked so bad i ended up cutting the rear metal brake line and going to the store and making a new metal line and then i used the stainless steel flex hoses the stopping power is so amazing now. I just did a complete brake job on my suburban and i had to find the correct master mine took the jb6. i know that the banjo bolt do not fit into both the 1" caliper and the 1.25 caliper they are different and the hole inside the bolt is way bigger on the 1.25 than the 1 inch. fyi

06-26-2019, 11:13 AM	#3
truckin 79 Registered User Join Date: Jun 2014 Location: CO Posts: 750	Re: Front brake dragging, 83 GMC I have been wanting to change my rubber hoses on truck but man do those look like a real pain to get to. I am putting this off as long as I can. __________________ 79 Chevy 2wd BIG10 350 TH400

06-26-2019, 03:49 PM	#5
mongocanfly Post Whore Join Date: May 2015 Location: Alabama Posts: 14,674	Re: Front brake dragging, 83 GMC And if you decide to change the hoses be sure to use a proportional valve centering tool before you start bleeding brakes... __________________ Mongo...aka Greg RIP Dad RIP Jesse 1981 C30 LQ9 NV4500..http://67-72chevytrucks.com/vboard/s...d.php?t=753598 Mongos AD- LS3 TR6060...http://67-72chevytrucks.com/vboard/s...34#post8522334 Columbus..the 1957 IH 4x4...http://67-72chevytrucks.com/vboard/s...63#post8082563 2023 Chevy Z71..daily driver

06-27-2019, 12:14 PM	#9
lolife99 67-72 parts collector,… Join Date: Nov 2002 Location: Mid-MO Posts: 22,701	Re: Front brake dragging, 83 GMC And remember there are two different width rotors available for these trucks. 1-1/4” hd rotors and the light duty 1” rotors. Calipers and bearings are also different. __________________ Keith Convert to disc brakes. http://67-72chevytrucks.com/vboard/s...d.php?t=444823

06-27-2019, 04:38 PM	#10
Jeepwm69 Registered User Join Date: Jan 2009 Location: Arkansas Posts: 687	Re: Front brake dragging, 83 GMC I've noticed that most calipers say they're for 11" by 2" rotors OR the regular rotors. Does that mean heavy duty calipers will fit all rotors, but light duty calipers will not fit the HD rotors?

06-28-2019, 02:14 PM	#14
lolife99 67-72 parts collector,… Join Date: Nov 2002 Location: Mid-MO Posts: 22,701	Re: Front brake dragging, 83 GMC Look at this thread also: http://67-72chevytrucks.com/vboard/s...d.php?t=209390 A lot of parts stores show JB3 or JB5 when referring to brake parts,... QUOTE: JB3 is the 1" thick rotors JB5 is the 1.25" thick rotors __________________ Keith Convert to disc brakes. http://67-72chevytrucks.com/vboard/s...d.php?t=444823

06-25-2019, 02:54 PM	#1
Jeepwm69 Registered User Join Date: Jan 2009 Location: Arkansas Posts: 687	Front brake dragging, 83 GMC Truck is an 83 GMC, not driven much (@38K miles on it). Last week while in town I noticed the left front brake was dragging. Given the age and what I found nosing around here, figure it's time to replace the rubber lines, and probably do calipers, pads, and maybe rotors at the same time. AC Delco lines are cheap enough (@$12 each on Rockauto). What kind of calipers and pads do yall recommend? Looks like Delco sells a caliper/hardware/semi metallic pad set, but from what I've heard Delco isn't what it used to be, and these might just be the same crap Chinese parts in a fancy Delco box. Suggestions?

07-01-2019, 02:03 PM	#16
smokehouse Registered User Join Date: Sep 2018 Location: bowling green, ky Posts: 62	Re: Front brake dragging, 83 GMC the hardest part i had when doing the brakes was that stupid stamped steel nut to unscrew from the rubber brake line that sucked so bad i ended up cutting the rear metal brake line and going to the store and making a new metal line and then i used the stainless steel flex hoses the stopping power is so amazing now. I just did a complete brake job on my suburban and i had to find the correct master mine took the jb6. i know that the banjo bolt do not fit into both the 1" caliper and the 1.25 caliper they are different and the hole inside the bolt is way bigger on the 1.25 than the 1 inch. fyi



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