83 Chevy breaks 2in or 2 3/4in shoes

[American_justice]

I have a 1983 Chevy custom deluxe 2wd long wheelbase. I need to do the front break rotors and pads. I went to auto zone and apparently they need to know what type of rear brake shoes I have on it in order to figure out what type of rotor I need. Don't ask me why, makes no sense to me, and of course they don't know **** about it. Im trying to avoid getting into the rear drums just to check cuz they seem fine and id rather not mess with em. That's why I'm here asking. So please great forum, spread ur wisdom on me like warm butter on toasty buns

Any info is helpful, thanks in advance

 

[American_justice]

So basically I just need to know if i will have a 2in or a 2 3/4in rear shoe on my vehicle

 

[78C10BigTen]

Do you have any brake codes on your spid label in the glove box? Just wingin it here...

 

[American_justice]

Not seeing any kind of identifying label or tag in the glove box. Looks like something might have been here once tho

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[C10MixMaster]

I have a 1983 Chevy custom deluxe 2wd long wheelbase. I need to do the front break rotors and pads. I went to auto zone and apparently they need to know what type of rear brake shoes I have on it in order to figure out what type of rotor I need. Don't ask me why, makes no sense to me, and of course they don't know **** about it. Im trying to avoid getting into the rear drums just to check cuz they seem fine and id rather not mess with em. That's why I'm here asking. So please great forum, spread ur wisdom on me like warm butter on toasty buns

Any info is helpful, thanks in advance

there looking to see if you had heavy duty or standard duty brakes. Measuring the rears is an easy way to tell them apart. Just get both sets and return the one that doesn't fit

 

[Keith Seymore]

That looks like where the camper label used to be.

You should be looking for the Service Parts ID label, or SPID label, which is the one on the right. Some model years and assembly plants they were placed underhood, on the wheel house, so you might check there as well.

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I'll check the brake charts tonight when I get home and see what they say about your truck, but I might need some additional information like engine, trans, and GVW rating.

But - the quickest and most straightforward approach would be to pull a rear wheel, slip the drum off and measure. Or buy both sets, as C10MixMaster suggested.

K

 

[Keith Seymore]

So basically I just need to know if i will have a 2in or a 2 3/4in rear shoe on my vehicle

Power brakes (I assume), or manual brakes?

K

 

[Keith Seymore]

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Gotta know the GVW.

5600 lb rating = JB3 = 2 inch shoes

6000 lb rating = JB5 = 2.75 inch shoes

 

[RoryH19]

If you have the heavy duty system, I have this on my 87, it has larger rotors and drums.
If I recall the rotors will be 1.25" instead of 1".

 

[Keith Seymore]

If you have the heavy duty system, I have this on my 87, it has larger rotors and drums.
If I recall the rotors will be 1.25" instead of 1".

That's what he's trying to figure out.

JB1 (manual) and JB3 (power) = 1" rotors; 2" rears

JB5 = 1.25" rotors; 2.75" rears

K

 

[Keith Seymore]

Here's the complete chart for '83, just for reference (11" x 60").

K

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[gotyourgoat]

Here's the complete chart for '83, just for reference (11" x 60").

K

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What exactly am I looking at?
It looks like Chinese characters.

 

[Keith Seymore]

That is the chart that the brake engineer developed and used as a reference for releasing the part numbers into the production and service systems for all of GM Truck. There is one of these for each model year; I have the charts starting in 1969 (which are handwritten) up through about 2001.

Across the top lengthways are model types; the columns represent the actual part numbers and dimensions, engineering specifications, friction material codes, etc for each component: front system (rotors, calipers); rear system (drums, shoes, wheel cylinders, etc) and apply system (master cylinder, booster, pedal, pedal ratio, combination valve). The attachment in post #8 is a close up of the information related to the OP's truck and questions.

If a person is not conversant in model codes and RPO codes then I guess it will look a bit like Chinese, especially when viewed sideways.

K

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[Ronno6]

I had quite an involved go-round with the brakes on my
'84 C10.
The truck had 1 1/4" rotors but 2" rear shoes.
That dog wouldn't hunt............the rears would always skid before the fronts would engage.
Tried EVERYTHING....literally...........
ONLY thing to cure the problem was changing rear brakes to the wider setup.
Now it is perfect.

Moral of the story: measure your rotor thickness...easy enough to do, and select parts
for that size. That's ALL the parts store should need to know.