'89 Burb V2500 JB7 Different Pad Options?

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oldretiredafguy

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I put together this little cheat sheet for taking to the parts store. Don't trust most of them to look up the correct application, then be able to discern what their 'puter' says.

JB1 JB3 JB5 JD3 JD5 Brakes

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

There are 2 style calipers and rotors on these trucks after 1980, Standard 1" and HD 1.5" They don't interchange.

For 1/2 Tons..
JB1 - manual brakes, 1" rotors
JB3 = power brakes, 1" rotors
JB5 = power brakes, 1.25" rotors

JB1 BRAKE, MANUAL, DISC/DRUM, 4300 LBS
JB3 BRAKE, POWER, DISC/DRUM, 4600 LBS
JB5 BRAKE, POWER, DISC/DRUM, 6400 LBS
JB6 BRAKE, POWER, DISC, DRUM 7200 LBS
JB7 BRAKE, POWER, DISC, DRUM 8400 L85
JB8 BRAKE, POWER, DISC, DRUM 10000 LBS

The only rear ends that have 13" brakes are the JB7 and JB8 brakes on a 14 bolt full float.

JD5: Brake, Dual Power, Disc/Drum, 6,400 Lbs GVW (Dual Diaphragm Vacuum Booster)
JD6: Brake Hyd Power, Disc/Drum, 7,200 Lbs GVW (Hydro-Boost Booster)
JD7: Brake, Hyd Power, Disc/Drum, 8,400 Lbs GVW (Hydro-Boost Booster)


10 or 12 bolt [rear axles] had either 11.15" x 2.75" for the JB5 or 11.15" x 2" for the JB3.


Hope this helps someone.
 

Wallace6

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Just curious,why would I have jb5 and 7300 gvw? Thanks
 

oldretiredafguy

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Just curious,why would I have jb5 and 7300 gvw? Thanks
You didn't mention if your truck is 2wd or 4wd, or 1500 or 2500? Also, where did the 7300 GVW number come from? Door jamb sticker, RPO sticker? Diesel or gasoline?
 
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Blue Ox

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The only rear ends that have 13" brakes are the JB7 and JB8 brakes on a 14 bolt full float.

Just to add to this, my truck has JD7 brakes with a 13" drum on a 9.5" semi-float axle. 8600 GVW. It's not exclusive to 10.5" full-float axles.
 

Keith Seymore

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Just curious,why would I have jb5 and 7300 gvw? Thanks
You don't.

You have JD5 and 7300 gvw, which is specific to the diesel/hydraboost combination.

K
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Keith Seymore

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I put together this little cheat sheet for taking to the parts store. Don't trust most of them to look up the correct application, then be able to discern what their 'puter' says.

JB1 JB3 JB5 JD3 JD5 Brakes

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

There are 2 style calipers and rotors on these trucks after 1980, Standard 1" and HD 1.5" They don't interchange.

For 1/2 Tons..
JB1 - manual brakes, 1" rotors
JB3 = power brakes, 1" rotors
JB5 = power brakes, 1.25" rotors

JB1 BRAKE, MANUAL, DISC/DRUM, 4300 LBS
JB3 BRAKE, POWER, DISC/DRUM, 4600 LBS
JB5 BRAKE, POWER, DISC/DRUM, 6400 LBS
JB6 BRAKE, POWER, DISC, DRUM 7200 LBS
JB7 BRAKE, POWER, DISC, DRUM 8400 L85
JB8 BRAKE, POWER, DISC, DRUM 10000 LBS

The only rear ends that have 13" brakes are the JB7 and JB8 brakes on a 14 bolt full float.

JD5: Brake, Dual Power, Disc/Drum, 6,400 Lbs GVW (Dual Diaphragm Vacuum Booster)
JD6: Brake Hyd Power, Disc/Drum, 7,200 Lbs GVW (Hydro-Boost Booster)
JD7: Brake, Hyd Power, Disc/Drum, 8,400 Lbs GVW (Hydro-Boost Booster)


10 or 12 bolt [rear axles] had either 11.15" x 2.75" for the JB5 or 11.15" x 2" for the JB3.


Hope this helps someone.
That's really good. Thank you for doing that and posting it up.

K
 

Keith Seymore

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An FYI, brakes always make noise. The trick is to keep it out of the range of human hearing.
One potential solution here is to be hard of hearing.

Another, perhaps better solution, is to turn the radio up.

K
 

Wallace6

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It's a v1500 original diesel but been swapped at some point.
Thanks
 

oldretiredafguy

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It's a v1500 original diesel but been swapped at some point.
Thanks
That explains the 7300 GVWR the diesel got, for the increased HP & increased Torque.
 

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