Brake Code

[daleearnhardt01]

Since the search function is so crappy Ill have to ask here. Buddy has a 89 3/4 4x4 Burby. I forget where to look to find out the brake code (ie. JB7 or JB6..etc) Where is that info at? /forums/images/graemlins/peace.gif /forums/images/graemlins/peace.gif /forums/images/graemlins/peace.gif

 

[TruckNutzDude]

If you have a 14 bolt full floater in the back it is JB7. If you have a semi-floating 14 bolt the code is JB6. The other way to tell is if you have the 13" drums or the puny 11" ones. /forums/images/graemlins/thumb.gif

 

[daleearnhardt01]

Interesting...glove box says JB7 but its a SF axle so we shall see when I get it all apart for him..

 

[mosesburb]

It should be a JB7 on a 3/4T, regardless of which diff it has. The only relevance I have seen to which diff you got is small blocks got the 14SF and the big blocks got the 14FF, but they all had the same brakes on the 3/4T. This is not gospel, just what I have seen over the years at the shop.

 

[84_Chevy_K10]

[ QUOTE ]
It should be a JB7 on a 3/4T, regardless of which diff it has. The only relevance I have seen to which diff you got is small blocks got the 14SF and the big blocks got the 14FF, but they all had the same brakes on the 3/4T. This is not gospel, just what I have seen over the years at the shop.

[/ QUOTE ]

Well it's wrong. 3/4 tons come with 11 x 2 1/2 or 13 x 2 1/2 brakes. 11" are less common but they're out there.

 

[daleearnhardt01]

This truck did have JB7 brakes.....

 

[mosesburb]

Your information has an inaccuracy in it as well. You stated the 11" diameter drums have a 2-1/2" width when it is actually 2-3/4". These do exist, but I have never got a set of 13" shoes sent back as wrong parts on a 3/4T 4x4. Typically the only time JB6 shows up on a 3/4T is either 2wd or a G-van.

 

[ugly_blazer]

As you said, I had a 2wd 3/4 ton with the jb6 system. I also have never seen it on a 4x4.