Brake help

[grinder1989]

I have an 83 3/4 ton 2wd.  When I called the parts store to get calipers, they asked me if I had a JD6 or JD7 brake system.  I looked all over the truck and couldn't find the option codes.  I'm fine on the back brakes, I know how to measure drums haha.  Which caliper do I need and how do I know which one to get?  Thanks guys. 

[VileZambonie]

Did you look on the spid label in the glove box?

[oldwhity]

If you get to that "point", just take your caliper to the store and compare.

[Irish_Alley]

if you know how to measure the drums then why not do it? thats how they tell them apart on the autozone computer. or are you just saying you don't want to take the drums off thats why your looking for the option code?

[grinder1989]

Did you look on the spid label in the glove box?

There's a label in the glove box, but no option codes.  There is one stuck to the inner fender but no codes for brakes.  FYI, I'm only talking about the calipers.  There are two styles and I can't have my truck sitting in my garage waiting for a part to get ordered, I want to do it all in a day.   I don't care what drums I have on the back because I can measure them and find the parts I need.  The caliper is not as easy to figure out.

[Irish_Alley]

what i was getting at is if you ask a parts store probably autozone for rear shoes then there question what style breaks do you have they will give you a measurement of the rear shoes and you go by that that should tell you what style breaks you have but since you don't want to do it that way does your master cylinder look like any of these top two are for jd6 and jd6 bottom is for the 7


or you can look at the caliper not the location and angle of the break line fitting
"7"

"6"

this parts a guess but it makes sense since the style 7 seams to be the bigger style than the rear shoes should be the 13" ones while the 6 style should be the 11" ones and there are more than two diffrent styles just all that matters for this app is if its 6 or 7
good luck buddy

[Marc]

You could get both and return the one that isn't right when you take the core back. 

[grinder1989]

Thanks guys. 

[Irish_Alley]

You could get both and return the one that isn't right when you take the core back. 

now thats too easy why would he do that

[grinder1989]

Less crap I'd have to deal with.  If I know what to look for, I'll always know what to look for 

[farmallgray]

I have an 83 3/4 ton 2wd.  When I called the parts store to get calipers, they asked me if I had a JD6 or JD7 brake system.  I looked all over the truck and couldn't find the option codes.  I'm fine on the back brakes, I know how to measure drums haha.  Which caliper do I need and how do I know which one to get?  Thanks guys. 

The JB6 system will have 11-5/32" rear drums and the JB7 has 13" drums. That is the easiest way to tell which system you have.