JB5 or JD5 Brakes???

[SpartanTravis]

I have an 84 K10 I'm pretty sure I have a vacuum brake booster.


I'm trying to find out if my brake booster is a JD5 or a JB5. If anyone knows, please help me out. I have none of the identification stickers in the door jam, glove box, etc.

Here is my vin in case it help.
2GCEK14H1E1141337


Thanks,
Travis

[enaberif]

http://forum.73-87chevytrucks.com/smforum/index.php?topic=28592.0

[SpartanTravis]

Thanks enaberif. So if I have a JB5 then I have to have the rotors and calipers to match correct?


Thanks,
Travis

[enaberif]

Not necessarily but its best to keep the system the way it was.

[Irish_Alley]

if i had to guess i would think JB3. JB3 is for gvw of 4600lbs, while JB5 is for 6400lbs. the highest a ½ ton truck went to was 6200 and that was on the "BIG TEN".

[SpartanTravis]

So if I was going to upgrade the system to a JB5, what all would I need to change? ie. Brake booster, master cylinder, calipers, rotors, drums, lines?


Thanks,
Travis

[Irish_Alley]

let me ask you this, why? and what parts do you have now?

[SpartanTravis]

Well I already have the rotors, drums, pads, and shoes I got from a buddy for next to nothing. So if I all I need is a brake booster and a master cylinder then I'll fork out for them.


Thanks,
Travis

[Irish_Alley]

curious but are  they 6 lug or 8?

[Irish_Alley]

i dont think the brake upgrade would be worth it only for 1800 lb difference.

[SpartanTravis]

They're 6 lug.


Thanks,
Travis

[Irish_Alley]

will add this, i think the jb3, jb5 and jb6 use the same booster/cylinder.

to be clear youre talking about the new parts being 6 lug or the old or both?

[SpartanTravis]

All the new parts are 6 lug.


Thanks,
Travis

[Irish_Alley]

how do you know what type of brakes the new parts are? what the gvw of the new brakes? have you compared them to yours? (ie rotor size)

[SpartanTravis]

He still had all the receipts for everything. I just looked them up. Everything is for a JB5. The brakes are 1 1/4 inch.


Thanks,
Travis